Autodesk Moldflow Insight 2010 Std2 Practice

Autodesk MoldflowInsight Standard 2 P RACTICE FOR R ELEASE 2010 February 2009 © 2009 Autodesk, Inc. All rights reserved. Except as otherwise permitted by Autodesk, Inc., this publication, or parts thereof, may not be reproduced in any form, by any method, for any purpose. Certain materials included in this publication are reprinted with the permission of the copyright holder. Trademarks The following are registered trademarks or trademarks of Autodesk, Inc., in the USA and other countries: 3DEC (design/logo), 3December, 3December.com, 3ds Max, ADI, Alias, Alias (swirl design/logo), AliasStudio, Alias|Wavefront (design/logo), ATC, AUGI, AutoCAD, AutoCAD Learning Assistance, AutoCAD LT, AutoCAD Simulator, AutoCAD SQL Extension, AutoCAD SQL Interface, Autodesk, Autodesk Envision, Autodesk Insight, Autodesk Intent, Autodesk Inventor, Autodesk Map, Autodesk MapGuide, Autodesk Streamline, AutoLISP, AutoSnap, AutoSketch, AutoTrack, Backdraft, Built with ObjectARX (logo), Burn, Buzzsaw, CAiCE, Can You Imagine, Character Studio, Cinestream, Civil 3D, Cleaner, Cleaner Central, ClearScale, Colour Warper, Combustion, Communication Specification, Constructware, Content Explorer, Create>what's>Next> (design/ logo), Dancing Baby (image), DesignCenter, Design Doctor, Designer's Toolkit, DesignKids, DesignProf, DesignServer, DesignStudio, Design|Studio (design/logo), Design Web Format, DWF, DWG, DWG (logo), DWG Extreme, DWG TrueConvert, DWG TrueView, DXF, Ecotect, Exposure, Extending the Design Team, FBX, Filmbox, FMDesktop, Freewheel, GDX Driver, Gmax, Green Building Studio, Heads-up Design, Heidi, HumanIK, IDEA Server, i-drop, ImageModeler, iMOUT, Incinerator, Inventor, Inventor LT, Kaydara, Kaydara (design/logo), Kynapse, Kynogon, LandXplorer, LocationLogic, Lustre, Matchmover, Maya, Mechanical Desktop, MotionBuilder, Movimento, Mudbox, NavisWorks, ObjectARX, ObjectDBX, Open Reality, Opticore, Opticore Opus, PolarSnap, PortfolioWall, Powered with Autodesk Technology, Productstream, ProjectPoint, ProMaterials, RasterDWG, Reactor, RealDWG, Real-time Roto, REALVIZ, Recognize, Render Queue, Retimer,Reveal, Revit, Showcase, ShowMotion, SketchBook, SteeringWheels, Stitcher, StudioTools, Topobase, Toxik, TrustedDWG, ViewCube, Visual, Visual Construction, Visual Drainage, Visual Landscape, Visual Survey, Visual Toolbox, Visual LISP, Voice Reality, Volo, Vtour, Wiretap, and WiretapCentral. The following are registered trademarks or trademarks of Autodesk Canada Co. in the USA and/or Canada and other countries: Backburner, Discreet, Fire, Flame, Flint, Frost, Inferno, Multi-Master Editing, River, Smoke, Sparks, Stone, and Wire. The following are registered trademarks or trademarks of Moldflow Corp. in the USA and/or other countries: Moldflow MPA, MPA (design/logo), Moldflow Plastics Advisers, MPI, MPI (design/logo), Moldflow Plastics Insight, MPX, MPX (design/ logo), Moldflow Plastics Xpert. Disclaimer THIS PUBLICATION AND THE INFORMATION CONTAINED HEREIN IS MADE AVAILABLE BY AUTODESK, INC. "AS IS." AUTODESK, INC. DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE REGARDING THESE MATERIALS. About this manual The Autodesk Moldflow Insight Standard 2, Practice manual is designed with the new Moldflow user in mind. In creating this manual, our goal was to introduce you to some basic plastic flow and design principles in addition to skills needed to translate, analyze and interpret models. There is a significant amount of information in this manual, more information than can be absorbed during the class. This manual should be useful as a handy desk reference when back in the office. Using this manual This manual is separated into several chapters and appendices. Each of the chapters covers a specific topic and includes the following sections: Aim Describes the learning objectives of the chapter. Why Do It Outlines the reasons for following the prescribed guidance, suggestions, and methodology within the chapter. Overview A complete outline of what will be covered within the chapter. Practice This section contains hands-on exercises used to reinforce what was learned. The practice section guides the user through the steps necessary to complete a project. v Formatting used in this manual Tasks : To perform a step on the computer 1. When the Task icon is shown, below it is a list of numbered steps to complete the task. 1.1. Tasks can have a sub-step, • A bulleted list provides information on a step, or a non-sequential actions to be done, h A second level bulleted list to provide information on a sub-step. 2. A task is used in the practice section of a chapter to indicate steps to be done on the computer. Bulleted lists • A bulleted list contains a number of items that have no particular order. • It does not represent a list of steps that have to be followed in sequence. Ruled paragraph Text from a computer screen is shown between ruled lines. Tip / A tip is a useful piece of information that is normally associated with a task or procedure. Something that can be done to make a task easier or more efficient. Note 3 A note is generally used to highlight some background or theoretical information. vi ige Paper_Holder.igs Grabit. In each folder.sdy Results needed Mat1804.igs phone.igs Snap_Cover.igs Dustpan.igs Light_holder.21000.sdy Cool Boot.mpi file with the same name as the folder.udb Mat1805.sdy Lid. The table below shows the required folders.21000.udb DOE Cap.igs Cover.sdy Family_Tools Box. All the results that need to be run will be provided in class. However if for some reason the results are not available.Training files setup The files required for the Autodesk Moldflow Insight Standard 2 class are organized into several folders. The mpi file is the database of the Project pane in Synergy.sdy Packing_Optimization Projects SC Fill.sdy Fill + Pack + DOE on Cap Plate.igs vii . there will be a *. Each folder has the files necessary for one chapter.igs Cap.sdy Drawer.sdy Cool SC3 Fill.sdy None SC3 Flat Prof.igs reel.igs Drawer. and results necessary for the class.sdy None SC Flat Prof. Table 1: Files Required for the Autodesk Moldflow Insight Standard 2 Class Folder name Files Needed Database_Management Cover.igs Change_tray. translation and study files.sdy Insert Overmolding Insert DD Fill + Pack on Connector 3D Pre-Run Connector DD Connector 3D Pre-Run Multiple_Gates door_panel. they can be obtained by analyzing the necessary studies. MF Back & Logo Pre-Run.Table 1: Files Required for the Autodesk Moldflow Insight Standard 2 Class Folder name Files Needed Results needed Two-Shot Box DD Fill + Pack + Overmolding Fill +Pack on Connector 3D Pre-Run. Window DD Box & Window Pre-Run MF Logo DD MF Back DD MF Back & Logo Pre-Run MF Back & Logo Test match viii MF Back & Logo Test match . ..Packing Optimization.............................. 101 Evaluation Sheet ................................................................................. 45 Competency check .....................................................................21 Competency check ... 63 Practice ..................................................................................14 Building the family tool model ................................... 61 CHAPTER 4 Packing Optimization ................................................................................................... 13 Design criteria ....................5 Competency check ...........................................................................................Multiple Gates ......... 25 Evaluation Sheet .......................................... 1 Practice .................................................... 27 CHAPTER 3 Multiple Gates ..................v Formatting used in this manual ............................................................... 103 ix ......................... 33 Door Panel ......................................................................Packing Optimization...................................................................................................................................Family Tools ................................................................................................................................................................................................................................................................Database Management .........................................................................................................................................................................................................19 Analyzing the tool ...................... 29 Practice ....................................................Contents About this manual ..........................................vii CHAPTER 1 Database Management ....... 65 Snap cover with a Dual Domain mesh ......................... 59 Evaluation Sheet ..............................................................................................................................Database Management .........13 Project setup ...................... 3 Setup ........................................................................................................................................................................ 9 CHAPTER 2 Family Tools ............... 85 Competency check ....................................................Packing Optimization......................................Database Management..........................vi Training files setup ...........................v Using this manual ......5 Read in a Personal Database material into a study ............................................................................................................... 11 Practice ...............................................................................................................................................................................................................Family Tools ............................................................................................................................................Multiple Gates ................................................................................................................................................................................................Multiple Gates ....................................................... 7 Evaluation Sheet ................................13 Finding molding conditions and optimizing the parts ...................3 Edit a material property ........ 31 Drawer Model .................................................................................... 67 Snap cover with a 3D mesh .........................................................................................................................................Family Tools .....................3 Creating a personal database ... ........... Answers................182 Find a gate location and process settings for the phone housing model ............................................................................................................................189 Index ....................................................................... Reviewing the results of the cap ..........................................................184 Optimize a 4-cavity tool for the Snap Cover model ........................Design of Experiments (DOE) Analysis........DOE .............................................................................................. 107 Connector ............ 129 Box with window.........................................................171 Optimize the 8-cavity tool for cap ........155 Practice ............................. 109 CHAPTER 6 Two-Shot Sequential Overmolding ................................................................................................................................................... Plate .........................................................................191 x ..........................188 What You’ve Learned ........................105 Practice ........................................................................183 Find a gate location and size the manifold for the reel model ........................................................................................................... Evaluation Sheet ............................................................................CHAPTER 5 Part Insert Overmolding .............................Part insert overmolding..........................................................................................................186 Find gate locations and balance runners for the door panel model .......................176 Determine gate locations for a chest of drawers .........................................................................................................................................174 Find the gate location and size the runner system for a cover ............................................................................................................................................................................................179 Determine type of tool and gate location for the Grab-it model ........................................ 139 CHAPTER 7 Design of Experiments (DOE) Analysis ............... 157 158 160 164 165 167 CHAPTER 8 Projects ............... 131 Moldflow logo........127 Practice .........................................................178 Finding a gate location for a dustpan .......Two-Shot Sequential Overmolding..................................................................................................................................................................................................................................................................169 Finding a gate location on a boot part ............181 Determine the gate location for the paper holder model to minimize weld lines ...........................................................DOE ..............................180 Determine the gate location for a light holder ...................................................................... Competency check .............................................172 Determine gate location and molding conditions for a change tray ........................................................ CHAPTER 1 Database Management Aim The aim of this chapter is to create or edit databases. Most of the time this is a thermoplastic material. Why do it Customizing databases allows you to create material that is not in standard databases. or in the case of geometry databases. create the standard geometry you use. In this chapter. editing and using databases. You can even edit the defaults for all parameters that are used within the program. you will look at the methods available for working with the databases. Many times you may start by copying an existing material or database record and then modify it. You may also create a new database and enter all the information manually. but it could also be geometry/mesh properties. Database Management 1 . Editing databases can be done so you can run an analysis on a custom material. The method used will depend on what you are editing and why. or to change the values of something that is in a standard database. Overview There are several methods available for creating. 2 Chapter 1 . To open the cover model 1.1. Select the Property Type field to Thermoplastics Material. The standard database is opened automatically. Click on the file Cover. sdy.mpi. 3. 2. Click the OK button. Click File ¨ Preferences. Rotate the model around to review the geometry. To read in existing UDB databases 1. 2.Practice . • The Properties dialog opens as shown in Figure 2. 5. Double click the project file Database_Management. 3. Practice . 6. Ensure the active units are set to metric units. Creating a personal database To create a personal material database 1. 4. Click (File ¨ Open Project) and navigate to the folder My AMI 2010 Projects\AMI Standard 1\Database_Management. 3.1.Database Management 3 . Ensure the Category field is set to Material in the drop-down menu. Navigate to the Database management folder. 2. See Figure 1. Click to the right of the database name field. h This is the folder in which Synergy is open. Click the Save button.Database Management Below are 3 short examples of working with personal databases Setup To open a project 1. 2. Click • button to access all other thermoplastic databases. and click Open. Click Tools ¨ New Personal Database. 2. Name your personal database by clicking on and typing mymatdb. udb database. Click the • icon again and read in mat1805. hold down the Ctrl key while clicking on multiple entries. / To select more than one entry. 4.udb then click the open button.3. Click the button twice to transfer the material to your personal database in the top half of the dialog making two copies.21000. Copy that material to the personal database.udb. 5. • The contents of this database should now be in the lower half of the properties dialog.udb is the type of file you would get from Moldflow Plastics Labs when you had a material tested. 3 The file mat1804. open the search criteria dialog and clear the filters. Figure 1: New database dialog 4 Chapter 1 .2100.21000. Highlight the material in the mat1804. / If you have read in a database and don’t see any materials or not all of them. Click on the file mat1804.21000. 6. Click OK. Double-click (Materials) to select a material. To edit a material 1. Change the Mold surface temperature from 42. Click to highlight the second copy of the Styron 693. If the cover study is not open. 7.5ºC to 50ºC 5.Database Management 5 . Read in a Personal Database material into a study To find the material 1. 6. Click on the Recommended Processing tab. 10.Figure 2: Properties dialog Edit a material property In the mymatdb database. Change the Melt temperature from 225ºC to 250ºC. 3 The Name field in the thermoplastic material dialog is the description field from a search listing. click on the icon in the project view to open it. 2. Change the Name to Styron 693: Changed Mold and Melt. 2. 9. Change the Trade name to Styron 693mod. there should be two copies of the material Styron 693. 3. For the material you just entered. Click the button. the description is Styron 693: Changed Mold and Melt. 8. Practice . Click on the Description tab. Click OK on the Property’s dialog to close the dialog and finish the editing. 4. This should find your database Mymatdb 6. These are the original values. 2. Tab to the Trade name field. Tab to the Trade name field. Click Cancel to close the Process Settings dialog. 6 Chapter 1 . 7. Double-click (Process Settings). type my. Double-click (Materials) to select a material. 6. • They should be 42. Click OK to select the material. Click OK to select the material. Check the value of the Mold surface temperature and Melt temperature. Click Cancel to close the Process Settings dialog. Check the value of the Mold surface temperature and Melt temperature. 3. 5. To check the processing conditions 1. type my. 5. To check the processing conditions 1. Double-click (Process Settings). To read in the second Styron 4. In the Manufacturer field. Select Styron 693. 3. 4. 2. 8. This should find your database Mymatdb. In the Manufacturer field. These are the modified values.3. • They should be 50ºC and 250ºC respectively. Select Styron 693mod.5ºC and 225ºC respectively. What would be the procedure necessary to create a database for standard edge and tunnel gates your company uses? Practice .Database Management 7 .Database Management 1.Competency check . 8 Chapter 1 . Database Management 1. 8. Click the Databases button to open the standard cold gate database. Practice . 7. Select the property type Cold gate. 2.Evaluation Sheet . Exit the dialog. 6. Copy an edge and tunnel gate (subgate) that are close to the correct properties. 5. (Optional). 4. Edit the properties as necessary.Database Management 9 . Click Tools ¨ New personal database. Enter a database name such as Mygates. Select the category Mesh properties. (Optional). What would be the procedure necessary to create a database for standard edge and tunnel gates your company uses? 1. 3. 10 Chapter 1 . optimize the part filling. so that both cavities fill in the same amount of time and pressure. Why do it The purpose of a family tool is to reduce the number of molds needed by combining multiple parts (two or more) into a single mold. using the combined part volumes. Change to flow rate control. The runner balancing procedure being discussed in this chapter can be applied to both Dual Domain and midplane models. and find the part volumes. 3. The reasoning behind this is usually due to cost reduction measures. Add the models together and create the runner system for the new model. This chapter demonstrates how to overcome this challenge by following these steps: 1. 2. Family tools can be analyzed in 3D but their runners can't be balanced in the methods discussed in this chapter. and run a Fill analysis. it is necessary to balance the filling of the multiple cavities via the runner system. In this practice. Although it is possible to place two or more different parts into the same mold. Typically. you will optimize process settings for a family tool.CHAPTER 2 Family Tools Aim In this chapter you will create a family tool and size the runners. it will cause a problem with unbalanced filling. Run a Fill analysis for both parts to verify that the process settings selected work. A Dual Domain version of the models can be created for the purpose of balancing the runners then verified in the 3D model. Overview This chapter uses midplane models in the practice. the parts will be assembled together. Therefore. 4. The main challenge in using family tools is that the parts usually have different volumes and require different pressures to fill. Use the Molding Window analysis to find a set of processing conditions that will work for both parts. and build and balance its runner system. Family Tools 11 . it may be more efficient to size the runners manually. Size the runners to achieve the desired balance using flow rate and the runner balancing. 12 Chapter 2 .5. 3 For some larger family tools where each part has multiple gates. Practice - Family Tools In this section, you will analyze the Box and Lid and balance the runner system for the two cavity family tool. Design criteria Determine the molding conditions that will work for both parts to mold high quality parts. Build and size a runner system so both parts fill at the same time. The mold will be a 3-plate tool. Project setup To open a project 1. Click (File ¨ Open Project) and navigate to the folder My AMI 2010 Projects\AMI Standard 1\Family_Tools. 2. Double-click the project file Family_Tools.mpi. 3. Click File ¨ Preferences. 3.1. Ensure the active units are set to metric units. 3.2. Click on the Directories tab. 3.3. Ensure the Default to project directory box is checked. • By having the box checked, the import dialog will open in the project directory. The next task loads a workspace customized for training classes. Primarily, it introduces you to the toolbars. This is an optional task. To load a workspace for training (optional) 1. Click Tools ¨ Workspace ¨ Open. 2. Select Other... in the Type field. 3. Navigate to the Workspaces folder containing the project folders for this class and click OK. • For example My AMI 2010 Projects\AMI Standard 1\Workspaces. Practice - Family Tools 13 4. Select the workspace file Training Workspace and click Open. • The workspace will load. Primarily, it opens a series of toolbars and leaves them undocked so you can see the name of the toolbars. Toolbars with the word Custom in the name are not standard toolbars but were created as an example of tool bars that can be made. The toolbars include: • Standard. • Viewer. • Animation • Precision View • Viewpoint. • Selection • Scaling. • Custom General. • Custom Results. • Custom Mesh Diag. • Custom Mesh Tools. • Custom Locking. 5. Click and drag the toolbars and dock them where you would like them. • Typically the Viewer toolbar is docked vertically between the Tasks panel and the display area. The rest are typically docked below the menu bar. 3 To get back to the default layout, click Tools ¨ Workspace ¨ Open and in the Moldflow Insight workspaces type, select Defaults. To review the model 1. Open both models. 2. Investigate the model geometry using the model manipulation tools. Finding molding conditions and optimizing the parts The molding conditions will be found by using the molding window analysis. The box and lid will be analyzed separately, then the Molding window results will be compared to find the same conditions that work for both parts. The molding window will be done twice for both parts. The first time with default options. From this, the injection time range will be determined. Then, a molding window analysis will be run with specified ranges for mold and melt temperatures, and injection time. The preferred and feasible molding windows will also be defined. The part geometries are very simple for these parts so part optimization is just a matter of running a fill analysis to make sure the molding conditions are good. For more complex parts, optimization may involve solving any type of flow problem that is found. To run a molding window analyses on the box with default conditions 1. Activate the Box study. (File ¨ Save study as) and enter Box MW1. 2. Click 3. Click (Analysis Sequence) and select Molding Window. 4. Click 14 Chapter 2 (Select material) and find BASF, Luran 368 R. 5. Click (Start Analysis) to run the Molding Window analysis. To view the results for the box 1. Open the Analysis Log and record in Table 1, the range of mold and melt temperatures analyzed. 2. Click Pressure drop, maximum (molding window):XY Plot to display it. 3. Click (Results ¨ Plot Properties). 4. Move the Injection time slider to find the minimum and maximum time plotted. 5. Record the minimum and maximum times in Table 1. 6. Check the Injection time box and move the sliders to ensure the pressure is not too high. 7. Click Close to exit the Explore Solution Space dialog. To run a molding window analyses on the lid with default conditions 1. Activate the Lid study. 2. Click 3. Click 4. Click 5. Click (File ¨ Save study as) and enter Lid MW1. (Analysis Sequence) and select Molding Window. (Select material) and find BASF, Luran 368 R. (Start Analysis) to run the Molding Window analysis. To view the results for the Lid 1. Click Pressure drop, maximum (molding window):XY Plot to display it. 2. Click (Results ¨ Plot Properties). 3. Move the Injection time slider to find the minimum and maximum time plotted. 4. Record the minimum and maximum times in Table 1. 5. Compare the injection time ranges and determine the minimum and maximum common to both studies. 6. Record the values in Table 1. Practice - Family Tools 15 Table 1: Molding conditions notes Parameter Value Box Mold temperature range analyzed Box Melt temperature range analyzed Box Injection time range analyzed Lid Injection time range analyzed Combined injection time range to analyze To run a molding window analysis on the box with specified parameters 1. Activate the Box MW1 study. 2. Click (File ¨ Save Study). 3. Click (File ¨ Save study as) and enter Box MW2. 4. Double-click (Process Settings) in the Study Tasks pane. 4.1. Click the Edit button in the Injection molding machine frame. 4.2. Click the Hydraulic Unit tab. 4.3. Set the maximum machine injection pressure to 140 MPa. 4.4. Click OK to exit the dialog. 5. Set the Mold temperature range to analyze to Specified, and enter the range recorded in Table 1. 6. Set the Melt temperature range to analyze to Specified, and enter the range recorded in Table 1. 7. Set the Injection time range to analyze to Specified, and enter the range recorded in Table 1. 8. Click the Advanced options button. 8.1. Set the injection pressure factor to 0.8 in the Feasible molding window. 8.2. Set the injection pressure factor to 0.5 in the Preferred molding window. 8.3. Set the Flow front temp. Maximum drop to 20ºC. 8.4. Set the Flow front temp. rise limit to 2ºC 8.5. Click OK to exit advanced options. 8.6. Click OK to exit the Process Settings Wizard. (File ¨ Save Study). 9. Click 10. Click 16 (Start Analysis). Chapter 2 7 seconds on both parts. • The Y-axis for injection time is the same because the time range was specified in the analysis. Set the Cut position to 40ºC. but it works for both. To find one set of process conditions that work for both parts 1. Examine the molding window plots for both the box and lid. • The green area represents preferred conditions for the part. Click OK. 2. Click box. If the analysis was left on automatic. Getting the same range analyzed is the reason the molding window was run twice. when prompted. the time range would be different. Click (View ¨ Lock ¨ All plots) so results in both studies can be manipulated at the same time. and on the slow side for the lid. 3. Ensure the Box MW2 study open and active. The size of the preferred windows is different. Click the Molding window:2D Slice Plot in the study tasks list. Notice how this time is on the fast side for the box. Double-click (Analysis ¨ Set Analysis Sequence) and select Fill. The molding conditions to be used for both parts are: Mold Temperature 40 ºC Melt Temperature 240ºC Injection Time 0. Set the cut axis to Mold Temperature. Click (Results ¨ Plot Properties) for the molding window plot. • The X-axis for melt temperature is the same. and don’t overlap much with the time range.2. 6. Ensure that both the Box MW2 and Lid MW2 studies are open. 3. Click Create a Copy. • Close any additional windows. 5. To run a molding window analysis for the lid 1. as this is a mid range temperature for the Find 0. 7.7 sec.1. Click Window ¨ Tile Vertically. 5. To run a fill analysis on the box 1. 5. 5.3. 2. • (Examine Results) at 240ºC. 4. Repeat the steps in the previous task for the lid model. h A 40ºC mold temperature is a reasonable temperature for both parts.Family Tools 17 . Practice . Double-click (Process Settings Wizard) and enter the following conditions. Name the new study Box Fill. • Pressure at V/P switchover. Double-click (Analysis ¨ Set Analysis Sequence) and select Fill. Ensure all the results are acceptable.2. when prompted. (Start Analysis). Animate the results as necessary. 3. Name the new study Lid Fill. Ensure both the Box Fill and Lid Fill studies are open and all other studies are closed. Click • (View ¨ Lock ¨ All plots). 0. 5. Click Create a Copy. To review results 1.7 sec. 5. 2.7 sec. Rotate. Double-click 6. Plot the following results: • Fill time. 5. 4. pan.4. or zoom each part as necessary to get a good view. 0. 5. 5. Mold Temperature 60 ºC Melt Temperature 245ºC Injection Time. To run a fill analysis on the lid 1. Click Windows ¨ Tile Vertically. (Start Analysis). 3. Double-click 6. Double-click (Process Settings Wizard) and enter the following conditions. • Bulk temperature.1. Results in both studies will be displayed and manipulated at the same time. 18 Chapter 2 . Ensure the Lid MW2 study open and active. Mold Temperature 60 ºC Melt Temperature 245ºC Injection Time. 2. 4. 4. When the Lid was added to the Box model they were automatically in the correct location. Click Mesh ¨ Mesh Statistics.1. 7. 5. 2. Record box volume in Table 2. 3. / It is best to put the parts of the family mold in tool position before they are added together. Click Box Fill to activate it. 2. Click (File ¨ Save study as). Table 2: Volumes Component Volume Box Lid Sum of parts Building the family tool model To add the box and lid models together 1. Record Lid volume in Table 2. Add the part volumes together and record it in Table 2.Family Tools 19 . Select the study Lid Fill and click Open. To determine the volume of the box and lid 1. Enter the name Box Lid. 3 The Box and Lid models were imported into Synergy in tool position. Click (File ¨ Add). 2. 3. Activate the Box Fill study. 4. Practice . 6. Click Lid Fill to activate it. Click Mesh ¨ Mesh Statistics. Ensure the Box Lid study is open and active. Click Modeling ¨ Runner System Wizard. 2. the drops are going to be changed from a runner to gate property. h The runners can be converted to trapezoidal after the balance.1. To prevent the drops from being sized during the balanced one of two things can be done: • The runner sizes can be fixed to their current size. Create the runner system for the box and lid. The runner balance algorithm will not size properties of a Sprue or Gate. 2. For this example. the drops would be sized during the balance. 20 Chapter 2 . 2. Create the runners with a circular cross section that is equal to the height of the runner. using the dimensions shown in Figure 3. Constraining the drops The drops between the part and main runner are tapered. and should not be sized during the balance. Only runners are changed. the property of the drops will be changed to Gate. The Runner creation wizard created the drops with a cold runner property. • The runner property can be changed to a gate property. To build the runner system 1. To prevent the change.2. Figure 3: Runner drawing The drops in the runner system are set to unconstrained. h The runner balance analysis only sizes round runners. If nothing was changed. Tapered features of the feed system should not be changed during a runner balance. 2. Set the Fill/Pack switch-over to by % volume filled at 100%. 2. 2. you may set the switch-over to the desired value. Divide this by the injection time used to fill the parts. as shown in Figure 4. 5. Flow Rate = cc/sec. 4. Select all the elements in either one of the tapered drops. Band Select Figure 4: Selecting elements to change the properties Analyzing the tool A flow rate should be used as the filling control. 4. Select Cold gate on the Change Property Type To dialog. which is 0. 6. • This study will be duplicated for runner balancing.Family Tools 21 . Set the Pack/holding control Profile Settings to % Filling pressure to 100%. 3. 5. Click OK twice accept the change. To run a Flow analysis 1. 3. Practice . Set Filling Control to Flow Rate. Recall the total flow rate from both cavities that you have recorded in Table 2. Once the runners are balanced. Ensure the Box Lid study is open. Enter the flow rate you calculated above.7 seconds. which works better when the pressure does not drop after the switch-over. Double-click (Process Settings Wizard). Repeat the process for the other drop. Right-Click and select Change Property type from the context menu. 3. Record the flow rate below. This will ensure the parts will fill in the time determined as optimum. To calculate the flow rate 1. To fix the drop dimensions 1. • Note how much there is left to fill on the Box. • The pressure spike at about 0. 2. Plot the Pressure at injection location. Click OK. To review results to determine balance inputs 1. Click OK twice.7 seconds corresponds to the lid filling and the box has yet to fill out. 3. 8. Double-click (Start Analysis). 2. However if the runner diameters are too small. • In this case. the balance pressure that will be used is 58 MPa which is slightly above the pressure at the end of fill. Chapter 2 . To balance the runners 1. 5. • Pressure is very sensitive to the runner balance. Notice how the pressure of the lid is very high compared to the box. • 22 If Runner balance is not in the list. • This is an XY plot of the pressure gradient at the injection location. Step the animation from the start of fill until the Lid is just full. Plot the Pressure. the parts with the small runner may not pack out properly. Plot Fill Time. Click (Animate result).7. Double-click the Analysis Sequence icon in the Study Tasks pane. the smaller the runner diameters will be which will save material. click the More button and choose runner balance from the full list of analysis sequences. Select Runner Balance. 3. See Figure 5. Figure 5: Pressure XY graph at the injection location / The higher the balance pressure. 4. 4. Double-click the Process Settings icon in the Study Tasks pane. 4.1. Ensure the filling parameters are correct. 4.2. Click Next. 4.3. Set the target pressure to 60 MPa. 4.4. Click Advanced Options. 4.5. Set the Mill Tolerance to 0.1 mm 4.6. Click OK. 4.7. Click Finish. 5. Double-click (Continue analysis). Review the results To view the Analysis Log results 1. Open the Analysis Log if necessary. 2. Watch the analysis progress or review it when the analysis is done. 3. Review the iteration table. • The last iteration should be below all three tolerances. • If it reached the iteration limit, one more analysis is run with the iteration that had the lowest time imbalance. To review volume change 1. Click on the Volume change result in the Box Lid study. 2. Notice the distribution of volume change. • Only the runners have results, because this was the only thing that could change. • The percent change will be zero if the runner size is fixed. • A negative volume change indicates the runner got smaller, and is generally preferred. • A positive volume change indicates the runner has gotten larger and in generally an indication that the balance (target) pressure is too low. To view the thickness changes 1. Double-click on the Box Lid (Runner Balance) study to open it. 2. Rotate the model as necessary to see the runners and parts. A good rotation is -70 -25 -10. Practice - Family Tools 23 3. Plot the thickness diagnostic. 3.1. Click the Tools tab. 3.2. Click (Mesh Diagnostic). 3.3. Select Thickness Diagnostic. 3.4. Click Show. 4. Click (Examine result). 5. Click on the runners. • Notice how both are less than 6 mm, (the original sizes), hence the negative volume in the volume change plot. To plot fill time 1. Click the Fill time result. 2. Click • (Animate). Notice how the flow fronts are very balanced compared to the first analysis. To plot pressure 1. Click the Pressure at V/P switchover result. • Notice how the Box fills last. 2. Click (Examine result). 3. Click on the parting line of the lid. • Notice that the pressure is just above zero, while there is a noticeable portion of the box not filled yet. To review other results 1. Plot other results to see the influence of the balance. 2. If desired, tile the windows and lock the studies: • Box Lid. • Box Lid (Runner Balance). 3. Compare the filling results between the two analyses. Finishing up If the balance results are acceptable, possibly the runner dimensions can be rounded. Any changes in runner diameter from the optimum will influence the balance. If the sized runners are close to a standard size, rounding may be acceptable. Any rounding that is done should be validated using a Fill + Pack analysis to check the balance but also volumetric shrinkage. 24 Chapter 2 Competency check - Family Tools 1. What is the ideal scenario when creating family molds, with regards to part volume? 2. List the main steps to optimize a family mold 3. How does the procedure to analyze family molds differ from analyzing multi-cavity tools? Practice - Family Tools 25 26 Chapter 2 3) Add all the parts to one study file and create the runner system. 2) Run a Fill analysis to verify the process settings.Family Tools 1. 3. How does the procedure to analyze family molds differ from analyzing multi-cavity tools? • There are multiple parts of different volumes and pressures to fill. the balance becomes difficult and the molding window gets small. the molding window may get quite small. with regards to part volume? • The volume of the parts in the family tool should be close together. 4) Balance the runners with the runner balance analysis. List the main steps to optimize a family mold • Moldflow recommends following the steps listed below: 1) Use the Molding Window analysis to find the same processing conditions that works for each one of the parts. optimize the part filling and find the volumes of the parts. Practice . What is the ideal scenario when creating family molds. When the variation in part size becomes large. 2. When one part is many times larger than another. There must be one set of processing conditions found that fills each one of the parts.Family Tools 27 . manually or a combination.Evaluation Sheet . 28 Chapter 2 . the flow length and pressure drop and volume from each gate is about the same. Finally multiple gates can be used to move weld lines. There are two types of problems related to multiple gates: symmetrical and nonsymmetrical part geometries. In this chapter you will also learn how to work with clamp tonnage. Overview In this chapter. pressure and flow length is not the same.CHAPTER 3 Multiple Gates Aim The aim of this chapter is to determine the optimum number and location of gates to make the part fill evenly and with an acceptable pressure. This chapter will use the Molding Window analysis and the fast analysis as an aid for solving the problem. With non-symmetric gate locations. you will look at the issues involved with using multiple gates on parts. With a symmetrical gating location. In both cases. Why do it Two or more gates per cavity are sometimes required for large products where the flow distances from a single gate would be too long. or one gate cannot produce a balanced filling pattern. Multiple Gates 29 . the runners need to be balanced by changing the runner diameter to provide the correct volume to each gate so the filling pattern will be balanced. the flow length. 30 Chapter 3 . Practice . You must determine the gate locations and construct and balance the runners. has three gates on the front face of the part. or chest of drawers. Do the others as time permits. You will have a clamp tonnage limitation for this part as well.Multiple Gates This chapter has several models that are used for practice and are described below. Practice .Multiple Gates 31 . The main objective is to balance the hot runners to fill the part with a balanced filling pattern. Door panel: starts on page 45 The door panel will require multiple gates. Table 3: Models used for molding window analysis Description Model Drawer: starts on page 33 The drawer model. The gate locations are fixed. Proceed with the model of your choice. 32 Chapter 3 . Practice . The material is a high-density polyethylene.Drawer Model Design criteria The drawer will be made with a 2-plate tool using a hot runner system. Project setup To open a project 1. Click (File ¨ Open Project) and navigate to the folder My AMI 2010 Projects\AMI Standard 1\Multiple_Gates. You will determine the optimum processing conditions. Figure 6 indicates the position of the gates. size. • Review filling results. • Create a hot runner system using the runner creation wizard. • Run a filling analysis at the optimum processing conditions. Figure 6: Drawer with injection locations For the drawer model. Double click the project file Multiple_Gates. • Change drop diameters to improve the balance as necessary.Multiple Gates 33 . • Run a fill analysis with the runners. you will perform the following: • Run a molding window analysis with the provided gate locations. • Re-run and review results. 2. • Evaluate flow balance.mpi. and balance the hot drops accordingly. 2. Follow the General Interpretation Procedure below to interpret the results and determine your processing conditions. Click (Start Analysis). 7.3. 3. Maximum rise to 2ºC. Double click (Analysis ¨ Process Settings).2. 3. the import dialog will open in the project directory. 3. To review the model 1. 3. 3.1. Click the Edit button in the Injection molding machine frame. h Set the Pressure factor to 0. Select the material BASF. Click the Advanced options button. 3. Record the processing conditions you choose in Table 4 on page 40.3. Polystyrol 165 H. h Set the Flow front temp. Click File ¨ Preferences. Click 5. 3. 3. 4. (Analysis ¨ Set Analysis Sequence) and select Molding 2. 2. h Set the maximum machine injection pressure to 140 MPa. Ensure the active units are set to metric units. Investigate the model geometry using the model manipulation tools. h Click OK to exit Advanced options. Ensure the Default to project directory box is checked. 34 Chapter 3 . Click OK to exit the Process Settings Wizard. Click on the Directories tab. Determine molding conditions To analyze the molding window 1.3.1.8 in the Feasible molding window. Open the model Drawer. h Click OK to exit the dialog. Double-click Window. • By having the box checked. Turn on the default layer to see the injection locations. h Click the Hydraulic Unit tab.5 in the Preferred molding window h Set the Flow front temp. (File ¨ Save Study). 6. Maximum drop to 20ºC. h Set the Pressure factor to 0. 0 C Injection time range to analyze = Automatic Limits for calculation of feasible molding window Shear rate limit = Off Shear stress limit = Off Flow front temperature drop limit = Off Flow front temperature rise limit = Off Injection pressure limit factor = 0.. recalculating mesh match and thickness information Processing Dual Domain mesh.00 Shear stress limit factor = 1.2. Computing match using the maximal-sphere algorithm .00 C Injection pressure limit factor = 0. h If not. Find the recommended processing conditions near the bottom of the Analysis Log.22 tonne Maximum Design Injection Pressure : 180.88 s Figure 7: Molding window Analysis Log Practice .. View the Analysis Log... 1.80 Maximum Design Clamp Force 7000.0 C Melt temperature range to analyze = Automatic from melt temperature = 270. h The recommended conditions should preferably be near the middle of the ranges.. The basic procedure is as follows: 1.00 C Flow front temperature rise limit = 2.4612 s Execution time Analysis commenced at Analysis completed at CPU time used Wed Jul 09 09:15:31 2008 Wed Jul 09 09:15:35 2008 3.1.67 C Recommended Melt Temperature : 295.00 C Recommended Injection Time : 0.0 C to mold temperature = 95. 1.00 MPa Recommended Mold Temperature : 91.00 Flow front temperature drop limit = 20..80 Clamp force limit = Off Limits for calculation of preferred molding window Shear rate limit factor = 1.50 Clamp force limit factor = 0.Multiple Gates 35 . Analysis commenced at Wed Jul 09 09:15:31 2008 Analysis has detected a mesh change since initial mesh generation .Molding window general interpretation procedure The procedure for looking at molding window results will vary. depending on the objectives of the analysis. finished processing Dual Domain mesh Mold temperature range to analyze = Automatic from mold temperature = 80. this would indicate you might need to investigate choosing conditions other than the recommended conditions. Compare the recommended conditions of mold and melt temperature to the ranges near the top of the Analysis log. as shown in Figure 7.0 C to melt temperature = 295. represents an area that is within the preferred molding window. h Red indicates the pressure is higher than the factor set for the feasible molding window. The best cut axis is mold temperature. View the Molding window 2D Slice Plot. This would mean that one of the parameters of the preferred window is outside the limit. • The molding window plot shows a 2D shaded graph.represents the size of the feasible molding window. More than likely it is a temperature limit. Figure 8: Molding window plot showing the size of the molding window 36 Chapter 3 . as shown in Figure 8.2. h Yellow . Two of the 3 variables form the axis of the graph. and the Y-axis is injection time. Hold the left mouse button down and drag the mouse up and down. • The molding window plot will give you a sense for the size of the molding window. the X-axis is melt temperature. The plot uses 3 colors: h Green . the other is the Cut axis for the graph. When the cut axis is mold temperature. It uses mold temperature. • The cut axis can be animated with (Add XY Curve). melt temperature and injection time. Use the examine result tool to find the optimum injection time on the pressure curve.000 psi) guideline. 2. as the mold temperature goes up. h Decide on the mold temperature. melt temperature. See Figure 10 on page 38. and Advanced options settings. Use (Examine result) on the molding window plot to find the injection time and melt temperature found in the analysis log. 3.1. 3. If not. If there is little change in the size of the molding window. h Generally. 3. 2.2.3. 3. a midrange mold temperature can be used.Multiple Gates 37 .4. h Most of the time the mold temperature specified in the analysis log file is near the high end of the range.2. Set the mold temperature cut axis value to the mold temperature you want to use.1. the green area of the zone plot will be under half of the machine’s pressure capacity Practice . Check the Pressure drop. use the examine result tool to find the melt temperature and injection time that are near the size of the molding window. 3 The molding window plot is most meaningful if the machine pressure capacity is known and the pressure factors for the feasible and preferred windows are set. Make sure the pressure is under the 70 MPa (10. Use (Add XY Curve) to animate the molding window plot. 2.3. and injection time that you want to use. These will be the optimum conditions. using the plot properties. slide the optimum mold and melt temperature to the values determined in the molding window plot. the chosen conditions are near the middle of a large preferred window. h This represents the pressure required for the optimum conditions. shown in Figure 9. h Ideally. Determine how much the mold temperature influences the size of the molding window. or about half the machine injection capacity. You will look at other results at these conditions to confirm you like the optimum conditions or if you would like to modify them.2. With the proper molding machine settings. Set the X-axis to be injection time. the size of the molding window increases but typically not by much. Set the cut axis to Mold temperature in the plot properties. maximum (molding window) XY Plot. 4.2. using the plot properties slide the mold and melt temperature to the optimum conditions. Chapter 3 .plot properties Figure 10: Pressure drop XY graph 4. minimum (molding window) XY Plot. Use the examine results tool to find the optimum injection time.1. Set the X-axis to be injection time. Check the Temperature at flow front. explore solution space . h 38 The best injection time will be when the flow front temperature is about equal to the melt temperature.Figure 9: Molding window. 4. Plot in each of the windows a different XY graph.Multiple Gates 39 . (18º F). 10º C. h A 10º C (18º F) drop in temperature in most cases is a very acceptable amount of drop. See Figure 11 on page 39 h A 0º C drop in temperature defines the highest quality. h The lower the shear stress. check the Lock all molding window XY plots in this study box.2. Practice . h A 20º C (36º F) defines the limit of the preferred molding window. If the shear stress is near or above the limit for this plot. h Finding at what times these temperatures occur will give you another way to get a sense for the size of the molding window as the flow front temperature is generally the limiting factor in the molding window. On the Explore Solution Space –XY Plot dialog. (36º F) below the melt temperature. all windows will update accordantly. Check the Maximum Shear Stress XY Plot. You should find that the majority of the part has acceptable levels of stress and there may be some limited areas of high stress. h Typically. Split the screen into 2 or 4 windows. Figure 11: Minimum flow front temperature graph 5.4. open the plot properties.3.1. you should concentrate on the shear stress result when you run a fill or pack analysis. Use the examine results tool to find where the temperature is 0º C. Set the X-axis to be injection time. 5. and 20º C. Make sure the shear stress is below the material limit. Now as you manipulate the sliders. using the plot properties. the better. assuming it was set a maximum temperature drop of 20ºC (36ºF) in the advanced options. 5. the maximum shear stress plotted in this result will be significantly higher than the nominal shear stress in the part. For one of the graphs. and slide the mold and melt temperature to the new conditions. / Up to four XY plots can be viewed and manipulated at the same time. 1. There may be some very local areas where the shear rate approaches the limit. 3.8 and 0. The maximum quality possible is 1. but the Molding window 2D Slice plot is the best plot to determine the optimum conditions and then use others to confirm the conditions. To view the quality plot: 1. found in the analysis log. View the quality plot and set the X-axis of the graph to be injection time using the plot properties. The quality plot The molding window analysis determines the recommended processing conditions. Adjust the mold and melt temperature sliders to the recommended mold and melt temperatures found in the Analysis Log. the data point with the highest quality is easy to visualize. as indicated in Figure 9 on page 38. It will be the recommended injection time in the log file. 6. Use the Examine results tool to find the injection time of the data point with the highest quality. Check remaining plots. Mold temperature generally has the greatest influence so that should be the X axis. The quality is calculated using the parameters in the advanced options described earlier. 6. as there is a sharp drop in quality from the maximum. 2. melt temperature. based on the set of conditions that has the highest quality. and injection time that will have quality values close to the recommended processing conditions. The Molding window plot easily shows this by the size of the green area.95. Plotting the shear rate from a molding window analysis will show you how the shear rate drops with the increase of the injection time. There will be many combinations of mold temperature.6. It is useful to view the quality plot to understand how the recommended conditions are picked. Generally the maximum values for a given part are between 0. Table 4: Drawer Processing Conditions used Parameter Value Mold Temperature Melt Temperature Injection Time Run the first fill analysis This is to verify the processing conditions used when the runner system is added. Shear Rate h The shear rate will never be excessive in your part as a whole. 40 Chapter 3 . • Normally. Cooling time h The cooling time is viewed to see what effect processing conditions have on the cooling time.2.0. To create a hot runner 1. Click Modeling ¨ Runner System Wizard. for the position of the sprue. 4. for the location of the manifold per the drawing in Figure 13. • Make sure the pressure is less than 70 MPa. Click (File ¨ Save Study as) and name the study Drawer fill. Check the Bulk Temperature. 5. Click the I would like to use a hot runner system box. 3. Set the gate size per the drawing in Figure 12. 2. 6. 3. Create the hot runner system To prepare for creating the runner system 1. Check other plots as necessary. 4.Multiple Gates 41 . • Ensure the filling is balanced between the 3 gates. 4. 5. Double-click (Start Analysis!). Click (File ¨ Save Study). • Make sure the shear stress is not too high. 2. runner and drop sizes per the drawing in Figure 13. 2. Set the analysis sequence to Fill. Change some inputs and re-run the analysis if you are not satisfied with the results. 3. To run a filling analysis 1. Plot the Fill time plot. • The range of temperatures should be less than 20º C. 6. Practice . To review the results 1. Click (File ¨ Save Study as) and name the study DrawerRun1. Set the sprue. 2. Check the Pressure at V/P Switchover. Select Center of gates. Enter the process settings that you determined from the molding window analysis. Set the Top runner plane Z. Check the Shear stress at wall plot. Open Plot properties. 42 Chapter 3 . Click (Start Analysis). Plot Fill time. Ensure the process settings are correct. 1. Change the Method to Contour. To review the results 1.1. 3. 1.2.Figure 12: Drawer gate detail Figure 13: Drawer drawing To run a fill analysis with the runners (File ¨ Save Study). Click 2. 1. The top is also filling faster than the bottom.2. If prompted. 4.3. Click (File ¨ Save Study). 6. Refer to Figure 14.4. If prompted. Plot Pressure at V/P Switchover.1. (Start Analysis). h A diameter of 7. Click (File ¨ Save Study as) and name the study DrawerRun2. h Change the name to 7 mm drop. select Beam element as the entity type and click OK.0 mm.1.5. 5. This is an indication that the balance could be better.0 mm. Click New. To revise the results 1. 3. 5. 3. Select the elements in the top drop.2. h A diameter of 5. 4. Select Hot runner to create a new hot runner property with: h A non-tapered circular shape. h Change the name to 5 mm drop. Change the center drop.6. Click (File ¨ Save Study).Multiple Gates 43 . Refer to Figure 14. • Notice how the center of the sides has filled out.4. Click New. The size of the top drop will be reduced to 7 mm and the center drop will be reduced to 5 mm to help create a better balance. Click (Edit ¨ Assign Property). Click (Bottom View) 4. 4. select Beam element as the entity type and click OK.3. 4. 5. Click 7. Decide if you think the filling is balanced enough. Create a new hot runner property with: h A non-tapered circular shape. Select Hot runner to create a new hot runner property with: 5. 4. 5. 5. Select all of the elements in the center drop.2. Practice . Change the top drop. Click (Edit ¨ Assign Property). The center is filling too fast.5. 5. 2. and the areas left to fill are on the outside corners. change the selection to Contour. 1. and tile the results to compare them if desired.2. the wall thickness on the part will need to be adjusted. Also the bottom could be increased in thickness slightly to encourage flow in that direction. To further improve the balance.3. Click (Plot properties). Plot the Pressure at V/P Switchover.Top drop Center drop Bottom drop Figure 14: Drawer drop locations To review the results 1. Summary Reducing the center and top drops made the balance a bit better. • Now you can see that the balance is better. On the Methods tab. 2. Open the DrawerRun1 study. The top of the part needs a flow deflector so the center of the top does not fill out so early. Plot the Fill time plot. • The Switchover is just early enough to see that the part is a bit more balanced. 1. 1.1. 44 Chapter 3 . Figure 15: Door panel model PL Underside Figure 16: Door panel side view Practice . • There must be no air traps in areas that are difficult or impossible to vent. • The number and location of gates. plus the processing conditions are to be determined. • There should be as few weld lines as possible. The tool is constructed with the underside of the part on the cavity side of the tool so it can be gated on that side. • The tool will go in a 1500 tonne press.Multiple Gates 45 . The design clamp limit will be 1200 tonnes or 80% of the press’ capacity.Door Panel Design Criteria The door panel is constructed with a 2-plate tool using a hot runner system. The tool will have cavity side ejection. • The hot runner system must be sized and balanced so the filling pattern from the gate locations is balanced. • Evaluate the filling. 3. 46 Chapter 3 .Analysis procedure For the door panel model you will perform the following: • Iterate between the gate location analysis and molding window analysis to determine the number and general location of the gates. The clamp tonnage limit must be set for the initial study so all studies created after this point will have the correct clamp tonnage. • Run a fill analysis with the runners. Ensure the Default to project directory box is checked. Click File ¨ Preferences.3. in order to keep the fill pressure below 50% of the machine’s capacity. 2. Click the Advanced Options button. the import dialog will open in the project directory. 3. Click on the Directories tab. 3.mpi.2. Open the model Door Panel. 3. Double click the project file Multiple_Gates. 3.1. To review the model 1. • Review filling results. • Revise the gate location(s) as necessary to get a good balanced filling pattern within the 1200 tonne clamp tonnage design limit. To set the clamp tonnage limit 1. Investigate the model geometry using the model manipulation tools. 2. • Change drop diameters in to improve balance as necessary. Ensure the active units are set to metric units. Click (File ¨ Open Project) and navigate to the folder My AMI 2010 Projects\AMI Standard 1\Multiple_Gates. • Create a hot runner system using the chosen gate locations. • By having the box checked. • Run a filling analysis at the optimum processing conditions and gate locations determined. Click the Edit button next to the Injection molding machine box. • Re-run and review results. 2. Project setup To open a project 1. Click the Process Setting Wizard. 2. Click the Flow resistance indicator result. 5.Multiple Gates 47 . 6. 7. Click the Clamping Unit tab. 5. an ABS from Sumitomo Chemical Company. Enter 1200 in the Maximum machine clamp force field.4. 4. • Notice how the gate location is near the arm rest. (Analysis ¨ Set Analysis Sequence) and select Molding Practice . Click (File ¨ Save Study). Select the material Kralastic SXB-367. 6. 8. but you have no idea what this pressure is. The analysis calculates the location to minimize the pressure. Click to run the analysis. The gate location(s) for the door panel can be anywhere on the underside of the door panel. To view the gate location results 1. To run a molding window analysis at the chosen gate location 1. Right-click on the study Door Panel Gate Loc 1(Gate Location). To run an initial gate location analysis 1. Set the analysis sequence to Gate Location. Ensure the Do not exceed maximum clamp force box is checked. Select Rename and enter Door Panel Gate Loc 1 MW. 2. Selecting gate locations and molding conditions Using the gate location analysis is a good way to get started for determining the gate location for the door panel. Click OK 3 times to get out of the dialogs. Click and ensure the Advanced gate locator is used and the number of gates is set to one. Click (File ¨ Save Study as) as Door Panel Gate Loc 1. 3. Click OK to exit the wizard. 3. Double-click Window. Click the Edit button in the Injection molding machine frame. h Click OK to exit the dialog. 4. Table 5: Truck Panel Initial Processing Conditions Parameter Value Mold Temperature Melt Temperature Injection Time Optimize the filling Now that the gate location(s) and molding conditions have been found you need to run a fill analysis to see how the part actually fills and what the clamp force is. Maximum rise to 2ºC. 4. You can pick your own gate locations. h Click the Hydraulic Unit tab. Click 6. h Set the Pressure factor to 0. 4. h Set the Pressure factor to 0.8 in the Feasible molding window. h Set the maximum machine injection pressure to 140 MPa.4.5 in the Preferred molding window h Set the Flow front temp.1. 7. Click the Advanced options button. h Click OK to exit Advanced options. Follow the Molding window general interpretation procedure on page 35 to interpret the results and determine your processing conditions. or use the gate location analysis to help you pick more gates. 5. revise the gate location(s) and re-run the analysis. there will be no molding window and an warning message indicating there is none. / In extreme cases. (File ¨ Save Study). The cause of the error would be the pressure or clamp force being too high. If you don’t like the molding window results. Click OK to exit the Process Settings Wizard. Click (Start Analysis).3. • The molding window analysis does not output any results that indicate clamp force changes with processing conditions. The pressure to fill must be lowered by reducing the maximum flow length by moving the gate or adding gates. 9. h Set the Flow front temp.2. 48 Chapter 3 . if the pressure to fill is limited. Maximum drop to 20ºC. Record the processing conditions you select in Table 5. 8. However. so will the clamp force. Double click (Process Settings). Ensure the clamp force is set to 1200 tonnes.4. Click the Intermediate Output tab. 6. 6.3. h This script intermediate results at specific times during the filling and packing phases.7. 6. Double click (Process settings wizard).1.2. Enter the process settings that you determined from the Molding Window Analysis. 7. Close the editor when done reviewing the script. 3. 5. and the times are set as they were in the vbs script. Click Tools ¨ Play macro (optional). 3.1. Click OK. 6. 3. 6. Select Edit to open the script in a text editor. 3. Click Open to play the script and define the intermediate results.Multiple Gates 49 . 6. Double-click (Start Analysis). 3. 2. Click OK on the Process Setting Wizard dialog. Click Advanced options.6. Ensure the filling phase and packing phase regular results have Write at specified times selected. Click Edit in the Solver parameters frame. 6.5. Highlight the script MP Intermediate results defining. h If you can’t find the script. Practice . 3.vbs. Ensure the Door Panel MW1 is active and click name it to Door Panel Fill 1. 8. Click Edit in the Injection molding machine frame. To run a filling analysis 1. ask your instructor about it. Navigate to the My AMI 2010 Projects\scripts folder.2 seconds during filling and 1 second during packing. Double-click (File ¨ Save Study as) and and set the analysis sequence to Fill. The full list of result times was omitted to save space.8.2.4. 6. A portion of the script is shown in Figure 17.5. Exit from advanced options. at 0. Click the Clamping Unit tab. 4.3. 6. 10005 =DD Set DVec = Synergy.1.AddDouble 0 Prop.CommitChanges "Process Conditions" Figure 17: Example vbs script for setting the intermediate results To review the results 1. Open the Analysis Log and view the filling phase results table. Chapter 3 .2 DVec. write results 2 = specified times PropEd. • See Figure 18 as an example. 2. h 50 The clamp force limit was reached so early. Animate the result to time closest to the time when the clamp force was reached.PropertyEditor() Set Prop = PropEd. DVec.CreateDoubleArray() DVec. DVec '198 = filling phase.6 DVec.FindProperty(10000. DVec '180 = Write filling phase regular results at times Set DVec = Synergy.AddDouble 0 Prop. the later the better.CreateDoubleArray() DVec.CreateDoubleArray() DVec.AddDouble 2 DVec. DVec.Set Synergy = CreateObject("synergy. Animate the result to time step closest to the time when the clamp force was reached. the clamp tonnage should not be reached. DVec ' 199 = Packing phase.AddDouble 4. h There is a significant amount of the part yet to fill when the clamp force was reached.FieldValues 182. 1) '10000 = midplane. DVec '182 = Write Packing phase regular results at times Set DVec = Synergy.AddDouble 2 DVec. If it is.FieldValues 199. • This will show when the clamp tonnage limit was reached and how the pressure and flow rate changed because of the clamp tonnage limit. Plot Pressure.Synergy") Synergy.AddDouble 25 Prop. Display Fill time. • Preferably.8 DVec.AddDouble 5 Prop. write results 2 = specified times Set DVec = Synergy.FieldValues 198. 2. there is not much overpacking.AddDouble 6 DVec. 3.AddDouble 8 .4 . .AddDouble 4.AddDouble 7 DVec.AddDouble 0.FieldValues 180. 3.SetUnits "Metric" Set PropEd = Synergy.CreateDoubleArray() DVec. .AddDouble 0.1. 78 | 590.80 | 41.76 | 1200.85 | V | ** WARNING 98932 ** The clamp force required to fill/pack the part is greater than the maximum machine clamp force value in the clamping unit properties of the currently selected injection molding machine.10 | 93.89 | V | | 4.00 | 393.00 | 46.07 | 1200.Multiple Gates 51 .79 | 1200.38 | 8.68 | V | | 3.33 | 1200.00 | 608.78 | V | | 2.80 | 88.60 | 84.84 | 607.40 | 4.00 | 22.19 | 37.69 | V | | 3.00 | 310.92 | 577.54 | 32.77 | 1200.46 | 262.38 | 1200.67 | V | | 3.96 | 39..70 | 1200.40 | 31.43 | 35.72 | 99.19 | 603.58 | 601.42 | 605.59 | 1200.80 | 97.85 | 36.96 | 607.90 | V | | 1.00 | 133.14 | 47.46 | 17.92 | V | | 3.87 | 45.00 | 73.04 | 565.60 | 60.66 | 33.20 | 27.20 | 50.92 | 603. The maximum machine clamp force will be maintained in the analysis.20 | 94.37 | V | | 4. ----------------------------------------------------------------------- Figure 18: Analysis log filling phase table Practice .68 | 72.17 | 592.52 | 1020.16 | V | | 0.07 | V | | 3.90 | 90.78 | 629.63 | 325.00 | 92.71 | 393.28 | 748.37 | 27.40 | 95.13 | V | | 5. The clamp force of the injection molding machine is insufficient.01 | 28.78 | 601.58 | 25.25 | V | | 5.14 | 29.53 | V | | 1.80 | 50.00 | V | | 4.79 | 546.69 | 595.28 | V | | 0.60 | 96.00 | 205.20 | 74.05 | 32.00 | 234.87 | 877..39 | 207.20 | 3.00 | 12.42 | 44.80 | 17.29 | V | | 0.Fill Analysis Residual Stress Analysis analysis is beginning .74 | V | | 1.94 | 1200.00 | 69.76 | 466.71 | 15.95 | V | | 4.31 | V | | 1.80 | 65.34 | 1200.19 | V | | 2.95 | 597.93 | 98. Filling phase: Status: V = Velocity control P = Pressure control V/P= Velocity/pressure switch-over |-------------------------------------------------------------| | Time | Volume| Pressure | Clamp force|Flow rate|Status | | (s) | (%) | (MPa) | (tonne) |(cm^3/s) | | |-------------------------------------------------------------| | 0.69 | 131.56 | V | | 4.30 | 95.52 | V | | 2.00 | 86.01 | 21.22 | 42.60 | 12. | 3.58 | 167.32 | 40.61 | 29.36 | 604.17 | V | | 2.40 | 605.79 | 23.47 | 32.00 | 65.60 | V/P | ** WARNING 128272 ** Short shot detected.20 | V | | 4.23 | 13.35 | 41.90 | 31.00 | 97.23 | 19.33 | V | | 1.30 | 600.40 | 79.69 | 42.40 | 8..75 | 599.44 | 47.50 | V | | 4.40 | 55.00 | 266.60 | 36.12 | V | | 2.00 | 27.11 | 588.25 | 1200.16 | 40. Ensure the same intermediate results files are selected. Looking at the fill time and pressure plots you can see that a significant area of the part is at high pressure.1.4. the fill time will probably be shorter than with one gate. Additional gates must be used. 6. To determine the final gate locations (File ¨ Save All Studies). 3. Click 2. 6. causing the spike in clamp force.Results interpretation It is clear just from the analysis log that the single gate option will not work. h The fewer gates the better. Large areas of high pressure contribute to a spike in clamp force. • With a shorter flow length. The clamp force limit was hit early and a short shot was created. Compare the new results with the first filling analysis. molding window analysis and fill analysis to find and test gate locations.4. 5. 3. Review the results. h Ensure the gate locations determined by the gate location analysis are possible with a hot runner. 1.1. Decide if the results are reasonable or they still need adjusting. Use the number of gate of your choosing. Run a fill analysis. (File ¨ Save Study as) and 3. Look carefully at the pressure plot. 6. 5. 4. Set the analysis sequence to Gate Location. 6. 3.2.3.1.2.2. Review the gate location results. 5. Move the gates if necessary to make it possible to use the locations. Iterate between the gate location analysis. Activate the Door Panel Fill 1 study and click name it Door Panel Gate Loc 2. 52 Chapter 3 .3. Ensure the gate locations you pick are possible when using a hot runner system on the underside of the part. This will indicate how well balanced the filling is. Finalizing the gate locations A single gate will not work because the clamp force is too high. Lock the results and tile the windows to look at the results together. 3. Run a Molding window analysis with the new gate locations. Run a gate location analysis. 6. Use the new gate locations and molding conditions determined. Try to make them better. • Add a gate. The fill time was set with 20 frames. The plot below shows the position of the flow front with 4 subtle variations in the gate location. • Decrease the injection time. the camp force is exceeded. • Use the recommended ram speed profile. / Don’t stop at one analysis even if you think the results are good. showing the current frame only. the scale was 0 to 4 sec. To get this plot. or filled later. • Move gate(s) closer to areas that did not fill. In all cases. The weld line locations also change.. For instance.Multiple Gates 53 .7.2 sec. Practice . • Increase the melt temperature. a slight variation in gate location can make a large difference in the filling pattern and clamp force requirements. Consider one or more of the following changes as needed to get acceptable results. making the increment 0. and banded color was on. but at different times and with different reductions in flow rate. 2. 2 1 Sprue 4 Drops A B 3 Figure 19: Manifold curves The task below steps through the process of fixing the manifold for the gate locations above. Click Next. 4. On page two of the wizard. On page one of the wizard. / Make the manifold diameter larger than the drops. Enter the size of your choosing for the runner (manifold). Enter the diameters and length of your choosing for the Gates. Click Finish to complete the runner system. The hot manifold created by the wizard may not be practical. Enter 25 mm as the sprue length. 4. The manifold has extra 90º bends in it going from the sprue to the drops. enter: 3. On page three of the wizard. 3. In Figure 19A.1. Check the I would like to use a hot runner system box. Click (File ¨ Save Study as) on the study with the gate location and processing conditions you like. Click Modeling ¨ Runner System Wizard to create the hot runner. Enter the size of your choosing for the drop.3. 5. 54 Chapter 3 . the manifold design is not practical.3. Enter 0 degrees for the included angle. enter: 5. 4. 3. The manifold would be built more like Figure 19B.4.2.4. Enter 400 mm as the top runner plane. 4. 3. Click Next.Design and analyze the feed system To create a hot runner 1. Use these steps to fix your manifold system as needed.6. 3.5. The manifold goes straight between the drops. 4. A manifold like this would not be built.1. as a new name such as Door Panel Run 1. 4. 2. Enter 12 mm as the sprue diameter. 5.2.1. enter: 4. Select Center of Mold for placement of the gates. Consider replacing it. 2. Select the node at the end of drop 3 for the Second field. 5. Click Create line in the Create curves tools in the toolbox. 4.3. 2. 2. Click OK to accept the entity selection. Rename element properties: 1.Multiple Gates 55 . 2. Select the node at the end of drop 2 as shown in Figure 19B for the First field. h Ensure the box Apply to all entities that share this property is checked. Select Beam element and Curve as the entity types. Click Purge Node in the Nodal mesh tools . 2. 5.7.1. Right-click and select Properties.2.5.1. Click Apply. in the toolbox. Select the Manifold you renamed property. Click OK.2.1. 1. for the Second field.5. 3. Click Apply. 4. Press the Delete key to delete the elements and curves. 1. Change the property name to Manifold XX mm. Click Edit ¨ Select by ¨ Properties or CTRL + B. 3. Enter 3 in the Number of nodes field. 2.8.3. To revise the runner layout 1. 5. Select the node at the end of drop 1 as shown in Figure 19B for the First field. 4. Set the filter to Node.2. where XX is the diameter of it.1. h The new name will easily identify this property in the property lists.6. 5.3. 3.3. 3. Create a curve between drop 1 and the curve between drops 2 and 3. Click Nodes by Dividing Curve in the Create Nodes tools in the toolbox. Create a curve for the manifold between drops 2 and 3.2. Click Create line in the Create curves tools in the toolbox.4. Delete the elements. 3. 2. Select the node at the center of the curve going between drops 2 and 3.1. Click Apply. Practice .4. 4. 5.4.3. Select the curve between drop 2 and 3 just created. 3. Highlight one of the elements in the manifold. 2. Click Apply. 2. 2. 1. Click Close. 6. Click Apply. 6. Select the node at location 4 as shown in Figure 19B for the Second field.6.9. 6. curve and LCS not needed. 7.6.3.Click the Relative radio button.1. Break and delete the curves. Click Close.Click Apply. 9.4.8. 6. 6.Select the node at the base of the sprue for the First field.14. Apply the Manifold property to the new curves. 7. Click on the 2 curves shown as break 2 in Figure 20. 8. 6. Select the node at the base of the sprue for the Third field. Activate the Runner System layer. 7.15. 7. 6. 6.11. 6. Select the node at the end of drop 1 as shown in Figure 19B for the First field. Select and delete the node. Set the filter to Node.13.Right-click select Activate as LCS. 6.5. Click on the 2 curves shown as break 1 in Figure 20.Inter 0 -200 in the Second field. Click Apply. 7. 6. 7. 6. 7. Click Apply.4.2.5. • Make sure the Runner layer is active and place the new mesh on the active layer.12.10. 6. 6. 6.6. Click Modeling ¨ Local Coordinate System/modeling plane ¨ Define. Select the new LCS.7. Click Break Curve in the Create curves tools in the toolbox.2. Mesh the new curves at the same density as the drops.3. 7.Click Create line in the Create curves tools in the toolbox. Make a LCS to help construct the runners. Break 1 Break 2 Delete Figure 20: Manifold curve construction 56 Chapter 3 .7. Some prefer to change the manifold. Either part of the manifold or drops can be changed to fix the problem. 4. 3. and you will need to make this decision. 2. • Make sure the balance is acceptable. 2. Make changes as necessary to improve the balance or to fix some other problem. • Are they still in acceptable locations? 4.Multiple Gates 57 . the sizes and layout of the hot runner system needs to be adjusted. View the Fill time plot. Run the fill analysis with the same conditions as the study without the runners. Look at the revised results. 3. To check the balance 1. View the Weld lines and Air traps. others the drops when there is a choice. • When is the limit reached? • Does the velocity profile change much? 5. Repeat as necessary to get a good result. View the Analysis Log and check for the clamp force limit. 5. To re-run the analysis 1. Click (File ¨ Save Study as) with a new name. View the Pressure. Practice . • Is the pressure distribution acceptable? If the results are not as balanced as they are in the study without the manifold. Re-run the analysis. Different philosophies exist on what to change. 58 Chapter 3 . What are the types of multiple gates scenarios that you may have in the part geometry? 2. How to identify a non-symmetrical multiple gate scenario? 4.Competency check . How do you identify a symmetrical multiple gate scenario? 3. What are the types of analyses recommended by Moldflow to use to aid in the multiple gates optimization process? Practice .Multiple Gates 59 .Multiple Gates 1. 60 Chapter 3 . 2. Practice . Then the runner system should be added balanced and further filling and packing analyses should be run to finalize the filling of the part. 4. How do you identify a symmetrical multiple gate scenario? • The part will have symmetrical gate locations. 3.Multiple Gates 61 .Multiple Gates 1.Evaluation Sheet . What are the types of multiple gates scenarios that you may have in the part geometry? • It can be either symmetrical or non-symmetrical part geometries. How to identify a non-symmetrical multiple gate scenario? • The part will not have symmetrical gate locations. therefore it is more difficult to optimize. And the flow length and pressure drop from each gate will be about the same. What are the types of analyses recommended by Moldflow to use to aid in the multiple gates optimization process? • The user should run a set of molding window analysis and fast filling analysis to aid in the number and location of the gates on the part. And the flow length and pressure drop from each gate will not be the same. 62 Chapter 3 . the filling and cooling of the part filling should be optimized first. From this information. therefore.CHAPTER 4 Packing Optimization Aim The aim of this chapter is to learn how to produce a uniform volumetric shrinkage through a part with the use of a packing profile. the likelihood of warpage is reduced. Packing Optimization 63 . and can be used with a midplane mesh as well. This technique will be demonstrated on Dual Domain and 3D models. Why do it When there is a uniform volumetric shrinkage across the part. therefore. an initial packing profile is produced. Warpage is simply caused by a variation in shrinkage. Packing is influenced by the way a part is cooled. so is the warpage. and then modified as necessary to produce the desired results. Overview To create a packing profile. An initial constant packing profile is run. The volumetric shrinkage distribution should be as small as possible. when the shrinkage variation is reduced. it is best to produce the packing profile based on cooling results. 64 Chapter 4 . Practice - Packing Optimization This chapter has two models that are used for practice and are described below. One is a Dual Domain model the other is 3D. Do the practice for the model of the mesh type you use most. Do the other as time permits. Table 6: Models used for packing optimization Description Model Snap Cover: starts on page 67 This part uses a Dual Domain mesh. Use this part if your primary mesh type you use is Dual Domain or midplane. Snap Cover3: starts on page 85 This part uses a 3D tetrahedral mesh. Use this part if your primary mesh type you use is 3D. Practice - Packing Optimization 65 66 Chapter 4 Snap cover with a Dual Domain mesh Design criteria The packing profile for the snap cover must be optimized. The cooling analysis has already been done. The initial processing conditions and criterion are shown in Table 7. Determine a packing profile to minimize the volumetric shrinkage. Review the results on the initial packing analysis and make modifications to the profile will reduce the volumetric shrinkage. Table 7: Snap cover parameters Parameter Value Model Type Dual Domain Material Maplen EP301K (PP) Mold Temperature 25º C Melt Temperature 220º C Injection + Cooling + Packing 15 seconds Injection Time 1.0 second Initial Packing Pressure 100 % fill pressure Initial Packing Time 9 seconds Target Maximum Shrinkage Variation 2% on the body of the part Project setup To open a project 1. Click (File ¨ Open Project), and navigate to the folder My AMI 2010 Projects\AMI Standard 1\Packing_optimization and double click the project file packing_optimization.mpi. 2. Click File ¨ Preferences 2.1. On the General tab, ensure that Active Units are set to Metric. 2.2. On the Directories tab, ensure Default to project directory is checked. To review the model 1. Open the study SC Fill. • This study will be used to determine the initial packing pressure. 2. Investigate the model geometry using the model manipulation tools. 3. Turn on and off the layers. • Notice there is several layers for the part itself. These can be used to aid in the interpretation of the results. Practice - Packing Optimization 67 To run a fill analysis 1. Double-click (Select Materials) and pick the material Basell Australia, Moplen EP301K. 2. Double-click 3. Double-click (Process Settings) and enter the parameters shown in Table 8. (Start Analysis). Table 8: Snap cover parameters Parameter Value Mold Temperature 25º C Melt Temperature 220º C Filling control Time, 1 second Velocity/pressure switch-over Automatic Pack/holding control %Filling pressure vs time Packing profile 0 100 10 100 Optimizing a packing profile Developing an optimized packing profile for a part requires the following basic steps: 1. Determine an initial packing pressure. 2. Determine an initial packing time. 3. Run the first packing analysis, with a constant pressure. 4. Review the packing results for: h Volumetric shrinkage. h Pressure. h Frozen layer fraction. 5. Create an initial packing profile based on the results from the first packing analysis. 6. Run the packing analysis with the packing profile. 7. Review the packing results for: h Volumetric shrinkage. h Pressure. h Frozen layer fraction. 8. Revise the packing profile and re-run the results as necessary to reduce the volumetric shrinkage variation. Follow the tasks below to optimize the volumetric shrinkage. 68 Chapter 4 or the result pressure at V/P switch-over result. Record the value in Table 9. 2000 for english units Safety factor to only use 80% of machine capacity If this calculation indicates the maximum pressure to be at or below the fill pressure.1. or pressure. • Figure 21 shows an example of the Analysis Log. • This will be listed in the Analysis Log. If however the calculated pressure is well above the pressure required to fill the part. Review the model details section in the Analysis Log from the SC Fill study and find the total projected area of the part. Therefore. Record the packing pressure as 100% in Table 9.× Unit conversion × 0. The packing pressure in the analysis is 100% of the fill pressure and is a good starting point. it can be rounded to the nearest 1 MPa. the clamp force may be a significant problem and will limit the packing pressure to the value calculated. using above. 3. 2. / The packing pressure can be expressed as a percentage. Practice . 2. To calculate the maximum packing pressure 1. the packing pressure can be any value required to get the volumetric shrinkage distribution required. The maximum packing pressure can be estimated by the formula below: Machine Clamp force limit P max = -------------------------------------------------------------------------. A good starting point is a packing pressure that is 80% to 100% of the filling pressure.8 Total projected area of the shot where: P max = The maximum packing pressure that can be used.1. the packing pressure that can be used for part is not limited by clamp force. This will be the reference pressure for the packing. The calculation assumes a uniform pressure distribution across the part.Determining an initial packing pressure When clamp force is an issue or may be one. 1. Machine clamp force limit Total projected area of the shot Unit conversion 0. • The maximum packing pressure by the calculation is well above the V/P switchover pressure. it is important to calculate the maximum packing pressure that could be used. If a pressure is used. This is a conservative estimate as there will never be a uniform pressure distribution. 4.8 = = = = Tonnes(metric) or tons(US / English units) cm^2 or inches^2 100 for metric units.Packing Optimization 69 . Calculate the maximum packing pressure given the molding machine clamp force listed in Table 9. Find the maximum injection pressure. Record the value in Table 9. Determine the fill time for the analysis SC Fill and record it in Table 10. 3. Open the model SC Flat Prof.8812 5.0000 1.0000 0.0000 1. Double-click (Process Settings) and find the IPC time and record it in Table 10.3148 = 49.Model details : Mesh Type = Dual Domain Mesh match percentage = 89.6 % Reciprocal mesh match percentage Total number of nodes Total number of injection location nodes The injection location node labels are: = 88.3737 cm^3 10. This time should be more than enough to ensure that the gate has frozen with pressure still being applied. 70 Chapter 4 .3737 cm^3 0. The initial packing time is based on the Injection+Packing+Cooling (IPC) time defined in the cooling analysis. 2. Subtract the injection time from the IPC time.1547 2459 17.0000 cm^3 17. To determine the initial packing time 1.0589 cm^3 7.1242 cm^2 Figure 21: Example fill analysis Analysis Log Table 9: Packing pressure calculation data Parameter Value Molding machine clamp force limit 75 tonnes Part projected area Pressure at V/P switchover Maximum packing pressure (Calculated) Packing pressure (used) % Determine an initial packing time The packing is optimized on a part that already has cooling run on it.1 % = 2604 = 1 Total number of elements Number of part elements Number of sprue/runner/gate elements Number of channel elements Number of connector elements Parting plane normal Average aspect ratio of triangle elements Maximum aspect ratio of triangle elements Element number with maximum aspect ratio Minimum aspect ratio of triangle elements Element number with minimum aspect ratio Total volume Volume filled initially Volume to be filled Part volume to be filled Sprue/runner/gate volume to be filled cm^3 Total projected area = = = = = (dx) = (dy) = (dz) = = = = = = = = = = = 4979 5172 5118 51 0 3 0.5040 5241 1. study. Record the value in Table 10. Subtract the fill time from the IPC time and round down to the nearest second. 5. Table 10: Determine the packing time Parameter Value IPC time Fill time Initial packing time (calculated) Run the first packing analysis The first packing analysis is done with a constant packing pressure for a time long enough for the gate to freeze off. 3. Practice .Packing Optimization 71 . The times were primarily set up too have finer increments around the time the gate is freezing. Double-click (Analysis Sequence) and set the sequence to Cool + Fill + Pack. To run the first flow analysis 1.4. Double-click (Process Settings) and enter the parameters shown in Table 11. 2. Activate the SC Flat Prof. 4. Table 11: Snap cover parameters Parameter Value Mold Temperature 25º C Melt Temperature 220º C Mold-open time 5 seconds Injection + packing + Cooling time 15 seconds Filling control Injection time Fill time 1 second Velocity/pressure switch-over Automatic Pack/holding control %Filling pressure vs time Packing profile 0 Pack pressure from Table 9 Pack time from Table 10 Pack pressure from Table 9 3 The study has intermediate results defined by specified times. Double-click (Start Analysis). The shrinkage is rather low at the gate. Click 72 Chapter 4 to add the points if not already active. Volumetric shrinkage interpretation Results are automatically scaled by visible layers which makes it easy to scale results to portions of the model of interest. then OK. 4. 3. The volumetric shrinkage distribution used for optimization should concentrate on the main body of the part. Click 5. the volumetric shrinkage variation across the part should be under 2%. h Gate. Select Volumetric shrinkage from the Available results list. 2. Click on 25 to 30 points on the part from the gate location to the end of the fill as shown in Figure 22. Click Path plot as the plot type. and rather high end of fill. The shrinkage distribution indicates that the gate area is over packed.Review the packing results Volumetric shrinkage as a shaded image To view the Volumetric Shrinkage at ejection results 1. • Watch the scale change as layers are turned off. • Runners. The volumetric shrinkage will NOT be uniform if you consider small detail that is thick or thin. Ensure that only the following layers are turned on: • Body. 3. h Detail. 4. • Gate. Click on Volumetric shrinkage at ejection result. Click off the layers in the following order. Volumetric shrinkage as a path plot A volumetric shrinkage path plot is an excellent way to watch how volumetric shrinkage changes over time. To create volumetric shrinkage path plot results 1. Preferably. (Select) when done to stop picking points to add. • Detail. • Rotate the part so you can see the detail as it is turned off. Click (Results ¨ New Plot). h Runners. 2. Ensure that only the Body layer is turned on. . Figure 22: Path plot locations for volumetric shrinkage 6. Click OK to create the plot. Click (Animate results). the following nodes. the shrinkage is fairly uniform across the part until the part begins to freeze. Volumetric shrinkage path plot interpretation Initially. Then areas closer to the gate begin to drop considerably lower than the areas at the end of fill. 7. 3. 2482. There is about a 10 MPa pressure difference between the gate and end of fill when the end of fill is at its peak pressure. Click (Results ¨ Plot Properties) and set the Y-axis scale from 0 to 10. 6. Enter in the Entity IDs dialog that opens. Pressure results To create an XY plot of pressure 1. 5. Click (Select) to stop picking entities. 2. about 10% but quickly the volumetric shrinkage drops.Packing Optimization 73 . The gate area also has a higher pressure for a much longer time. Click (Results ¨ New Plot). As the shrinkage drops. The others go from near the gate to the end of fill. 4. 2805. Select XY Plot in the Plot type list. the volumetric shrinkage is high.5. Practice . You will create a decayed packing profile to achieve a more uniform volumetric shrinkage. 2709. then press Enter: • 4979. Select Pressure in the Available plot list. This results in the over packing as shown in the volumetric shrinkage results. Pressure XY interpretation Node 4979 is at the top of the sprue and node 2805 is at the end of fill. 3002. The traces of the nodes plotted should be nearly on top of one another during packing to have a uniform volumetric shrinkage. 5. • This defines the constant pressure time.1 seconds. The pressure goes to zero. 4.1. and is based on the pressure trace of node at the end of fill (2805). Record the value in Table 12. Find average time between these two times. 74 Chapter 4 .2. The transition point is defined by a point midway between the time when the pressure is maximum and the time which the pressure reaches zero. as shown in Figure 23.1 seconds. 2. Record the value in Table 12.3. Record the values in Table 12 on page 75. • This average defines the transition point. 3. Open the Analysis Log and locate the V/P switchover time in the filling phase status table. The transition point is between the constant pressure time and the decay time.1. determine the constant pressure time and the decay time.1.1. 4. 3. 2. Record the value in Table 12. The decay will then be linear going to zero when the gate freezes. Subtract the V/P switchover time from the transition point. 4. Round the average to 0.To create the first decayed packing profile. 5. Determine the Decay time The frozen layer fraction is used to calculating the decay time by determining the time when the gate is frozen and subtracting the transition point time. Click the data point at the time for node 2805 when: 2. 3. Click (Examine results). The pressure is at its maximum.2.2. Round it to 0. 2. Transition point Pressure Constant pressure time Decay time Pressure at zero Time Figure 23: Packing profile components To determine the constant pressure time 1. To plot the frozen layer fraction 1. To determine the pack pressure 1. For all subsequent packing analyses. 6. Subtract the transition point from the gate freeze time. Ensure only the Gate and Body layers are on. h The gate and part should have a frozen layer fraction of 1. Click (Step Backward) to animate the result one frame at a time. 3. Record the value in Table 12. 1. the packing pressure is set by packing pressure directly. and uncheck Nodal averaged from the Optional Setting tab.0. 5.Packing Optimization 75 . Round it to nearest 1 MPa. 6. 4.1. which represents gate freeze. Click the Frozen Layer Fraction plot. Table 12: Values for calculating the first injection profile Description Value Time when end of fill node reaches maximum pressure Time when end of fill node at 0 pressure Average between the first two times (Transition point) V/P switchover time Transition point . most if not all the part may have a frozen layer fraction of 1. Open the Analysis Log and locate the Pressure at the end of fill. in the filling phase status table. Record the value in Table 12.1. • The first packing analysis set the packing pressure as a percentage of the fill pressure.2. A long estimate is conservative. Examine the Analysis Log file to determine what that pressure is.1. 5. Record the value in Table 12 as the decay time. 5.0 before the gate. Rotate and zoom up on the gate area so you can see the gate and surrounding area of the part. Use your best judgement to determine at what time the part can no longer be effectively packed. h In some cases when the gate is thicker.V/P switchover time (Constant pressure time) Gate freeze time Practice . in this case 100%. Click (Results ¨ Plot Properties).2. Start at its maximum time and step backwards one step at a time until the gate is just frozen. 2. 1. 3. To run the first flow analysis 1. The pressure is the Packing pressure defined in Table 12. Double-click (Process Settings) and enter the parameters shown in Table 14. 2. Run the second packing analysis The second packing analysis is done with the decayed packing profile defined above. Double-click (Start Analysis). It should look similar to Figure 24. 0 The time duration is the decay time defined in Table 12. The pressure is the same packing pressure used above. Click (File ¨ Save study as) and enter the name SC Prof 1. 4. Table 13: First decayed packing profile Time Duration Pressure Description [Sec] [MPa] 0.2 seconds defined from Table 12.Transition point (Decay time) Packing Pressure Create an initial packing profile Reviewing the results from the packing analysis with a constant profile is used to write the first packing profile. 3. The time duration is the Constant pressure time . This time is used to allow the machine to react to the pressure change. The packing profile is described in Table 13.2 seconds. study. Activate the SC Flat Prof.Table 12: Values for calculating the first injection profile Description Value Gate freeze time . Click the Plot Profile button on the Pack/Holding Control Profile Settings dialog to see the shape of the profile.2 The time duration is 0. This is the time required to go from the V/P switchover to the packing pressure.0.1. Table 14: SC Prof 1 parameters Parameter Value Mold Temperature 60º C Melt Temperature 240º C Mold-open time 5 seconds Injection + packing + Cooling time 21 seconds Filling control Injection time Fill time 1 second 76 Chapter 4 . Rotate the parts to see the variation in shrinkage. 6. Click (Plot ¨ Properties) and set the scale to the range that encompasses both parts. • Note the differences in the ranges. Click Windows ¨ Tile Vertically. one at a time. 4. 5. Click in the SC Flat Prof study to select it. 2.1.Packing Optimization 77 . 7. Ensure only the Body layer is on for both studies. Click View ¨ Lock ¨ and choose all of the locks. 6. • The result should be displayed in both studies. 3. Ensure that only SC Flat Prof and SC Prof 1 studies are the only open studies.Table 14: SC Prof 1 parameters Parameter Value Velocity/pressure switch-over Automatic Pack/holding control Packing pressure vs time Packing profile As written in Table 13 Figure 24: Shape for the SC Prof 1 packing profile Review the packing results Volumetric shrinkage results To review the volumetric shrinkage results 1. Practice . Click Volumetric shrinkage at ejection to display the result. Click Volumetric shrinkage:Path Plot to activate it.2. Volumetric shrinkage interpretation You should see that the over packing on the gate half of the part has been reduced but not enough. The next profile should address the spike in shrinkage right at the gate and the general trend of lower shrinkage on the gate end of the part compared to the end of fill.1 seconds. Click 1 study. Click in the SC Flat Prof study to select it. Click in the SC Flat Prof study to activate it. h This will be a subtle change and should be around 6 seconds. 4. the slope’s right side slows its reduction in shrinkage and the left side (starting at about 25 mm) decays faster. 3.1. 2. On the next time step. Look for the last time step where the curve’s slope is about constant. This is the knee point. 3. 3. Determine the gate freeze time To plot frozen layer fraction 1. The path plot confirms that the shrinkage at the end of fill is similar. 78 Chapter 4 . Record the value in Table 15 rounded to 0. Click the Frozen layer fraction plot to activate it. To plot volumetric shrinkage with a path plot 1. 5. Click in the SC Prof 1 study to activate it. Record the time in Table 15. Click the Gate layer to activate it. Click (Step Backward) to animate the result one frame at a time to determine when the gate freezes for SC Prof 1. • The plot will automatically be created in the SC Prof 1 study because the plots are locked between the studies. 2. (Step Forward) to animate the result one frame at a time for the SC Prof 3. 6. The shrinkage is still quite a bit lower on the gate half of the part as compared to the end of fill except for the spike in shrinkage at the gate. Gate freeze interpretation Due to the decay in the profile. the gate freezes faster than the first analysis with a constant pressure profile. Pressure results interpretation Nodes 2482 and 3002 which represent areas closer to the gate have significantly been influenced by the profile. • This will represent the knee point pressure for the new profile. to make the volumetric shrinkage have a smaller range across the part. Write the new packing profile in Table 16 based on the information calculated in Table 15.Packing Optimization 79 .1. 5. Click the Pressure:XY plot to activate it. 2.1 seconds. To revise the packing profile 1. • This time was found in a previous task and recorded in Table 15. Record the value in Table 15 to 0. The decay needs to be faster. Calculate the profile’s decay to the knee point by subtracting the transition point from the knee point.1. Table 15: Values for calculating the second injection profile Description Value Knee point Gate freeze time Transition point from Table 12 Knee point pressure Time to knee point Decay time to zero Practice .Pressure results To plot pressure:XY 1. 3. 6. 2. 2. Query the curve for node 2805 to find the pressure at the knee point. Record the value in Table 15 to 0. Click in the SC Flat Prof study to activate it. • This will create the result in the SC Prof 1 study. Click the Pressure:XY plot to activate it. 4. Record the pressure in Table 15 to 1 MPa. 4. 3. the pressure traces need to become closer. Click (Examine result). The pressure decay needs to be changed based on the node 2805 and the volumetric shrinkage path plot.1. However. Record in Table 15 the transition point that was calculated in Table 12.1 seconds. 5. Calculate the decay to zero by subtracting the knee point from the gate freeze time. Double-click (Continue analysis).2 Use the same duration and pressure as Table 13. . Click File ¨ Save study as and enter the name SC Prof 2. Run the third packing analysis The second packing analysis is done with the decayed packing profile defined above. 3. It should look like Figure 25. 3. Double-click (Process Settings) and enter the parameters shown in Table 17. To run the first flow analysis 1. Table 17: SC Prof 2 parameters Parameter Value Mold Temperature 50º C Melt Temperature 230º C Mold-open time 5 seconds Injection + packing + Cooling time 21 seconds Filling control Injection time Fill time 1 second Velocity/pressure switch-over Automatic Pack/holding control Packing pressure vs time Packing profile As written in Table 16 80 Chapter 4 . Click the Plot Profile button on the Pack/Holding Control Profile Settings dialog to see the shape of the profile. The time duration is the Decay to the knee calculated in Table 15. 0 The time duration is the decay time to zero as calculated in Table 15. 2. Activate the SC Prof 1 study.1.Table 16: Second decayed packing profile Time Duration Pressure Description [Sec] [MPa] 0. 4. Use the same constant pressure time and pressure as Table 13. 6. Click Volumetric shrinkage:Path Plot to activate it. • The result should be displayed in both studies. 3. 2. Click (Plot ¨ Properties).4. 2. Set the scale to the range that encompasses both parts. 6.Figure 25: Shape for the SC Prof 2 packing profile Review the packing results To review the volumetric shrinkage results 1. Select (Plot ¨ Properties). Click Apply to see the full scale for each part. To plot volumetric shrinkage as a path plot 1. • The plot will automatically be created in the SC Prof 2 study because the plots are locked between the studies. 6. Practice . Click in the SC Prof 1 study to select it. Rotate the parts to see the variation in shrinkage. 6. 3. Click View ¨ Lock ¨ and choose all of the locks on at a time. Ensure only the Body layer is on for both studies.2. 6. 5. Click Volumetric shrinkage at ejection to display the result.Packing Optimization 81 . 7.1. Set the Scaling to All frames.3. Ensure that only SC Prof 1 and SC Prof 2 studies are the only open studies. Click in the SC Prof 1 study to select it. Click Windows ¨ Tile Vertically. 4. h This will be a subtle change and should be around 6 seconds. However.1. • This new profile will maintain the pressure at the knee for one second then decay to zero in one second 6. • This will represent the second knee point pressure for the new profile. • This time was found in a previous task and recorded in Table 18. Click 2 study. Volumetric shrinkage interpretation The volumetric shrinkage with SC Prof 2 is now much more uniform across most of the part. Query the curve for node 4979 to find the pressure at the second knee point. Record the time in Table 18. Pressure results To plot pressure:XY 1. Look for the first time step where the curve’s slope does not change any more except for the first portion close to the gate. Write the new packing profile in Table 19 based on the information calculated in Table 18. • The first 3 steps of the new profile will be the same as the last profile. 4. Record the pressure in Table 18 to 1 MPa. 3. Table 18: Values for calculating the third injection profile Description Second knee point Pressure at second knee point Time to knee point (first knee. Click in the SC Prof 1 study to activate it. Click the Pressure:XY plot to activate it. 5. (Step Forward) to animate the result one frame at a time for the SC Prof 4. The next analysis will keep the pressure high once most of the part has frozen to pack the area around the gate better. The profile goes to zero too quickly. This is the second knee point. Click (Examine result).4. • This will create the result in the SC Prof 2 study. 2.2.1. the shrinkage is now too high near the gate in SC Prof 2. 5. in Table 15) Second knee point minus first knee point 82 Chapter 4 Value . 4. Click the Pressure:XY plot to activate it. Table 19: Third decayed packing profile Time Duration Pressure Description [Sec] [MPa] 0. Double-click (Continue analysis) Table 20: SC Prof 3 parameters Parameter Value Mold Temperature 50º C Melt Temperature 230º C Mold-open time 5 seconds Injection + packing + Cooling time 21 seconds Filling control Injection time Fill time 1 second Velocity/pressure switch-over Automatic Pack/holding control Packing pressure vs time Packing profile As written in Table 19 Practice . Run the fourth packing analysis The third packing analysis is done with the decayed packing profile defined above. Click File ¨ Save study as and enter the name SC Prof 3. 4. 1 Maintain second knee point pressure for one second.2 Use the same duration and pressure as Table 16. Double-click (Process Settings) and enter the parameters shown in Table 20.1. 3. It should look like Figure 26. Difference between the first and second.knee points. Use the same constant pressure time and pressure as Table 16. and pressure at second knee point.Packing Optimization 83 . The time same time to the knee as in Table 16. To run the first flow analysis 1. Click the Plot Profile button on the Pack/Holding Control Profile Settings dialog to see the shape of the profile. 3. Activate the SC Prof 2 study. 2. 1 0 One second to decay to zero pressure. The shape of the profile will change in each situation. Summary Every part and material is different. In this case. the profile needed to account for a long freeze time. the gate is about half the nominal wall and did not freeze until most of the part. making it more difficult to get the shrinkage distribution desired. If the gate were smaller. 84 Chapter 4 . the gate may freeze too early. As a result.Figure 26: Shape for the SC Prof 3 packing profile Review results Use the same techniques as before to review the results of the last analysis and compare it to previous analyses. The size of the gate can make a significant difference. 2.mpi. Open the study SC3 Fill. The initial processing conditions and criterion are shown in Table 21. Investigate the model geometry using the model manipulation tools. Review the results on the initial packing analysis and make modifications to the profile will reduce the volumetric shrinkage.Snap cover with a 3D mesh Design criteria The packing profile for the snap cover must be optimized.Packing Optimization 85 . To review the model 1. 2. • This study will be used to determine the initial packing pressure. The cooling analysis has already been done.1. Practice . On the Directories tab. 3. Click File ¨ Preferences 2. ensure that Active Units are set to Metric.2. Turn on and off the layers. 2. ensure Default to project directory is checked. Click (File ¨ Open Project) and navigate to the folder My AMI 2010 Projects\AMI Standard 1\Packing_optimization and double click the project file packing_optimization. Table 21: Snap cover parameters Parameter Value Model Type 3D Material SunAllomer PM870A (PP) Mold Temperature 35º C Melt Temperature 230º C Injection + Cooling + Packing 12 seconds Injection Time 1.0 second Initial Packing Pressure 80 % fill pressure Initial Packing Time 10 seconds Target Maximum Shrinkage Variation 2% on the body of the part Project setup To open a project 1. On the General tab. Determine a packing profile to minimize the volumetric shrinkage. Run the first packing analysis. (Start Analysis). Review the packing results for: h Volumetric shrinkage. h Pressure. 1 second Velocity/pressure switch-over By %volume filled. Follow the tasks below to optimize the volumetric shrinkage. 3. 7. Determine an initial packing time. with a constant pressure. SunAllomer PM870A. 2. 4. 86 Chapter 4 . 8. Create an initial packing profile based on the results from the first packing analysis. To run a fill analysis 1. Table 22: Snap cover parameters Parameter Value Mold Temperature 35º C Melt Temperature 230º C Filling control Time. 5. Revise the packing profile and re-run the results as necessary to reduce the volumetric shrinkage variation. 2. h Temperature. 99% Pack/holding control %Filling pressure vs time Packing profile 0 100 10 100 Optimizing a packing profile Developing an optimized packing profile for a part requires the following basic steps: 1. Double-click 3. Double-click (Select materials) and pick the material SunAllomer Ltd. Double-click (Process Settings) and enter the parameters shown in Table 8. h Pressure. Review the packing results for: h Volumetric shrinkage. Determine an initial packing pressure. h Temperature. Run the packing analysis with the packing profile. 6. • Figure 21 shows an example of the Analysis Log. Calculate the maximum packing pressure given the molding machine clamp force listed in Table 23. / The packing pressure can be expressed as a percentage. or the result pressure at V/P switch-over result.Determining an initial packing pressure When clamp force is an issue or may be one. A good starting point is a packing pressure that is 80% to 100% of the filling pressure. using above. 2. Choose the packing pressure you would like to use and record it in Table 9. 3. Record the value in Table 23. If however the calculated pressure is well above the pressure required to fill the part. If a pressure is used. 1. • This will be listed in the Analysis Log. 4.8 Total projected area of the shot where: P max = The maximum packing pressure that can be used. 2000 for english units Safety factor to only use 80% of machine capacity If this calculation indicates the maximum pressure to be at or below the fill pressure.1. it can be rounded to the nearest 1 MPa. the packing pressure that can be used for part is not limited by clamp force. To calculate the maximum packing pressure 1. Therefore. The packing pressure in the analysis is 100% of the fill pressure and is a good starting point. the packing pressure can be any value required to get the volumetric shrinkage distribution required.× Unit conversion × 0. The calculation assumes a uniform pressure distribution across the part. Record the value in Table 23 on page 88. or pressure.Packing Optimization 87 .1. it is important to calculate the maximum packing pressure that could be used. The maximum packing pressure can be estimated by the formula below: Machine Clamp force limit P max = -------------------------------------------------------------------------. This is a conservative estimate as there will never be a uniform pressure distribution. Find the maximum injection pressure. • The maximum packing pressure by the calculation is well above the V/P switchover pressure. This will be the reference pressure for the packing. the clamp force may be a significant problem and will limit the packing pressure to the value calculated. Practice .8 = = = = Tonnes(metric) or tons(US / English units) cm^2 or inches^2 100 for metric units. Review the model details section in the Analysis Log from the SC3 Fill study and find the total projected area of the part. Machine clamp force limit Total projected area of the shot Unit conversion 0. 2. 0063 cm^3 = 0. Double-click Table 24.0000 cm^3 = 14. This time should be more than enough to ensure that the gate has frozen with pressure still being applied.9953 cm^3 = 5.0000 Total projected area = 46.0000 (dy) = 0.9953 cm^3 = 5.0016 cm^3 = 8.Model Details: ============= Mesh Type Laminates across radius of beam elements Total number of nodes Number of 3D nodes Number of HS nodes Number of interface nodes Total number of injection location nodes The injection location node numbers are: = 3D Tetrahedra = 12 = 8517 = 8496 = 20 = 1 = 1 8583 Total number of elements Number of part elements Number of tetrahedral elements Number of sprue/runner/gate elements = = = = 44132 44132 44112 20 Total volume Volume of tetrahedral elements Volume of sprue/runner/gate elements Volume filled initially Volume to be filled Part volume to be filled Sprue/runner/gate volume to be filled Parting plane normal = 14.0000 (dz) = 1. 2.0063 cm^3 (dx) = 0.5483 cm^2 -------------------------------------------------------------------- Figure 27: Example fill analysis Analysis Log Table 23: Packing pressure calculation data Parameter Value Molding machine clamp force limit 75 tonnes Part projected area Pressure at V/P switchover Maximum packing pressure (Calculated) Packing pressure (used) % Determine an initial packing time The packing is optimized on a part that already has cooling run on it.0016 cm^3 = 8. To determine the initial packing time 1. Open the model SC3 Flat Prof. Subtract the injection time from the IPC time. 88 Chapter 4 (Process Settings) and find the IPC time and record it in . The initial packing time is based on the Injection+Packing+Cooling (IPC) time defined in the cooling analysis. Table 24: Determine the packing time Parameter Value IPC time Fill time Initial packing time (calculated) Run the first packing analysis The first packing analysis is done with a constant packing pressure for a time long enough for the gate to freeze off. Double-click (Analysis sequence) and set the sequence to Cool + Fill + Pack. 4. Practice . To run the first flow analysis 1. Record the value in Table 24. 2. 5. Double-click Start Analysis. Double-click (Process Settings) and enter the parameters shown in Table 11. 99% Pack/holding control %Filling pressure vs time Packing profile 0 Pack pressure from Table 23 Pack T from Table 24 Pack pressure from Table 23 3 The study has intermediate results defined by specified times. The times were primarily set up too have finer increments around the time the gate is freezing.3. 3. Table 25: Snap cover parameters Parameter Value Mold Temperature 35º C Melt Temperature 230º C Mold-open time 5 seconds Injection + packing + Cooling time 12 seconds Filling control Injection time Fill time 1 second Velocity/pressure switch-over By %volume filled. Determine the fill time for the analysis SC3 Fill and record it in Table 24. Subtract the fill time from the IPC time and round down to the nearest second. study. Activate the SC3 Flat Prof.Packing Optimization 89 . 4. 90 Chapter 4 . Watch how the shrinkage ranges appear and disappear on the part as the range plotted gets higher. h Click the Specified button. As the range continues to get higher. h Click the Apply button to update the model based on the settings so far. As the plotted range gets higher. Click on the Animation tab.1. h Enter a value of 0. h Click the Value Range button. with the highest shrinkage at the end of fill. Table 26: Volumetric shrinkage range Volumetric shrinkage Min Max SC3 Flat Prof Volumetric shrinkage interpretation The lowest shrinkage is in and near the gate and end of fill. h Set Single dataset for the Animate result over.25. (Results ¨ Plot Properties) to set up the results. Ensure that only the Part layer is turned on. 3.Review the packing results Volumetric shrinkage by a single contour To view the Volumetric Shrinkage results 1. Click 3. indicating the gate area has shrinkage values only lower then the range plotted. h Record the range of volumetric shrinkage to the nearest 0. 3. the shrinkage contour covers the entire part. 3. the area at the plotted shrinkage value gets smaller. h Click OK 4. Click • (Step Forward) to animate the result one frame at a time. there is no longer any contour in the gate end of the part. h Click the Current frame only button. shown on the scale on the right side of the screen. in Table 26. Click the Animation tab. h Set the time to the last one in the Animate result at list. As the shrinkage range gets higher.25% on the part. h Set the Min and Max to the values listed in Table 26. Click the Scaling tab. Click the Volumetric shrinkage result.3. h Click the Apply button to update the model based on the settings so far.2. 2. Volumetric shrinkage probe XY plot interpretation Initially. 4. Click (Front view) to rotate the part to 0. not just at one end. has the lowest shrinkage then gradually increases to the end of fill. Volumetric shrinkage as a Probe XY plot A volumetric shrinkage probe XY plot is an excellent way to watch how volumetric shrinkage changes through the thickness and over time. • Click 6. 3 4 5 Figure 28: Path plot locations for volumetric shrinkage 7. the highest shrinkage in the center of the cross section is at the end of fill. Click (Animate results). As the packing time increases. nearly 17%. Click Probe XY plot as the plot type. 8. 2. 0. the volumetric shrinkage decreases significantly. Practice . To create volumetric shrinkage probe XY plot results 1. Click (Plot ¨ Properties) and set the Y-axis scale from 4 to 17 on the XY Plot Properties (2) tab. 5. to stop selecting locations on the part to graph. Click on the 5 locations shown in Figure 28 starting by the gate. Click (Results ¨ New Plot). At the end of the cycle. 0. Click 1 2 to activate and pick the locations. 3. Curve 2 which is not far from the gate. The portion of the cross-section with the higher shrinkage should be throughout the part.The goal of packing optimization is to make the volumetric shrinkage more uniform. the volumetric shrinkage is very high in the center of the cross section. then OK.Packing Optimization 91 . particularly in the center of the part. Select Volumetric shrinkage from the Available results list. determine the constant pressure time and the decay time. To create the first decayed packing profile. There is about a 7 MPa pressure difference between the gate and end of fill when the end of fill is at its peak pressure. Pressure XY interpretation Node 40750 is at the top of the sprue and node 2372 is at the end of fill. This results in the over packing as shown in the volumetric shrinkage results. The decay will then be linear going to zero when the gate freezes. Click (Results ¨ New Plot). The transition point is between the constant pressure time and the decay time. Select Pressure in the Available plot list. Click OK to create the plot. Select XY Plot in the Plot type list. then press Enter: • 40750. 2372. Transition point Constant pressure time Pressure Decay time Pressure at zero Time Figure 29: Packing profile components 92 Chapter 4 . Click (Select) to stop picking entities. as shown in Figure 29. 2. You will create a decayed packing profile to achieve a more uniform volumetric shrinkage. The transition point is defined by a point midway between the time when the pressure is maximum and the time which the pressure reaches zero. 4. The others go from near the gate to the end of fill. 1136. The gate area also has a high pressure for a much longer time. 3. 6. 5. 2681. Enter in the Entity IDs dialog that opens the following nodes. 1614. The traces of the nodes plotted should be nearly on top of one another during packing to have a uniform volumetric shrinkage. and is based on the pressure trace of node at the end of fill (2372).Pressure results To create an XY plot of pressure 1. 1.Packing Optimization 93 . 2. • This average defines the transition point. Record the value in Table 27.3.1 seconds. 2.2. Record the value in Table 12.1. To determine the transition temperature 1. 5.1 seconds. Record the Transition temperature. • This defines the constant pressure time. Practice . To determine the constant pressure time 1. Examine the time for the end of fill node (2372) when: 2.2. Record the value in Table 12. 5. The pressure is at its maximum. Click the Temperature plot. The pressure goes to zero. 2. 4.2. Subtract the V/P switchover time from the transition point. 2. Click on the Rheological Properties tab. Ensure only the Part layer is on. Find average time between these two times.1. Round it to 0.1. Record the values in Table 27 on page 94. 4. Open the Analysis Log and locate the V/P switchover time in the filling phase status table. 3. Click (Examine result). 3. Right-click and select Details. Round the average to 0. 4. _______ºC To plot the Temperature result 1. 3. 2. Determine the Decay time The Temperature result set as a single contour at the transition temperature is used to calculating the decay time by determining the time when the gate is frozen and subtracting the transition point time. 3. • The gate is frozen at the earliest time step with the contour separates.1. 3. Click the Methods tab. 5. in this case 100%. Record the value in Table 27. Click the Contour button. the packing pressure is set by packing pressure directly. 1. Figure 30: Gate just frozen To determine the pack pressure 1. Check the Single Contour box. For all subsequent packing analyses.4. 3. 6. • The first packing analysis set the packing pressure as a percentage of the fill pressure. 3.2.3. 5. 3. Round it to nearest 1 MPa. 4. Click (Results ¨ Plot Properties). 3. Table 27: Values for calculating the first injection profile Description Time when end of fill node reaches maximum pressure 94 Chapter 4 Value . Zoom up on the gate area so you can see the gate and surrounding area of the part. 6.2. Record the value in Table 12. as shown in Figure 30.1. Examine the Analysis Log file to determine what that pressure is. Subtract the transition point from the gate freeze time. in the filling phase status table. Record the value in Table 27.1.1. Click (Step Backward) to animate the result one frame at a time to determine when the gate freezes. Click OK. Open the Analysis Log and locate the Pressure at the end of fill. 1.3. Enter the transition temperature found above in the Contour value field.5. V/P switchover time (Constant pressure time) Gate freeze time Gate freeze time . To run the first flow analysis 1.1.0. 4.Transition point (Decay time) Packing Pressure Create an initial packing profile Reviewing the results from the packing analysis with a constant profile is used to write the first packing profile. Double-click Prof. The time duration is the Constant pressure time . It should look similar to Figure 31. The pressure is the same packing pressure used above. Click File ¨ Save study as and enter the name SC3 Prof 1. 2. The packing profile is described in Table 28. Table 28: First decayed packing profile Time Duration Pressure Description [Sec] [MPa] 0. This is the time required to go from the V/P switchover to the packing pressure.Table 27: Values for calculating the first injection profile Description Value Time when end of fill node at 0 pressure Average between the first two times (Transition point) V/P switchover time Transition point . Activate the SC3 Flat Prof. The pressure is the Packing pressure defined in Table 27. Double-click (Process Settings) and enter the parameters shown in Table 29.2 seconds. Run the second packing analysis The second packing analysis is done with the decayed packing profile defined above.Packing Optimization 95 .2 seconds defined from Table 27. Click the Plot Profile button on the Pack/Holding Control Profile Settings dialog to see the shape of the profile. study. (Injection location) to delete the results copied from SC3 Flat 4. 3. Practice . 0 The time duration is the decay time defined in Table 27. This time is used to allow the machine to react to the pressure change.2 The time duration is 0. 5. Ensure that the SC3 Prof 1 is active. 96 Chapter 4 . Double-click the Start Analysis icon . 2. only the Part layer is turned on and results are not locked. 99% Pack/holding control Packing pressure vs time Packing profile As written in Table 28 Figure 31: Shape for the SC3 Prof 1 packing profile Review the packing results Volumetric shrinkage results To review the volumetric shrinkage results 1. Table 29: SC3 Prof 1 parameters Parameter Value Mold Temperature 35º C Melt Temperature 230º C Mold-open time 5 seconds Injection + packing + Cooling time 10 seconds Filling control Injection time Fill time 1 second Velocity/pressure switch-over By %volume filled. Click on Volumetric shrinkage result. h Click OK 4.3. However.1. 3. 10.25. the volumetric shrinkage is more uniform across the part. Click on SC3 Flat Prof to activate it. h Click the Value Range button. 5. 3. 6. h Set the time to the last one in the Animate result at list. 3. in particular the scale. Click (Results ¨ Plot Properties) to set up the results. h Click the Apply button to update the model based on the settings so far. Click (Results ¨ Plot Properties). All Plots and All Animations.Packing Optimization 97 . Practice . Click Windows ¨ Tile Vertically.25% in Table 30. 8. Click View ¨ Lock ¨ and choose All View. h Record the volumetric shrinkage range to the nearest 0. Watch how the shrinkage ranges appear and disappear on the part as the range plotted gets higher. h Click the OK button to update the model based on the settings so far. h Enter a value of 0. 8.1. Click on the Animation tab. Ensure that only SC3 Flat Prof and SC3 Prof 1 studies are the only open studies. Click • (Step Forward) to animate the result one frame at a time. 7. Click the Scaling tab. 9. Table 30: Volumetric shrinkage range Volumetric shrinkage Min Max SC3 Flat Prof (from Table 26) SC3 Prof1 Volumetric shrinkage interpretation With the SC3 Prof 1 result. h Click the Current frame only button. The there is more of the part has the higher shrinkages. h Set the Min and Max to the values listed in Table 30 on page 97 encompassing both the SC3Flat Prof and SC3 Prof 1 studies. Click on Volumetric shrinkage result. h Click the Specified button. Ensure the plot properties for SC3 Flat Prof study are the same as the SC3 Prof 1 study. h Set Single dataset for the Animate result over.3.2. the shrinkage is not as uniform as it should be. Click the Animation tab. To reduce its shrinkage. Click • (Step Forward) to animate the result one frame at a time. At the end of packing. 3. Click on the SC3 Prof 1 study. Ensure only the Part layer is on. 2. • Since the plots are locked. Click the Probe XY plot to activate it. Chapter 4 . The probe by the gate shows that the shrinkage went up. Gate freeze interpretation Due to the decay in the profile. the packing pressure must be increased. 4. • This will create the result in the SC3 Prof 1 study. Click on the SC3 Flat Prof study. the gate freezes faster then the first analysis with a constant pressure profile. the temperature results of SC3 Prof 1 will be configured like SC3 Flat Prof. 6. 2. the 3 locations in the center of the part have very similar profiles. indicating the packing pressure decayed too quickly. Click on SC3 Flat Prof to activate it. To display volumetric shrinkage as a probe plot 1. 5. The probe at the end of fill has no change compared to the first packing analysis. Determine the gate freeze time To plot the Temperature result 1. • 98 This will create the result in the SC3 Prof 1 study. Zoom up on the gate area so you can see the gate and surrounding area of the part. Pressure results To plot pressure:XY 1. Click the Pressure:XY plot to activate it. Click in the SC3 Flat Prof study to activate it. 2. Click the Temperature plot. Click (Step Backward) to animate the result one frame at a time to determine when the gate freezes. 3. Watch how the volumetric shrinkage changes and is more uniform in the SC3 Prof 1 study. 40750 and the volumetric shrinkage probe plot.Pressure results interpretation Nodes 2681 and 1136 which represent areas closer to the gate have significantly been influenced by the profile. The decay needs to be faster. However.Packing Optimization 99 . Practice . to make the volumetric shrinkage have a smaller range across the part. The location of the profile knee and the decay to zero pressure after the knee will make a difference in the volumetric shrinkage by the gate. The pressure decay needs to be changed based on the nodes 2372. but not go to zero. It will drop then held at a pressure before decaying to zero. the pressure traces need to become closer. Continue revising the packing profile Continue to revise the packing profile to reduce the shrinkage near the gate. 100 Chapter 4 . Packing Optimization 1.Competency check . What can be done to increase the high shrinkage by the gate? Practice . If a part’s volumetric shrinkage is too high. If the part has relatively low volumetric shrinkage near the gate. what can be done to lower the volumetric shrinkage? 2.Packing Optimization 101 . 102 Chapter 4 Evaluation Sheet - Packing Optimization 1. If a part’s volumetric shrinkage is too high, what can be done to lower the volumetric shrinkage? • • Increasing the packing pressure is normally the best way to improve the volumetric shrinkage. Decreasing the injection time may also help in situations where the frozen layer fraction is rather high at the end of fill. A faster injection time will maintain a lower material viscosity and frozen layer fraction. 2. If the part has relatively low volumetric shrinkage near the gate. What can be done to increase the high shrinkage by the gate? • The volumetric shrinkage drops after the packing pressure has dropped to knee and then decays down zero. Use the Volumetric Shrinkage path plot and pressure XY plot as a guide to adjust the packing profile. Small adjustments could make a huge difference. Practice - Packing Optimization 103 104 Chapter 4 CHAPTER 5 Part Insert Overmolding Aim The aim of this chapter is to learn about part insert overmolding capabilities within Autodesk Moldflow Insight. You will also learn how to prepare the models, run an analysis and interpret the results for part insert overmolding projects. Why do it Autodesk Moldflow Insight has various capabilities regarding part insert overmolding analysis depending on the mesh type. This chapter will review the capabilities and describe how to use it. Overview In this chapter you will: • Review the terms related to part insert overmolding and related technologies used in Moldflow. • Review the part insert overmolding capabilities within Autodesk Moldflow Insight. • Learn how to prepare models for part insert overmolding. • Learn how to run an analysis with part inserts. • Learn how to interpret results specific to part inserts. Part Insert Overmolding 105 106 Chapter 5 . The Insert will be checked and corrected.Part insert overmolding This chapter uses tetrahedral model for the practice and is described below. Practice .Part insert overmolding 107 . Table 31: Model used for part insert overmolding Description Model Connector: starts on page 109 This part is an electrical connector and uses a tetrahedral mesh. A Fill + Pack analysis will be run and the results will be reviewed. then both parts will be meshed with tetrahedral elements.Practice . The starting point will be a Dual Domain surface mesh. 108 Chapter 5 . They were created in Synergy using the same mesh settings. • Mesh the fixed insert and connector with tetrahedral elements.Connector For this connector. • Review the results. Double click the Connector DD study to open it. Insert DD and Connector DD are surface (Dual Domain) meshes. The inserts mesh can be modified if necessary so it is a perfect match to the plastic part. Practice . 2. Reviewing the Mesh The two studies provided. If they don’t perfectly match. • Fix the insert mesh.3. The part insert’s mesh must be compared with the connector’s mesh to determine if the elements perfectly match. 2. • By having the box checked. 2. To open a project 1. Ensure the active units are set to metric units. • Run the analysis. Open project The project contains the necessary files for the connector.2. 2. • Assign the part insert properties.Part insert overmolding 109 . Click File ¨ Preferences. To prepare the connector study 1. Click on the Directories tab. Click (File ¨ Open Project).mpi. and navigate to the folder My AMI 2010 Projects\AMI Standard 1\Overmolding and double click the project file Overmolding.1. Ensure the Default to project directory box is checked. Click (File ¨ Save Study As) and enter the name Connector3D. the following tasks will be done: • Check the surface mesh on the insert and compare it to the connector. there may be some problems with converging in the solvers. • Add the two meshes together. the import dialog will open in the project directory. 2. • New Nodes. Click (File ¨ Save Study As) and enter the name Connector w Insert. Click (File ¨ Save Study). 6. The layer names and the color of the triangles were changed so the insert related layers and the connector related layers can be easily identified when the studies are added together. Rotate the model around as necessary to familiarize yourself with the part. • New Nodes. Highlight the Insert Triangle layer and click color Triangular elements to red. 8. 2. Highlight the Default layer. Ensure that only the Connector triangles and Insert triangles layers are on. Turn off all layers except Insert Triangles. Turn off all layers except Connector Triangles. 4. Change the name of the following layers by replacing New with Connector: • New IGES. To prepare the insert study 1. 6. Change the name of the following layers by replacing New with Insert: • New IGES. 5. Click (File ¨ Add) and select the Insert_dd_1. 110 Chapter 5 . and click (Layer display) to change the (Delete layer) to delete the layer. 2. 3. 5. 3. • New Triangles. Rotate the model around as necessary to familiarize yourself with the part. 7. 4.sdy file to add it to the Connector 3D Study. Activate the Connector 3D study. To compare the insert’s mesh to the connector’s mesh 1. • New Triangles. Click (File ¨ Save Study). Click (File ¨ Save Study As) and enter the name Insert DD 1. 4.3. Double click the Insert DD study to open it. 7. Set the Connector triangles layer to Transparent + Element Edges using the display layer • tool. the insert can be fixed by using a copy of the plastic elements to recreate the portion of the part insert that is not correct. Click and drag the left mouse button up to move the cutting plane in the positive Z-direction until the bottom plane of the insert is shown. Click (Edit cutting planes). 6.4. 3 When using Autodesk Moldflow Design Link. Click (Select) to close the Move cutting plane dialog. Turn off and on the Connector Triangles layer to help visualize the mismatch between the insert and connector. this matching problem will not occur. The warnings with the mesh will be fixed before the analysis is run. Activate and move the cutting plane. Click Close.3. Visually inspect the mesh. This will make it easy to see the elements at the part . • This difference in the mesh will create a solver warnings. 9. 7. Click (Edit cutting planes). Rotate the part to approximately -50 -15 -20. The analysis will run. 7. Fix the insert mesh When the elements of the insert do not match with the plastic part. Uncheck the Show active plane box in the Move Cutting Plane dialog.2.insert interface because the elements in this area will be a different color than the elements in the background.3.2. Click the Make active button. Check the Plane XY box. 8. 7. • You should see that the elements of the insert do not match correctly with the elements of the connector. Deactivate the cutting plane.Part insert overmolding 111 . The following steps are done because Autodesk Moldflow Design Link was not used to prepare the mesh. 9.6. but may not be as accurate as possible. 7.5. 9. Check the Plane XY box. Practice . 7.1. • Rotate pan and zoom the model as necessary to see the insert and connector through the cutting plane. 7.5.1. 9. • Insert Nodes. 2. To delete the insert 1. 2. Click (File ¨ Save Study As) and enter the name Connector Temp. Highlight the following layers and click (Delete layer) to delete the following layers. and top sides of the connector. Do NOT move the entities. To create a temporary study of elements 1. • Insert Iges. • Insert Triangles. 0. Make sure you don’t select any of the internal elements that touch the connector. 112 Chapter 5 . 3.2. Ensure the Connector w Insert study is active. Hold the Ctrl key to select all three regions at the same time. Click the Delete key. 2. 0 on the Viewpoint 2. This temporary study will be used to create a corrected insert. (Front view) or manually enter the rotation 0. in the order listed. Click toolbar. left.3. Figure 32: Band selecting the sides of the connector 2. The connector elements that touch the insert will be saved in a temporary study will all other elements being deleted.1. Band select the right. Click (File ¨ Save Study). as shown in Figure 32. Delete the side elements. Click toolbar. (Front view) or manually enter the rotation 0. 5.1. Click (Enclosed items only) on the Selection toolbar. Make sure you don’t select any of the internal elements that touch the connector. Click Apply. ensuring you don’t enclose any elements normal to the screen. Zoom up on the bottom edge of the remaining elements. Practice . as shown in Figure 33. Delete the Connector IGES layer. Delete the bottom edge elements. 4. Now this can be added to the insert. Click (File ¨ Save Study). 5.1. 6. Band select around the bottom edge elements.4. 3. Click the Delete key. Click (Bottom view) or manually enter the rotation -90.5.Part insert overmolding 113 . Hold the Ctrl key to select the two regions at the same time. 0 on the Viewpoint 4. Click Close.2. the elements of the insert that need to be replaced can be and the new insert mesh can be properly connected. 4.3.3.2. Delete the top and bottom elements. 0. 3. 7. 0 on the Viewpoint toolbar. Figure 34: Band selecting the front edge elements 4. Click (Mesh ¨ Mesh Tools ¨ Nodal Tools ¨ Purge Nodes).2. 0. Figure 33: Band selecting the top and bottom of the connector 3.3. and bottom of the connector. 5. 4.1. 4. The surface mesh of the plastic part that touches the insert has now been isolated into a separate study. Click the Delete key. Band select the top. Band select the insert elements outside the connector elements.sdy file. as shown in Figure 35. All the elements outside the connector elements must be selected. Figure 35: Insert with the touching connector elements overlapping To move the good insert elements to a new layer The insert elements that are not overlapping the connector elements will be moved to a new layer to isolate them. The insert elements that are overlapping the connector elements will be deleted. 3. Click toolbar. Click (Enclosed items only) on the Selection toolbar. To select them all the band must go just above the intersection with the connector elements. 114 Chapter 5 . (Front view) or manually enter the rotation 0. 0 on the Viewpoint 2. 0. 2. 1. You should see where the elements overlap and where the insert elements are not touching the added connector elements. Click (File ¨ Add) and select the connector_temp. Open the Insert DD 1 study. To combine the temporary study with the insert study 1. Figure 36 shows the band selection around one of the insert’s fingers for clarity. 4. Click (Mesh ¨ Mesh Tools ¨ Nodal Tools ¨ Purge Nodes). There are eight places this needs to be done. 5. Turn on the Insert Triangles layer and off all other layers. Click the Delete key. Click Close. 6. To repair the holes 1.1. 6. Click (Assign) the selected insert elements to the layer Keep. 5. Click Apply.2. 3.Figure 36: Insert elements not touching the connector elements are selected 4. Turn on the Connector Triangles and Keep layers. Turn on the Insert Nodes and Connector Nodes layers.Part insert overmolding 115 . as shown in Figure 37. 6. Select all of the displayed triangles and assign them to the Insert Triangles layer. 2. To delete unwanted elements 1. Select all the triangles on the Insert Triangles layer. Practice . Click (New layer) called Keep. Use (Create triangles) to make elements to fill in the sides of the fingers. 2. 116 Chapter 5 . Figure 38: Fill hole on the fingers 4. Use (Merge nodes) to remove smaller elements as shown in Figure 39. Figure 39: Merge nodes 5. Click (Mesh Statistics) to ensure all mesh related problems are fixed. Use (Fill hole) to create the elements on the top and bottom faces of the insert.There are 16 places this needs to be done. Fix any problems that are detected by the Mesh Statistics. Click (Mesh ¨ Orient All) to ensure the mesh orientation is correct.Figure 37: Create side elements 3. as shown in Figure 38. There are eight places this needs to be done. 6.1. Be sure to keep the node on the straight line at the edge of the connector. 6. (Dual Domain mesh) in the study tasks list and select Set Mesh 3. Step through the wizard and correct any problems identified with the wizard’s default settings. Click (File ¨ Save Study as). Click (Select by properties) or type CTRL + B. Practice . 8. 3. Select all the triangles and assign them to the Insert Triangles layer. and name the insert Insert 3D. both parts will be meshed with tetrahedral elements. Click (Mesh ¨ Generate Mesh). Click (Assign to layer) all the nodes to the Insert Nodes layer. Click (Mesh ¨ Mesh Repair Wizard). Mesh the insert. 4. Click (Edit ¨ Remove Unused properties). 6.Part insert overmolding 117 . 5.1. Mesh the fixed insert and connector with tetrahedral elements Now that the insert’s mesh will match the connector’s mesh. 2. Right click Type ¨ 3D. 3. Set the Minimum number of elements through thickness to 4. 7.2. 3. 2. Click Mesh Now. 4. 4. Click (Clean Layer) to remove all layers without entities. Click the Tetra Refinement tab. To finish organizing the study 1. To create a tetrahedral mesh for the insert 1. 3.4. 3.3. Click (File ¨ Save Study).1. Click OK to select nodes. Turn off all the nodes layers. 5. Close the study. Select all the Tetrahedral elements and assign them to the Insert Triangles layer. 5.1. Rename the Insert Triangles layer to Insert Tetras. Ensure the Minimum number of elements through thickness is set to 6.4. Click (Mesh ¨ Mesh Repair Wizard). 5.5. To mesh the connector with tetrahedral elements 1. Turn off the Insert Nodes layer. 5.7. 5. 5. 118 Chapter 5 . Click OK to select nodes.2. 5. Click the Tetra Refinement tab. 6.3.2. 5.8. Activate the Connector Temp study. Assign all the nodes to the Insert Nodes layer. 5. 5. Open the Connector 3D study. Click Mesh Now.Click 6. 3. Right click Type ¨ 3D. Step through the wizard and correct any problems identified with the wizard’s default settings.9.6.3. Click h (Clean Layer) to remove all layers without entities. 5.5.10. Mesh the insert (Mesh ¨ Generate Mesh). There should only be 3 layers remaining. (Edit ¨ Remove Unused properties). (Dual Domain mesh) in the study tasks list and select Set Mesh 5. 5. Click 5. Turn on all the layers except the Insert IGES layer. Highlight the Insert tetras layer and click (Layer display) to change the color of tetrahedral elements on the Insert Tetras layer to orange. Cleanup the model. Click (File ¨ Save Study). 4.1. 2. 6. 5. Click (Select by properties) or type CTRL + B.4.1. 7.5.Part insert overmolding 119 .7. Turn on all the layers except the Default Layer and Connector IGES layer. 3. Click (Select) to close the Move cutting plane dialog.2.8. 3.5. The final study will combine the tetrahedral meshes together to make the study used for analysis. Click OK to select nodes.6. 7. Click the Make active button. Click h (Clean Layer) to remove all layers without entities. Click and drag the left mouse button up to move the cutting plane in the positive Z-direction until the bottom plane of the insert is shown. 2. (File ¨ Save Study). 3. Uncheck the Show active plane box.6.4. 7.2. Cleanup the model. 7. Add the two meshes together Now there should be Dual Domain versions of the connector and Insert. 3. Practice . 3. 7. Select all the Tetrahedral elements and assign them to the New Tetras layer. plus tetrahedral mesh versions. Open the Connector 3D. 7. 7. Click (File ¨ Add) and select the study Insert 3D. 7. Assign all the nodes to the Connector Nodes layer.3. 7. Click (Edit ¨ Remove Unused properties). if not already open. To combine the studies 1. Click (Edit cutting planes). Rename the New Tetras layer to Connector Tetras. There should only be 3 layers remaining. Turn off the Connector Nodes layer.1. Click 8.3. Activate and move the cutting plane. 3. • The mesh is checked to ensure it matches. Click (Select by properties) or type CTRL + B.1. Check the Plane XY box.9.4. 7. 3. 6.3. 5. Visually inspect the mesh. 5.1. To set the part insert properties 1. Set the Local heat transfer coefficients to Perfect contact. Click (Edit ¨ Remove Unused properties). Deactivate the cutting plane. Assign the part insert properties The elements that represent the part insert have the same properties as a plastic part.1.7.3. 3. 5. Click (Edit ¨ Change Property Type). 5. Ensure Metal is the material chosen and click the Select button to set the material. The properties must be set for the insert. Check the Plane XY box. Turn on the Connector Tetras layer 9. 7. Click the Select button to pick a mold material. Select Part insert (3D) and click OK. Ensure the Initial temperature is 25ºC. Select all the elements. 5. 5. 5. Click Close. Click (Edit ¨ Properties). Select Moldmax HH as the material and hit the select button.4. Chapter 5 . 5.2. 5. Set the name as BeCu Insert. • You should see that the elements of the insert now match correctly with the elements of the connector. Click (File ¨ Save Study). Turn off all layers except the Insert Tetras layer.2. 5.4. 5.5. Click 120 (File ¨ Save Study). Click OK. 8. 6. 2. • Rotate pan and zoom the model as necessary to see the insert and connector through the cutting plane. 4. Click OK on the Select material dialog. 5. Click (Edit cutting planes). 6. 6 seconds Velocity/pressure switch-over Automatic Pack/holding control %Filling pressure vs time Packing profile 0. 4. 2. Set the injection location on the center node at the end of the runner as shown in Figure 40. LLC. 3. Set the analysis sequence.Run the analysis Analysis parameters for the connector will be set up and the analysis will be run. Table 32: Connector analysis parameters Parameter Value Mold Temperature 60º C Melt Temperature 250º C Filling control Injection time Fill time 0.Part insert overmolding 121 . Select the material as SABIC Innovative Plastics US. Close all open studies except the Connector 3D study. 2.8 Cooling time 6 seconds 80 80 0 Practice .2. Double-click (Process Settings) and enter the parameters shown in Table 32.2 5 0. Valox 364. Figure 40: Injection locations for the connector 5. Double-click (Analysis Sequence) in the Study Tasks pane.3. 2. To run the analysis 1. Click OK. Select the Fill + Pack analysis sequence. 2.1. Double-click the Connector 3D Pre-Run study to open the study with results already run. Click the Temperature result. Click (Results ¨ Plot Properties). Click the Methods tab. 2. Click 122 (Step forward) to the first time step.5 mm Advanced Options ¨ Solver Parameters ¨ Core Shift Uncheck Perform core shift analysis 6. h Ensure the Element surface display is Transparent. 2. To read in results already run 1. h Ensure Shaded is selected.Specified 6 packing phase 3 cooling phase Solver parameters: Gate diameter . • The analysis will take about a half an hour to an hour to run.3. • A study with results is available so you don’t have to wait for results. Rotate the part to approximately -50 -15 -20 4. Review the results The results to be reviewed are going to concentrate on the results that are influenced by the insert. To plot temperature 1. Chapter 5 .1. 2. Double-click (Start analysis). h Ensure the Color is set to Smooth. Consider using the Job Manager to abort the analysis you are running on this part.2. 2. 3.Table 32: Connector analysis parameters Parameter Value Advanced Options ¨ Solver Parameters ¨ Flow Analysis Intermediate results: • • • 7 filling phase • • Gate contact diameter . Click the Optional Setting tab. Click the Mesh Display Tab. The first task will read in results from an analysis that was done for you ahead of time.4. 2. Use these results if you can’t wait for your analysis to finish. 2. Click OK. 5. Click Probe XY plot as the Plot type. / Other methods of displaying temperature results could be handy. You can see the influence of the mold temperature on the part and insert as these temperatures are the mold temperature of ~60ºC. Click (Animate result). Click (Select) to stop picking curves. Click the Temperature as the new result. Notice how the temperature of the insert and mold are also seen in this result. then the XY Plot Properties(2) tab. 3. many cross-sections can be defined at one time to look at the temperature distribution through the thickness of the part as a shaded image at many locations at once. 1. To plot a temperature probe XY plot 1.4. Enter the Y range manually from 25ºC to 300ºC. Click (Results ¨ New Plot). Click on the following locations: • Portion of part already filled.2.5.Part insert overmolding 123 . Click OK 2. • Insert not in the part. in the full wall thickness.1. Click on the three locations shown in Figure 41. With the probe plot. 1. Practice . Click (Results ¨ Examine result). 1. The initial temperature of the insert can also be seen as it is 25ºC. Click the Properties tab.3. and on the insert not in the plastic. on the plastic part above the insert. 1. 1. • Insert in the part. Figure 41: Temperature probe locations 4. Click (Results ¨ Plot Properties).1. Click the Mesh Display Tab. Click (Animate result). 2. h Ensure the Element surface display is Transparent. h Ensure the Element surface display is Transparent. Click OK.4. Click OK. Click the Pressure at V/P switchover result. Click the Fill time result. 4. 124 Chapter 5 . Click the Methods tab.2. Click (Animate result). Click the Optional Setting tab. Here the last place to fill is over the insert. 2. Click the Methods tab. 3. 2. 2. Click (Results ¨ Plot Properties). Click the Mesh Display Tab. 2. h Ensure Shaded is selected. 2.1. Click the Optional Setting tab. To plot Pressure at V/P switchover 1. Notice how the filling is influenced by the insert. 2. Zoom in and pan on the result to see the filling pattern. To plot Fill time 1. 3. 2.3. There is significant hesitation due to the thickness of the insert and it is not even on the top and bottom of the insert. 2.2. the insert significantly influences the filling. h Ensure the Color is set to banded. 2.4.3. h Ensure Shaded is selected. The pressure highlights the same thing as the fill time. h Ensure the Color is set to banded. 5. h Ensure the Element surface display is Transparent. Click the Mesh Display Tab. Practice . h Set the Value range to 0. Click (Animate result).4. Click the Scaling tab.Part insert overmolding 125 . Click OK. h Set the Animate result over to Single data set. h Ensure the Extended color box is checked. 2.3. Click OK. Click the Velocity result. 2. Click the Scaling tab. Click (Results ¨ Plot Properties).1. Click (Results ¨ Plot Properties). Click the Methods tab. h Click Current frame only. h Set the Min to 6. 2. h Set the Min to 0 and Max to 50 cm/s. Notice how the material races around the thick area of the part. 2.1. Click (Animate result). h Ensure the Extended color box is checked. Click the Animation tab.4. h Set the Animate result at the last time in the combo box list. 2. 2. 3. 2.5 and Max to 13%. h Ensure Vector as darts is selected.2. h Ensure the Element surface display is Transparent. Notice how the volumetric shrinkage over and under the insert is only about half of the shrinkage in the main wall of the part. 2.3. Click the Volumetric shrinkage result. Click the Mesh Display Tab. 2. To plot Velocity 1. To plot Volumetric shrinkage 1. 2.2. 3. The initial temperature of insert can be set.Summary When modeling part inserts. the mesh of the insert must match the mesh of the part. How the insert influences the filling of the part can easily be seen. 126 Chapter 5 . Why do it MPI has various capabilities regarding two-shot sequential overmolding analysis depending on the mesh type. You will also learn how to prepare the models. • Learn how to interpret results specific to two-shot sequential overmolding. Two-Shot Sequential Overmolding 127 . Overview In this chapter you will: • Review the terms related to two-shot sequential overmolding and related technologies used in Moldflow. • Review the two-shot sequential overmolding capabilities within MPI. • Learn how to run a two-shot sequential overmolding analysis. This chapter will review the capabilities and describe how to use this capability. • Learn how to prepare models for two-shot sequential overmolding.CHAPTER 6 Two-Shot Sequential Overmolding Aim The aim of this chapter is to learn about two-shot sequential overmolding capabilities within MPI. run an analysis and interpret the results for two-shot sequential overmolding projects. 128 Chapter 6 . Analyze the other as time permits. One is a Dual Domain mesh and the other uses a tetrahedral mesh. Practice . Use this part if your primary mesh type you use is midplane or Dual Domain. Moldflow Logo: starts on page 139 This part is plaque with the Moldflow logo molded into it. then both parts will be meshed with tetrahedral elements. The second shot will be checked and corrected.Two-Shot Sequential Overmolding This chapter uses several models for the practice and are described below. The starting point will be a Dual Domain surface mesh. The box is molded first with Nylon.Two-Shot Sequential Overmolding 129 . Do the practice for the model of the mesh type you use most. A Fill + Pack analysis will be run and the results will be reviewed. This part uses a tetrahedral mesh.Practice . then the window is molded second with polycarbonate. Table 33: Models used for two-shot sequential overmolding Description Model Box with window: starts on page 131 This part uses a Dual Domain mesh. 130 Chapter 6 . 1. Click (File ¨ Open Project). Ensure the active units are set to metric units. If they don’t perfectly match. 2.2.Box with window For this box and window. there may be some problems with converging in the solvers.3. To open a project 1. the following tasks will be done: • Add the two meshes together. 2. Click (File ¨ Save Study As) and enter the name Box1. Click on the Directories tab. and navigate to the folder My AMI 2010 Projects\AMI Standard 1\TwoShot and double click the project file TwoShot. • New Nodes.Two-Shot Sequential Overmolding 131 . 2. Double click the Box DD study to open it. • Run the analysis. Ensure the Default to project directory box is checked. The window was created from elements of the box and the fill hole tool so the elements will match up. • By having the box checked. • Review the results. To prepare the connector study 1. • Assign the second shot properties. the import dialog will open in the project directory. • Set the analysis type. • New Runners Practice .mpi. Open project The project contains the necessary files for the connector. 3. 2. Box DD and Window DD are surface (Dual Domain) meshes. • New Triangles. Reviewing the Mesh The two studies provided. To practice using Moldflow to step through the problem of viewing and fixing meshes that are not matched Refer to the Moldflow logo practice for information on repairing meshes that are not perfectly matched. Click twice on a layer to change the name of the following layers by replacing New with Box: • New IGES Surface. Click File ¨ Preferences. 2. Click (Layer Display) to change the color Triangular elements on the Box Triangle layer to red. Highlight the Box Triangles layer. Click (File ¨ Save Study As) and enter the name Box & Window1. Rotate the model around as necessary to familiarize yourself with the part. Change the name of the following layers by replacing New with Window: • New Triangles. Activate the Box1 study. 5. 2. Turn off all layers except Box Triangles. The layer names and the color of the triangles were changed so the window related layers and the box related layers can be easily identified when the studies are added together. Click (File ¨ Save Study As) and enter the name Window1. Chapter 6 . • New Nodes. Click (File ¨ Save Study). 4. 5. These studies will be combined to make a final study to be used for analysis. Rotate the model around as necessary to familiarize yourself with the part. To prepare the Window study 1. Add the two meshes together Now there should be Dual Domain versions of the box and window. 3. Turn off all layers except Window Triangles. 6. 7. Click (Layer Display) to change the color Triangular elements on the Window Triangle layer to yellow. 6. Double click the Window DD study to open it.4. 6. Click (File ¨ Add) and select the window1. • New Runners. 2. 5. To combine the studies 1.sdy file. 3. 4. Click (File ¨ Save Study). Click 132 (File ¨ Save Study). To set the feed system properties to 2nd shot 1. 3. 3. Assign the second shot properties The elements that represent the second shot.Two-Shot Sequential Overmolding 133 . part and feed system Must have their properties modified to represent the second shot. Select all the properties in the Select Properties dialog. Click OK. Change the runner. 7. Select all the elements. 5. 2. 4. Ensure the Apply to all entities that share this property is checked. 3. Click the Overmolding Component tab.2. 4. 4. 3. Practice . To set the molding process 1. Click OK.3. Select a runner element. the proper element properties can now be set. Select a gate element. • With the molding process set. 6. Click (Edit ¨ Properties). Click (Edit ¨ Properties). Turn off all layers except the Box Triangles layer. Click Analysis ¨ Set Molding Process ¨ Thermoplastics Overmolding. Select 2nd shot as the component.1. Change the gate. Click the Overmolding Component tab. Turn off all layers except the Box Runners layer.1. Select 2nd shot as the component.4.Set the analysis type The molding process and element properties must be set so a two-shot (overmolding) analysis can be run. 2. 2. To set the part properties to 2nd shot 1. 3.1. 3. 5. Double-click the Process Settings icon Table 34.1. Ultramid A3L HP.2. 2. Run the analysis Analysis parameters for the Box & Window will be set up and the analysis will be run.2. Click OK. 3. Ensure the Apply to all entities that share this property is checked. 5. This allows you to easily distinguish the runners from the first shot and the second shot. 3. Click (Edit ¨ Remove Unused properties). Delete the yellow injection location symbol at the end of the runner.5. 2. Click (Overmolding injection location) to set the injection location at the end of the second shot runner. 5. 5. Select the Fill + Pack + Overmolding Fill + Overmolding Pack analysis sequence. Close all open studies except the Box & Window1 study. To run the analysis 1. 134 Chapter 6 and enter the parameters shown in .4. Select 2nd shot as the component. Click OK. 7. Lexan HF1110.2.1. 8.1.3. 4. Click (Edit ¨ Properties). Click (Material A) to select the first shot material to SABIC Innovative Plastics US. Click (Material B) to select the second shot material to BASF. 5. 2. LLC. The color of the runner and gate turned from green to beige because the default color for the entities is defined for the layer. 6. Set the analysis sequence. Double-click the Analysis Sequence icon in the Study Tasks pane. 3. Click (File ¨ Save Study). Click the Overmolding Component tab. Set the materials.3. 2. • A study with results is available so you don’t have to wait for results.13 cm3/sec. 6. Velocity/pressure switch-over Automatic Pack/holding control %Filling pressure vs time Packing profile . flow rates. Double-click (Start Analysis). packing profiles and cooling time. Velocity/pressure switch-over Automatic Pack/holding control %Filling pressure vs time Packing profile .1 3 0. melt temperatures.Page 1 of 2 Mold Temperature 100º C Melt Temperature 300º C Filling control Flow rate Flow rate 3. Practice . including the mold temperature.5 Cooling time 4 seconds Advanced options ¨ Solver parameters (edit) ¨ Intermediate Output tab Filling phase.Page 2 of 2 Mold Temperature 100º C Melt Temperature 300º C Filling control Flow rate Flow rate 20.5 Cooling time 4 seconds 100 100 0 3 The parameters set up were determined by preliminary analysis. The analysis was set up so the cycle time for each component is the same. • The analysis will take about 30 to 45 minutes to run.4 cm3/sec. Profiled result 20 Packing phase.Two-Shot Sequential Overmolding 135 . Profiled result 20 100 100 0 Flow Settings for Overmolding Component Stage .Table 34: Box and Window analysis parameters Parameter Value Flow Settings for First Component Stage .1 3 0. Set the Y range to Manual with a Min value of 100 and Max of 300. Consider using the Job Manager to abort the analysis you are running on this part. 2. 2. Use these results if you can’t wait for your analysis to finish. 3. The analysis has been done for you.6. The temperature (intermediate profiled) result will be the only specific result viewed. Click the XY plot as the plot type. To plot temperature 1. Ensure that only the following layers are on and the rest are off: h Box Triangles. 1. h Window Triangles. 1. Chapter 6 .3. 0. 1. Double-click the Box & Window Pre-Run study to open the study with results already run. • The second is on the thin rim where the box and window overlap. 136 • The first is on the nominal wall below the runner and to the left of the window.3. Select Normalized thickness as the Independent variable. Click the Plot Properties tab. Set up the part for picking triangles. 1.1.1. 1. 2. Pick two triangles on the part referring to Figure 42. Look at other results as you would like to see the influence if you can see an influence of the overmolding. Pan and zoom to the left side of the part near the runner for shot 2. Click the Back view button to rotate the part to 0. To read in results already run 1. Click the XY Plot Properties (2) tab.2. Click OK. Click (Results ¨ New Plot).5. 180.Review the results The overmolded part has all the same results as does the first shot and a typical flow analysis.4. 1.7. 2. Click the Temperature (Overmolding) result in the available results list.2. as shown in Figure 42. 1. h Window Runners. 2. Set up the part for picking two more triangles.). Click (Animate result. 5. Click the Front view button to rotate the part to 0. 4. 7. Start by looping through the cycle several times then one frame at a time. • The second is on the nominal wall of the window. 0. Pick two more triangles on the part referring to Figure 42. Pan and zoom to the right side of the part near the triangles already picked.1.2. 0. Click (Select) when done picking triangles to prevent from picking any more triangles.Figure 42: First two nodes picked on the box 4. • The first is directly over the red marker on the thin rim.Two-Shot Sequential Overmolding 137 . 4. Figure 43: Second two nodes picked on the window 6. Practice . the box/window interface. the molding process must change to Thermoplastics Overmolding. • Frozen layer fraction. • Volumetric shrinkage at ejection.0 value of the red and blue markers represent the same location in the part. 138 Chapter 6 . Determine how the overmolding influences these results. Interesting results may be: • Pressure. • Bulk temperature. The first and second shot materials must be set. • Shear stress at wall. The elements in the second shot must be defined as the second shot in its properties. To view other results for the overmolded part 1. The mold temperature and cycle times must be the same. You can see by the red data point. • Temperature at flow front. that the second shot heats up the mold surface of the first shot. Click on other results from the overmolding. Summary To create run a two-shot analysis. • Pressure at injection location: XY plot. The first shot insolates to some degree the flow front where the first shot and second shot overlap. • Shear rate bulk. • Fill time.The triangles were picked so the -1. The blue data point shows the second shot is also hotter on the side with the first shot than the steel mold on the other side of the cross section. however. a study has been created with a tetrahedral mesh of the two shots with an analysis run so the warning messages can be found in the analysis log. preventing solver errors. 2.2. Click on the Directories tab. • Run the analysis. To save time. 2. Open project The project contains the necessary files for the connector. Back DD and Logo DD are surface (Dual Domain) meshes. the meshes can be visually inspected. They were created in Synergy using the same mesh settings.3. To open a project 1. • By having the box checked. Reviewing the Mesh The two studies provided. • Mesh the fixed second shot and the first shot with tetrahedral elements. • Assign the Overmolded component properties. and navigate to the folder My AMI 2010 Projects\AMI Standard 1\TwoShot and double click the project file TwoShot. the following tasks will be done: • Review the mesh. Click File ¨ Preferences. • Fix the second shot mesh match. there may be some problems with converging in the solvers. the import dialog will open in the project directory. By using visual inspection. • Add the two meshes together.1. For this part. 2.Moldflow logo For the.Two-Shot Sequential Overmolding 139 . To look at the match.mpi. / Autodesk Moldflow Design Link and higher has the capability to mesh assemblies that will ensure the boundary between components is properly meshed. Using the solvers will indicate problems. the solvers will be used to find problem areas. the exact location of problems can be found. Click (File ¨ Open Project). The logo’s mesh must be compared with the Back’s mesh to determine if the elements perfectly match. • Review the results. it can be time consuming. The inserts mesh can be modified if necessary so it is a perfect match to the plastic part. Ensure the Default to project directory box is checked. but not where the problems are. If they don’t perfectly match. Practice . 2. or checks in the solver can be used to find any problems. Ensure the active units are set to metric units. ** WARNING 301200 **3D Part elements are not matching the overmolded elements at the overmolded interfaces. • You should see that the analysis is checking the model. 6. then the Overmolding. the analysis sequence including overmolding and the injection locations are set. • A message will appear indicating the checking is complete. Open the study MF Logo & Back Test Match.3. ** WARNING 301210 **Nodes from the 3D part or overmolded tetrahedron elements are either inside its opposing tetrahedron element or a significant distance from it. To determine if the part has mesh matching problems 1. Click on the Overmolding Fill+pack-Check tab in the log files area. Close the study. • The study contains a tetrahedral mesh of the two parts. the logo and the back. Fixing the Mesh You found that the mesh has matching errors. The overmolding and part elements are not matching up very well at the interface. the overmolding checking is in progress. Double-click Start Analysis. 5. 7. • There will be nothing in this area until the checking of the model has begun and found an error.1.2. Click (Job Manager). Close the Job Manager. Figure 44: Warnings on an overmolded part with mesh matching problems 4. 2. Chances are that by the time the Job Manager was opened. Watch the Priority Jobs Queue. Click (Abort). • Look for warnings like the one shown in Figure 44. 6. first the flow. 140 Chapter 6 . 6. The elements of the Back study that forms the hole for the logo will be added to the study of the Logo and the meshes will then be connected. The analysis will be started and all that we a looking for are warnings. Highlight the Fill + Pack analysis in the priority queue. One way is to do this is to press CTRL + J. 3. The mesh will be fixed following the tasks below by modifying the Dual Domain meshes then re-creating the tetrahedral mesh. Could affect solver convergence. 6. Abort the analysis when checking the model is complete. 0. Click h (Delete).5. 4. 4.Two-Shot Sequential Overmolding 141 . 2. Rotate the part to ensure you only have elements on the top and bottom faces selected. The remaining elements include the outside edges of the part and the elements that form the logo pocket. as shown in Figure 45. Practice . Click the Front View icon to rotate the part to 0. Figure 45: Selecting the top and bottom faces 3. in several steps ensuring you don’t select the logo pocket.2. Double click the MF Back DD study to open it. Delete the top and bottom elements by: 3. Click and band select the elements on the top and bottom faces of the part. Enter a rotation of -90. -90. To isolate elements of the Back study forming the logo pocket 1.2. 4. The only remaining elements are the elements forming the logo pocket.3. 3.1. Hold the CTRL key and band select the elements forming the outside edges. Click (Enclosed Items Only) on the selection tool bar. Delete the edge elements by: 4. 3. 0.3. Click h (Delete) or the Delete key on the keyboard.4.1. Click 3. viewpoint tool bar. in the 3. (File ¨ Save Study As) and enter the name Back DD to logo. Change the name of the following layers to: h Fix Nodes. 5. 2. h Fix Triangles. Double click the MF Logo DD study to open it. Enter a rotation of -90. 4. Clean up the model by: (Mesh ¨ Mesh Tools ¨ Nodal Tools ¨ Purge Nodes). 5.4. Close the study. 5. To delete the elements of the logo that are not needed 1. in the viewpoint tool bar. Click h Click Apply. Deselect the Enclosed Items Only icon on the selection tool bar. 5. Click (Delete layer).3. Click (File ¨ Save Study As) and enter the name MF Logo fixed.5. 5. Click h 142 (Delete).2. Turn off all layers except Fix Triangles.5. Band select the elements in the middle of the part. Figure 46: Selecting the logo elements to delete 6. The remaining elements include the top of the logo and the end of the two pins. h Click Close. Highlight the IGES Surface click the active layer.1. 5. Click (File ¨ Save Study) 7. 6. -90. Do not move entities to (Clean Layers). as shown in Figure 46. 3. Chapter 6 . 7. 7. Turn off all layers except New Triangles. Click (Mesh ¨ Mesh Tools ¨ Edge Tools ¨ Stitch Free Edges). Click File ¨ Preferences. Click h Click Apply. Ensure the MF Logo Fixed study is open.3.1. Ensure Default to project directory is checked on the General tab. 1. 2. Click OK.Two-Shot Sequential Overmolding 143 . Select the back_to_logo. 2. To add the temporary studies together 1. Click (File ¨ Add). h Click Close. Band select the entire part or type CTRL + A. 7. Click (File ¨ Save Study). 5. 2. 3. 1. Click Close. • Notice how the entire parameter of the logo is not connected between the top and sides. but they are not connected. 4.2. 7. 7.sdy file. Clean up the model by: (Mesh ¨ Mesh Tools ¨ Nodal Tools ¨ Purge Nodes). The free edges will be automatically stitched. 2. • All the free edges should now be fixed. Practice . 8. 6. 4. Turn off all node layers. Turn on all node layers. To connect the meshes that were added together The meshes have been added together.1. Click Open. Click Show.1.2. Click (Clean Layers). 5. 3. The free edges diagnostic is used to show the problem. Click (Mesh ¨ Mesh Diagnostics ¨ Free Edges Diagnostic). Click Apply. 5.1. Click Close. Click (File ¨ Save Study As) and name the study MF Logo 3D. To find and fix the mesh orientation problem 1. Click (Mesh ¨ Mesh Diagnostics ¨ Orientation Diagnostic). 3. 4. Ensure the Minimum number of elements through thickness is set to 6. 1. Click Close on the Mesh Statistics dialog. 3. 2. Click Mesh ¨ Show Diagnostic to toggle off the orientation diagnostic. Step through the wizard and correct any problems identified with the wizard’s default settings. Click Show. 2.4. Mesh the logo (Mesh ¨ Generate mesh). Right click Type ¨ 3D.1.2. Click Mesh ¨ Orient All.1. 3. 4.3. Click 3.1. 2. both parts will be meshed with tetrahedral elements. 4. 144 Chapter 6 . Click the Tetra Refinement tab. • The mesh should not be correct with all elements being blue. Click Mesh Now. Click (Mesh ¨ Mesh Repair Wizard). 3. Notice that the only problem now is the mesh orientation. To create a tetrahedral mesh for the logo 1. Mesh shot one and two with tetrahedral elements Now that the logo’s mesh matches the back’s mesh. 2. Click • (Mesh ¨ Mesh Statistics). Click (File ¨ Save Study).2. (Dual Domain mesh) in the study tasks list and select Set Mesh 3. 6.4.5.3. Mesh the back.2. Change the name of that New Nodes layer to Logo Nodes. 5. 5. Assign all the nodes to a New Nodes layer. Click the Tetra Refinement tab. 6. Click (Mesh ¨ Mesh Repair Wizard). Click Mesh Now.4. 6. 4. 8. 5.1. Rename the IGES Surface layer to Logo IGES Surface. Click (Mesh ¨ Generate mesh). Practice . 4. 5.3. Rename the New Tetras layer to Logo Tetras. Click (Edit ¨ Remove Unused properties). 7. 4. 5. Turn on all the layers except the IGES Surface layer. Double click the MF Back DD study to open it. Click (File ¨ Save Study). 6. Step through the wizard and correct any problems identified with the wizard’s default settings. 5. Click (File ¨ Save Study As) and name the study MF Back 3D. (Dual Domain mesh) in the study tasks list and select Set Mesh 4. 3. Change the color of tetrahedral elements on the Logo Tetras layer to Yellow. Click 5. Right click Type ¨ 3D.1. Select all the Tetrahedral elements and assign them to the New Tetras layer. Turn off the Logo Nodes layer.7. 6. There should only be 3 layers remaining. 2.3. Click OK to select nodes. 5.Two-Shot Sequential Overmolding 145 .1. 4. Organize the nodes. Ensure the Minimum number of elements through thickness is set to 6. (Edit ¨ Select by ¨ Properties) or type CTRL + B. Organize the tetras 6.5. To create a tetrahedral mesh for the back 1.2.4. Click h (Clean Layer) to remove all layers without entities. 5.2.1. 2.8. 6.10.6. To combine the studies 1. Rename that New Nodes layer to Back Nodes. (Edit ¨ Remove Unused properties). 6. Cleanup the model.4. 6. 4.1. 6.Click the Clean Layer icon h There should only be 3 layers remaining. 146 Chapter 6 . 6. Turn off the Back Nodes layer. Assign the second shot properties Currently.7.9. Rename the New Tetras layer to Back Tetras. 6. Click (File ¨ Add) and select the study MF Logo 3D. Click (File ¨ Save Study As) and enter the name MFBack&Logo. the molding process is thermoplastics injection molding therefore the overmolding second component properties can’t be set. 6. if not already open. Click OK to select nodes. 5. Select all the Tetrahedral elements and assign them to the New Tetras layer. Open the MF Back 3D study. Click (File ¨ Save Study). 6. Right-click on the Logo Tetras layer and move it up in the list so it is just below the Back Tetras layer.11.3. Assign all the nodes to a New Nodes layer.5. 6. 6.Click 7. The final study will combine the tetrahedral meshes together to make the study used for analysis. Rename the IGES Surface layer to Back IGES Surface. Add the two meshes together Now there should a tetrahedral mesh version for both the back and logo. Turn on all the layers except the Default Layer and IGES Surface layer.6. (File ¨ Save Study). 3.2. Click to remove all layers without entities. Click the Select by icon or type CTRL + B. Both the molding process and properties must be set. 6. To run the analysis 1. To set the molding process 1. 3. 2. 7.Two-Shot Sequential Overmolding 147 .2. Click (Material B) and set the second shot material to Advanced Elastomer Systems. 5. Turn off all layers except the Logo Tetras layer. 2. 3. 4. Click Analysis ¨ Set Molding Process ¨ Thermoplastics Overmolding. Close all open studies except the MFBack&Logo study. 3. 3. 2. Turn on the Back Tetras layer. Double-click (Analysis Sequence) in the Study Tasks pane. 2. Practice . Click (Material A) and set the first shot material to DuPont Engineering Polymers (Moldflow Verified). Click OK. Select all the elements. Santoprene 121-50 M100. Set the materials.1.3. Zytel 101F NC010. 6. Click (File ¨ Save Study).2. Click (Edit ¨ Remove Unused properties). Select Overmolding second component (3D) and click OK. Click (Edit ¨ Change Property Type).1. Run the analysis Analysis parameters for the Back and Logo will be set up and the analysis will be run. 2. Set the analysis sequence. Select the Fill + Pack + Overmolding Fill + Overmolding Pack analysis sequence. To set the Logo’s properties 1. Table 35: Figure 47: Injection location for the back 5. Set the injection locations. Rotate the model to 130. Click (Overmolding injection locations) to set the injection location for the Logo. 4. Table 36: Box and Window analysis parameters Parameter Value Flow Settings for First Component Stage . as shown in Figure 48. on the end of the post that is attached to the underside of the M in Moldflow.3.Page 1 of 2 Mold Temperature 50º C Melt Temperature 295º C Filling control Injection time Injection time 1 Second Velocity/pressure switch-over Automatic Pack/holding control %Filling pressure vs time Packing profile 0 10 Cooling time 20 seconds 148 Chapter 6 80 80 . 4. 45. 30. Double-click Figure 48: Injection location for the logo (Process Settings) and enter the parameters shown in Table 36. 4. Click (Injection Location) to set the injection location for the Back at the location as shown in Figure 47.1.4.2. including the mold temperature.Table 36: Box and Window analysis parameters Parameter Value Advanced options ¨ Solver parameters (edit) ¨ Intermediate Results ¨ Edit intervals button Filling phase. Double-click (Start Analysis). • The ejection temperature for second shot material is _________ Practice . 99% Pack/holding control %Filling pressure vs time Packing profile 1 8 1 Cooling time 20 seconds 120 120 0 3 The parameters set up were determined by preliminary analysis. Highlight the second shot material in the database and find the ejection temperature. • A study with results is available so you don’t have to wait for results.Two-Shot Sequential Overmolding 149 . 2. The analysis was set up so the cycle time for each component is the same. 6.Page 2 of 2 Mold Temperature 50º C Melt Temperature 200º C Filling control Injection time Injection time 1 Second Velocity/pressure switch-over By % volume filled. packing profiles and cooling time. Consider using the Job Manager to abort the analysis you are running on this part. injection times. 10 Cooling phase. The first task will read in results from an analysis that was done for you ahead of time. Use these results if you can’t wait for your analysis to finish. Double-click MF Back & Logo Pre-Run to open the study with results already run. To read in results already run 1. Review the results The results to be reviewed are mainly going to concentrate on the results of the overmolding (second shot) that are influenced by the first shot. 5 Flow Settings for Overmolding Component Stage . melt temperatures. To plot temperature 1. 2. 5 Packing phase. • The analysis will take about an hour to run. Click the Temperature (3D overmolding) result. 9. Click 4. Click Close.3. 3. Rotate the part to approximately -50 -15 -20 6. Click (Edit cutting planes). Click the Make active button. 3.1. 3. 9.3.2. Click on the following locations: • On the cutting plane of the first shot. Possibly a more efficient way to look at the results is to use a probe plot. Click (Results ¨ New Plot). 4. Stop the animation at a time that interests you. This is done next. • On the cutting plane of the second shot. Click the Animation tab.1.2.3. h Ensure All frames is selected. 8. Deactivate the cutting plane. Click the Temperature (overmolding) as the new result. Rotate the part and zoom as necessary you can see the part on the cutting plane.1. 7. Click OK.3. 4. Click (Edit cutting planes). The temperature of much of the first shot is above the ejection temperature of the second shot material.6. • Notice how the results are displayed on both the first and second shots.5. This is significantly slowing down the cycle time.2. 5. To plot a temperature (3D overmolding) probe XY plot 1. h Ensure the To field is set to the maximum value. 9. 9. h Ensure the Animate result over field is TIme. 3. Activate the cutting plane. 3. Click (Animate result). Click Close. 2. Click the Flip button. Uncheck the Plane ZX box. Click the Scaling tab. 4.4. 3. (Results ¨ Plot Properties). Check the Plane ZX box. Click (Results ¨ Examine result). 150 Chapter 6 . • By picking the same location once from the back view and the second from the front view. 5. then pick in the nominal wall as show in Figure 50. then the XY Plot Properties(2) tab. Pick directly over the first location picked. Click the Properties tab. Enter the Y range manually from 70ºC to 310ºC. Figure 50: Second and third probe plot locations. 4. Click Probe XY plot as the Plot type. the data points represent the back and logo at the same location with the highest X value on the XY graph being the same location in space. Figure 49: First temperature probe plot location 9. Click the Back View icon . 6. 12. 8.Two-Shot Sequential Overmolding 151 . Ensure that both the Back Tetras and Logo Tetras layers are on. 10. Click (Animate result). Practice . Click the Front View icon . Click (Select) to stop picking locations to plot.3. 11. Zoom in on the gate and pick on the back of the part under the logo as shown in Figure 49. Click OK 7. 5. Click Results ¨ Plot Properties. To plot Fill time on the back 1. Click OK. Click (Animate result).3. 3. To plot Velocity on the logo 1. h Ensure the Element surface display is Transparent. 2.4.3.2. h Set the To combo box to about 2s. many cross-sections can be defined at one time to look at the temperature distribution through the thickness of the part as a shaded image at many locations at once. h Ensure the Color is set to banded. There is a very small amount of hesitation due to the pocket for the logo. Click the Mesh Display Tab. 2. 3.1.The plot clearly shows how the second shot heats up the first shot and how the first shot delays the cooling of the second shot. Notice how the material races through the part in the shortest path possible. 2. h Ensure the Element surface display is Transparent. With the probe plot. 2. 2. h Ensure Vector as darts is selected. h Ensure Shaded is selected. 152 Chapter 6 . Click the Scaling tab. Zoom in and rotate on the result to see the filling pattern. Click the Fill time result. Click (Animate result). 2. h Set the Min to 0 and Max to 100 cm/s. / Other methods of displaying temperature results could be handy.1. Click the Velocity (overmolding) result. 2. 2.2. Click the Animation tab. but nothing needs to be done with it. h Ensure the Extended color box is checked. 2. The filling of the back does not indicate any problems. 2. Click Results ¨ Plot Properties. Click the Methods tab.4. Click OK. Click the Optional Setting tab. Click the Methods tab. 4. Click the Mesh Display Tab. 2. Click 7. (Results ¨ Plot Properties). h Click Current frame only. Turn on the locks. 7. Click in the right window. h Ensure the Extended color box is checked. Click the Volumetric shrinkage (overmolding) result. Click (View ¨ Lock ¨ All Views). h Ensure the Element surface display is Transparent. 2. Click (Animate result). Click the Animation tab. What consequences are there due to that shrinkage difference?. Click OK. 7. h Set the Animate result at the last time in the combo box list. Practice . 7. h Set the Animate result over to Single data set. 6. 5.2.1. 7. Set the same plot properties for the other result.5. Notice how the volumetric shrinkage for the back is considerably higher than it is for the logo. To plot Volumetric shrinkage 1.3.4.Two-Shot Sequential Overmolding 153 . Click (Vertical Split). 2. Click in the left window. Click the Scaling tab. 2. Summary The temperature of the first shot has a significant influence on the temperature and heat transfer of the second shot. 7.2. h Set the Value range to 1. 3.1. h Set the Min to 3 and Max to 19%. Click the Volumetric shrinkage result. 8. 4. Click the Mesh Display Tab. Click (View ¨ Lock ¨ All Animations). 154 Chapter 6 . by relating physical inputs to physical outputs in a real-time intuitive way. the engineer should deploy a detailed full factorial experiment. • Injection speed. This is typically the beginning of a lengthy trial-and-error process. However. The typical way a new part is set up is to use a mid-range condition and see how the part behaves. The total number or parameters will easily exceed 10. the engineer makes some changes. and interpretation of results for Design of Experiments (DOE) analysis. and can assist the engineer to improve the part quality. where the analysis takes these parameters and shows all possible interrelations between them and the part quality. • Mold temperature. Consider a very simple case. • Cooling time. • Gate freeze time. Design of Experiments (DOE) Analysis 155 . This experiment will separate the most critical parameters for the part quality and rate them in order of their importance. The possible input parameters that affect the setup include: • Injection pressure. • Cycle time. where a new tool needs to be set up. As a next step. the engineer should first apply a screening experiment. setup. Why do it A DOE analysis will provide you with information about the sensitivity of input parameters about a given part design.CHAPTER 7 Design of Experiments (DOE) Analysis Aim The aim of this chapter is to review the theory. The DOE analysis can identify solutions an engineer may not have considered. experimenting with 10 parameters is very impractical. Instead of applying this trial-and-error approach. • Melt temperature. based on their experience and observations of the new results. • Many others. Depending on what results this first run generates. you will review the results and determine what inputs have the most influence on volumetric shrinkage variation. 156 Chapter 7 . For this part. A second part has the DOE analysis done for you. One you will use to practice setting up the analysis.Overview You will use two parts with a DOE analysis. Design of Experiments (DOE) Analysis This chapter has two models used with DOE and are described below.5 mm section in the center. The model has a very small number of elements so the run time will be short. The plate is 100 mm x 300 mm and has a nominal 2.Practice . determine what is the dominant factor that has the greatest effect on volumetric shrinkage variation. Table 37: Models used with a DOE analysis Description Model Plate: starts on page 158 You will use the Plate model to practice setting up and running a DOE. You will work on both models. To save time the DOE analysis has been run on the cap for you.Design of Experiments (DOE) Analysis 157 .5 mm thick with a 1. Cap: starts on page 160 For the Cap model. Practice . Click OK. Select the sequence. Double-click (Analysis Sequence). • By having the box checked. Open the model plate.2.mpi. 2. 3. 3. Click File ¨ Preferences and ensure that System Units are set to Metric. Setup To open a project 1. a DOE analysis will be set up and run. Turn on and off the layers. 158 Chapter 7 . 2. Click File ¨ Preferences.1. Click (File ¨ Open Project) and navigate to the folder My AMI 2010 Projects\AMI Standard 1\DOE. 3. Double click the project file DOE. Running a DOE analysis To set the analysis sequence 1. Select DuPont Engineering Polymers in the Manufactures field. Ensure the Default to project directory box is checked. 2. Ensure the active units are set to metric units. To set the material 1.Plate For the plate study. 4. To review the model 1. the import dialog will open in the project directory. 4. It is very small so it will not take long to run. 2. Select Zytel 101 NC010 as the Trade name. Investigate the model geometry using the model manipulation tools. Design Of Experiments (Fill + Pack).3. 4. 3. Double-click (Select Material). Click on the Directories tab. 4. Practice .Design of Experiments (DOE) Analysis 159 . Click Finish. Click Next. While the analysis is running look at the results of the cap. Delta 75% Packing time Specified. Delta 75% Expand/compress injection profile Do not change Packing profile multiplier Specified. Delta 20 Mold temperature Specified. Ensure the flow process settings are set like the following: Parameter Value Mold surface temperature 70 Melt temperature 295 Filling control. time Pack/holding control profile settings 0 10 Cooling time Automatic 80 80 3. 3 The analysis will take less than an hour to run. Delta 20 Injection time Specified. 6. Delta 75% Thickness multiplier Do not change 5. 2. Double-click (Process Settings) in the study tasks list. Double-click Start Analysis. 4. Set the DOE settings as follows: Parameter Value DOE Experiment type Taguchi then factorial Number of factors 3 Melt temperature Specified. Injection time 1 Velocity/pressure switch-over Automatic Pack/holding control %filling pressure vs. To set up the DOE 1. 2 seconds %Volume filled 99% Pack/holding control %Filling pressure vs. time %Filling pressure vs.Reviewing the results of the cap To review the inputs of the DOE analysis 1. Delta 50% Packing time Specified. Parameter Value Taguchi ranking method Based on whole range Flow front temperature criterion weighting 0 Shear stress criterion weighting 0 Injection pressure criterion weighting 0 Clamp tonnage criterion weighting 0 Volumetric shrinkage criterion weighting 5 Sink index criterion weighting 0 160 Chapter 7 . 5824S (PP) Mold surface temperature 40ºC Melt temperature 230ºC Injection time 1. Ensure the DOE settings for the cap are as follows: Parameter Value DOE Experiment type Taguchi then factorial Number of factors 4 Melt temperature Specified.0 0. Delta 30ºC Mold temperature Specified. Open the cap model. Delta 75% Expand/compress injection profile Do not Change Packing Profile Multiplier Specified. 2.5 seconds 100 85 85 0 3. Ensure the flow analysis settings for the cap are as follows: Parameter Value Material Flint Hills Resources (Formerly Huntsman). Delta 30ºC Injection time Specified.5 Cooling time 2.0 1. Ensure the DOE Advanced options are as follows. time 0. Delta 75% Thickness multiplier Do not change 4.0 6. 1.93008 Packing profile multiplier 3 1. Move the scroll bars for the three remaining factors.07023 Figure 51: Example Taguchi criterion ranking To review the Volumetric shrinkage variation (DOE):XY Plot 1. 6. Set the Y range (scale) to Min 0. • For each quality criterion.98251 Mold wall temperature 4 1. there is a ranking of the factors that influence the criterion. Click on the logs check box to open it. • Record the dominant factor for each quality criterion in Table 38 on page 163. 6. Parameter Value Part weight criterion weighting 1 Cycle time criterion weighting 1 To review the Analysis Log file 1.83700 Injection time 2 2. Open the Properties for the result. 4.38635 Packing time 5 0.Design of Experiments (DOE) Analysis 161 . • When interpreting these weightings. a Fill or Fill + Pack and what factors were changed and by how much. 2.1. 4. Click Plot Properties on the Explore Solutions Space dialog. 4. Practice . • Packing time is checked because this is the highest factor. This can have a significant influence on the weightings. Click on the Volumetric shrinkage variation (DOE):XY Plot. Scroll to the Taguchi criterion ranking results. Determine the factors required so Volumetric shrinkage variation is least sensitive to packing time. it is important to remember what type of DOE was run. Record the settings in Table 40 on page 163. 5. 2. 3. Figure 51 is an example of one of the criterion.8. Flow front temperature criterion weightings: ------------------------------------------------------Factor Rank Weighting (%) Melt temperature 1 87. Check Packing time to make that factor the X-axis.2. Click OK. • This occurs when the slope of the line is lowest.5 and Max 1. on the XY Plot Properties(2) tab. • Record all the factors and ratings for Volumetric shrinkage in Table 39 on page 163. 7.2. Find a set of conditions that has a low magnitude of volumetric shrinkage. To review the remaining XY plots 1. Determine the factors required so Volumetric shrinkage variation has the lowest value. Open the properties dialog for the result. 7. 3. 3. 2. 3. • Both are done visually.2.1. Record the settings in Table 41 on page 163. 2. 3. Are the conditions the same? 162 Chapter 7 . Find a set of conditions that has a low volumetric shrinkage variation. 3. Adjust the scroll bars. Plot the Volumetric shrinkage at ejection (DOE) result.1. To view the contour results 1.7. Use Explore Solution space dialog to find what conditions make the result the least sensitive to change.3. Turn off the Gate and Runner layers to leave only the Part layer on. Find the conditions where any one point on the curve is lowest for any combination of conditions.4. Review the remaining XY plots. conditions least sensitive to packing time Factor Value Melt temperature Mold temperature Packing profile multiplier Table 41: Volumetric shrinkage.Design of Experiments (DOE) Analysis 163 . conditions for lowest variation Factor Value Melt Temperature Mold Temperature Packing time Packing profile multiplier Answers for the tables are on page 164. Practice . highest factor Quality Criteria Factor Weighting Flow front temperature Shear stress Injection pressure Clamp tonnage Volumetric shrinkage Sink Index Part Weight Cycle time Overall quality Table 39: Volumetric shrinkage criterion weightings Factor Weighting Table 40: Volumetric shrinkage.Worksheets Table 38: Taguchi criterion rankings. 2% Table 44: Volumetric shrinkage.9 Sec.Answers Table 42: Taguchi criterion rankings. highest factor Quality Criteria Factor Weighting Flow front temperature Melt temperature ~89% Shear stress Packing profile multiplier ~90% Injection pressure Packing profile multiplier ~61% Clamp tonnage Packing profile multiplier ~89% Volumetric shrinkage Packing time ~83% Sink Index Packing time ~52% Part Weight Packing time ~36% Cycle time Packing time ~93% Overall quality Packing time ~89% Table 43: Volumetric shrinkage criterion weightings Factor Weighting Packing time ~83% Packing profile multiplier ~15% Melt temperature ~1% Mold wall temperature >1% Injection time >0.75% Table 45: Volumetric shrinkage. conditions least sensitive to packing time Factor Value Melt temperature 260ºC Mold temperature 70 Packing profile multiplier ~1.2% to 1. Packing profile multiplier ~1 164 Chapter 7 . conditions for lowest variation Factor Value Melt Temperature 200ºC Mold Temperature 70ºC Packing time 1. Will the DOE analysis show the optimum molding conditions for the part as a single result? Practice .Competency check .DOE 1. What is the advantage of running a Taguchi then factorial DOE experiment type? 4. What does the Factorial DOE experiment type provide you? 3.Design of Experiments (DOE) Analysis 165 . What does the Taguchi DOE experiment type provide you? 2. 166 Chapter 7 . What is the advantage of running a Taguchi then factorial DOE experiment type? • The program will run first a Taguchi analysis to determine the primary factors to be used in the factorial analysis making more efficient the analysis time and results.DOE 1. 4. The DOE tool will enable you to draw conclusions about which factor to control and by how much so that the required quality is achieved. The DOE analysis will not show the optimum molding conditions for a part. 3.Evaluation Sheet . What does the Factorial DOE experiment type provide you? • The Factorial analysis performs a full factorial analysis and gives the user information of the kind and level of interaction between the variables. What does the Taguchi DOE experiment type provide you? • The Taguchi performs a screening analysis which allows the user to determine which variables have the major impact on the part. Will the DOE analysis show the optimum molding conditions for the part as a single result? • You need to look very carefully at the DOE results to be able to draw conclusions from it. Practice . 2.Design of Experiments (DOE) Analysis 167 . 168 Chapter 7 . Overview This chapter applies to all mesh types.CHAPTER 8 Projects Aim This chapter contains parts of many different types with many problems to be solved. • Determine the gate location for a light holder on page 177. • Determine the gate location for the paper holder model to minimize weld lines on page 178. from translation issues to difficult to solve filling problems. • Determine type of tool and gate location for the Grab-it model on page 176. • Optimize a 4-cavity tool for the Snap Cover model on page 182. One or more of these can be worked on. • Finding a gate location for a dustpan on page 175. • Find the gate location and size the runner system for a cover on page 172. it will provide a variety of problems to investigate and solve. The projects include: • Finding a gate location on a boot part on page 167. • Find a gate location and size the manifold for the reel model on page 180. • Find a gate location and process settings for the phone housing model on page 179. • Find gate locations and balance runners for the door panel model on page 184. Projects 169 . • Determine gate location and molding conditions for a change tray on page 170. • Determine gate locations for a chest of drawers on page 174. Why do it With many different types of problems. • Optimize the 8-cavity tool for cap on page 168. 170 Chapter 8 . Translate the Boot IGES model. h No air traps that can’t be vented. Sprue located in the center of the tool. 171 .38º. Layout runner system for a 2 cavity tool. h Maximum shear rate below 25. h Shear stress below material limit. h Make material change recommendation if necessary. 2. h Minimum number of weld lines. h Use tunnel gates. h Minimum included angle 10º. h Remove all other mesh errors.000 1/sec. 8. 9.Finding a gate location on a boot part Determine the gate location and processing conditions for a two-cavity boot tool. Determine the gate location. 5. 7. determine a proposed cavity layout and size the runner system. h Sprue included angle 2. h Balanced filling pattern. h Make the orientation consistent. 6. 3. h Must be a Texin grade. Use the TPU Texin 270. A primary concern is air traps that would prevent the boot from having a tight seal. 1. Once the gate location and processing conditions are found. Size tunnel gate. Size runners to minimize runner volume. h Reduce the aspect ratio to below 6:1. Optimize part filling. h The mold is a two-plate tool with a layout of your recommendation. Determine optimum process settings. 4. h Recommend sprue orifice diameter. h Recommend runner sizes. h Make the orientation consistent.Optimize the 8-cavity tool for cap 1. 7. 4. Use PP. Translate the Cap IGES model. 5. Layout runner system for an 8-cavity tool. 3. h Reduce the aspect ratio to a reasonable number. Chapter 8 . h Use as starting point the preliminary sizes. h Use the sketch on the following page. 6. h Remove all other mesh errors. 2. Optimize part filling. h Size the drops if necessary. Optimize the molding conditions and size the feed system for the 8-cavity cap tool. h Determine the gate orifice size. Determine optimum process settings. Size runners to minimize runner volume. Flint Hille Resources P4-011. 172 h Recommend sprue orifice diameter. 3 All dimensions are in millimeters. 173 . The layout can change in necessary. Determine the gate location. h Use edge gates. LG Chemical. Layout runner system for a 4 cavity tool.0mm. 6. h Uniform temperature distribution.4 mm (1/4”). Use. determine the gate location and processing conditions that will keep the flatness of this part to a minimum. Maximum shear rate below 20.Determine gate location and molding conditions for a change tray 1. 8.5mm and the maximum thickness is under 2. Translate the Change_Tray IGES model. See the layout on the next page. 9. the information given and the use of design principles. Optimize volumetric shrinkage to minimize the variation of the shrinkage. h Make material change recommendation if necessary. h Balanced filling pattern. h Remove all other mesh errors.0 mm (0. 174 Chapter 8 . h Make the orientation consistent.040”). h Width less than 6. Use only a fill + pack analysis. 2. h Recommend sprue orifice diameter. Determine optimum processing conditions. h The mold is a 2-Plate tool with a proposed cavity layout.39º. Size edge gate. h Shear stress below the material limit. 7. 3. h Sprue included angle 2. h Must be a HIPS grade. Optimize part filling. h Size runners to minimize runner volume. HIPS 60HR. 5. h Ensure the minimum thickness is at least 1. 10. 4. h Reduce the aspect ratio to a reasonable number. h Minimum thickness 1.000 1/ sec. 3 All dimensions are in millimeters. 175 . h The 4 posts on the under side of the part are translated in as triangles. 9. h Shear stress below the material limit. 5. Ensure the volumetric shrinkage between the cavities is uniform. Use PA66. h The material is a 30% Glass filled Nylon. Optimize part filling. h Remove all other mesh errors. Size the following: h Sprue orifice. 7.Find the gate location and size the runner system for a cover 1. They need to be modeled as beams. h Make the orientation consistent. h Balanced filling pattern. Zytel DMX 61G30H BK407. Find the gate location. h Sprue length is 90. Fiber alignment will dominate warpage. Make sure the gate shear rate is below 25. Use the tool Modeling ¨ Simplify Model. Locate the gate on this part that will help minimize warpage. h Runners. 176 Chapter 8 . Translate the Cover IGES model. 8.49 mm. h Reduce the aspect ratio to below 6:1. 10. 4. 6. 2. h The proposed tool layout is provided. 3. h Edge gates can be used. Layout the runner system. h Edge gates.000 1/sec. h The cavity layout can change. Determine optimum process settings. 177 .3 All dimensions are in millimeters. 2. Find gate location. h Make the orientation consistent. Determine optimum processing conditions. 4. BASF Polystyrol 456 F. 178 h Balanced filling pattern. h Remove all other mesh errors. h Reduce the aspect ratio to below 10:1. Chapter 8 . h Only a small variation in temperature. h Uniform pressure distribution. 5. Optimize part filling. there can NOT be weld lines down the center axis of the part. Minimize the weld lines on the part. Use HIPS. 3. 6. h No weld lines down the center axis of the part. Translate the Drawer IGES model. Determine if the chest of drawers part can be produced with edge gates.Determine gate locations for a chest of drawers 1. Model the hot sprue per the sketch. Find the gate location and size a hot sprue bushing that will be on the part. Ensure volumetric shrinkage is uniform. 7. 179 .000 1/sec. 4. 2. Optimize part filling. 6. Determine optimum processing conditions.Finding a gate location for a dustpan 1. Find gate location. h Remove all other mesh errors. h Reduce the aspect ratio to below 6:1. Translate the Dustpan IGES model. h Balanced filling pattern. 5. Daelim Industrial Co Ltd HD2002. Use PP. h Make the orientation consistent. The 2plate tool will be a single cavity. Size the gate orifice to keep shear to a minimum. h Shear stress below the material limit. h Uniform pressure distribution. 3 All dimensions are in millimeters. Place the gate on the part to have a balanced filling and packing. 8. h Move the gate as necessary to achieve the balanced pattern. h Keep the shear rate below 40. h Size the bore diameter and gate orifice as necessary. 3. Use LDPE. 180 Chapter 8 . h Balanced filling pattern. or a 2-plate tool with a hot runner. h Remove all other mesh errors. Translate the Grabit IGES model. The options include a 2-plate cold runner tool. h Move the gate as necessary to achieve the balanced filling pattern. h Shear stress below the material limit. Basell Polyolefins Lupolen 2420 K. h Reduce the aspect ratio to below 15. 3. Optimize part filling. Determine the type of tool that will need to be constructed for this part. Decide on the gate location then lay out a proposed 4-cavity layout with the proposed runner system. 4.Determine type of tool and gate location for the Grab-it model 1. 5.000 1/sec. Size the gates to keep the shear rate below 30. Find gate location. 6. Design the feed system for the 4-cavity tool based on the gate location chosen. 2. h Make the orientation consistent. Determine optimum process settings. 8. h Consider both edge gates and gates on the surface of the part. 7. h Uniform pressure distribution. a 3-plate tool. BASF. h No weld lines around the opening for the light. 7. Design the feed system for a 1-cavity tool based on the gate location chosen. Only edge type gates can be used. Find a gate location that will minimize the weld lines around the opening for the light. Translate the Light_holder IGES model. 4. h Shear stress below the material limit. Find gate location. h Reduce the aspect ratio to below 6:1. Use PA6.000 1/sec. h Uniform pressure distribution. Ultramid 8333GHI. Optimize part filling. 3. 181 . h Balanced filling pattern. 6. Design a gate and runner system for a 1cavity prototype tool. h Make the orientation consistent. Determine optimum processing conditions. Size the gates to keep the shear rate below 20. h Remove all other mesh errors.Determine the gate location for a light holder 1. 8. 2. 5. Determine the gate location for the paper holder model to minimize weld lines 1. No weld lines on the large curved sides. h Find gate location. Determine optimum processing conditions. Optimize part filling. Balanced filling pattern. 2. Find a gate location that will minimize the weld lines on the large curved sides of the paper holder. 5. Modify the wall thickness if necessary. h Reduce the aspect ratio to below 6:1.9 mm. 4. h 182 Shear stress below the material limit. h Use SAN. 6.6 mm and >1. 3. h Make the orientation consistent. h Ensure the maximum thickness is <5. Translate the Paper_holder IGES model. The tool will be a single cavity 2plate tool. Tyril 100 C. Chapter 8 . Dow Chemical USA. h Remove all other mesh errors. 183 .6 mm and >0. Determine optimum processing conditions. 3. h Balanced filling pattern. High shear stress and weld lines reduce the adhesion of the labels to the part. 4. Optimize part filling. h Minimize weld lines that meet head on.Find a gate location and process settings for the phone housing model 1. h Make the orientation consistent. 6. Find gate location. h Remove all other mesh errors. Use PC+ABS. and processing conditions that minimize these problems. Translate the Phone IGES model. 2.4 mm. Bayblend KU 2-1468. h Reduce the aspect ratio to below 6:1. 5. h Shear stress below the material limit. The phone will be molded with in-mold labels. h Ensure the maximum thickness is <1. Determine a gate location. Lexan SP7606. Find gate location.0 mm and >1. h Balanced filling pattern. Chapter 8 . 2. Optimize part filling. 184 h The drop length is 88. 6. h Make the orientation consistent. Determine optimum processing conditions. The gate location should produce minimal stress in the hub of the part.9 mm. h Shear stress below the material limit in the hub of the part. h Ensure the maximum thickness is <4. h Remove all other mesh errors. Find a gate location and size the manifold for a 2-cavity reel tool. Translate the Reel IGES model. Layout and size the hot runner system.5 mm. h The sprue length is 25 mm. Use PC.Find a gate location and size the manifold for the reel model 1. 5. 4. h Determine the gate diameter. h Size the drop and manifold diameters. h Reduce the aspect ratio to below 10:1. 3. 7. 3 All dimensions are in millimeters. 185 . h The mold is a 2-plate tool with a fixed cavity layout. Determine the gate location and size the runner system for a 4-cavity snap cover tool. 5. Translate the Snap_Cover IGES model. Size tunnel gate. 2. 3.38º. h Sprue orifice diameter 5. Chapter 8 . Determine optimum processing conditions. h Remove all other mesh errors. (See sketch on following page). Lustran ABS 248. Layout runner system based on cavity layout and gate location. h Use tunnel gates. Determine the gate location. Size runners to minimize runner volume. h Sprue included angle 2. h Make the orientation consistent. 7. 8. h Minimum included angle 10º. h Minimum number of weld lines.Optimize a 4-cavity tool for the Snap Cover model 1.56 mm (7/32 inches). A proposed cavity layout is provided. Use ABS. 9. 186 h Sprue located in center of tool. h Maximum shear rate below 30. Optimize part filling. h Reduce the aspect ratio to under 6:1.000 1/sec. h Balanced filling pattern. 6. 4. h Shear stress below material limit. 187 . 8. 5.Find gate locations and balance runners for the door panel model 1. 4. h Clamp force limit 2500 metric tons. h Remove all other mesh errors. 6. h Reduce the aspect ratio to under 20:1. h Make the orientation consistent. Only edge gates can be used. The center of the tool will be at the clamp force centroid. h The mold is a single cavity 2-Plate tool. Optimize volumetric shrinkage within clamp tonnage limit. limit filling to 2000 tons. h Drop length 350 mm long. h Size hot manifold. h Sprue in centroid of clamp force. Size the hot and cold runners necessary to produce the single cavity tool. 188 Chapter 8 . h Balanced filling pattern. Use ABS. Determine the gate locations for the door panel. Determine the gate location(s). Translate the Door_Panel IGES model. Kralastic SXB-367. 2. Optimize part filling. Layout runner system. h Only edge gates can be used. h Sprue length 25 mm long. h Shear stress below material limit. h A hot runner will be designed to deliver material into a cold runner system feeding the gates. 7. h Based on gate location(s). Determine optimum processing conditions. drop(s) cold runners and gates as necessary. h Minimum number of weld lines. 3. • Determining process settings. • Sizing a cold runner system. The tasks which were performed included: • Finding a gate location. • Optimizing multi-cavity tools.What You’ve Learned This chapter demonstrated many problems which may be investigated using Moldflow Plastics Insight. 189 . • Balancing a runner system. 190 Chapter 8 . ................................22 Transition point .......... 161 XY plots ...............................................................................................5 V Volume change ............................. 92 Process settings Molding window .........................3 Using a personal database ....... 90 E Edit a material property ...16 T Target pressure ................................ 19 Analysis Log ................................ 163 Quality criterion ....... 21 Frozen layer fraction .................74.................. 29 Constant pressure time .. 22 C Clamp force ................ 88 Preferred molding window ............................................ 74......................... 16 Molding conditions .. 75 M Maximum machine injection pressure ................................................ 69..................................................................................................................................... create ............................................... 3 Decay time ............................................................................... 70........ 75........... 160 Contour results ............... 73.23 A Add... 88 Determining initial packing pressure ........................................................................................................................................14............................ 161 S Save Study . 87 DOE Advanced options .37.................................................................... 34 Molding window Process settings ..................... 72...... 92 Determine initial packing time ......Index Numerics P 2D Slice zone plot ...................... 87 Pressure............... 22 Balance runners .............................................................74..................................................................... 92 Create a database .... 94 Profile............. 92 U udb .............................16 Pressure XY plot ..................................................69...... 35 B Balance pressure ...................................70.................. 87 Clamp tonnage ......................................... 86 191 ....................................................... 4 Create ............................... 5 F Feasible molding window ............................................ studies ............................................68................................................................................. 95 Time ...............................................23 Volumetric shrinkage ......................................... determine .......... 162 Quality criteria ........ 3 D Database Copy ..... 16 O Optimizing a packing profile ................. 16 Flow rate .................................16 Process Settings Wizard .......69........................................................ 76...................................... 17 Packing Pressure . 192 .

Autodesk Moldflow Insight 2010 Std2 Practice

Comments

Description