Technical informationCellasto ® A cellular polyurethane elastomer Cellasto automobile auxiliary springs Cellasto crane buffers Cellasto seals, damping components and buffers Cellasto bearings to isolate noise and vibration The graphs show experimental data that have been generated with standardized test specimen.65 0. However. Cellasto: 350 kg/m3) 20 40 Cellasto 350 kg/m3 60 80 100 Compression [%] Scale representation of the compression (compressive deformation of Cellasto and rubber between two plates) Low transverse expansion and high volume compressibility .40 0. Cellasto spring elements are therefore suitable for applications where the sourrounding structural space is confined. When applying this data for product development it should be noted that the material properties further depend on installation conditions.60 0. It therefore gains rigidity with increasing compression.The characteristics Quasistatic progressive pressurecompression behaviour Cellasto components are based on a cellular polyurethane elastomer. However.18 g/cm3. Large spring excursion and low block dimension characterize moulded components made of this material. They are characterized by low transverse expansion. The pore volume accounts for 50 – 63 % of the moulded volume. The material is characterized by progressive pressurecompression behaviour. 1. Depending on the amount of the material used the moulded components have densities of 350 to 650 kg/m 3 .50 0. The pore diameters lie in the tenth of a millimetre range and are mainly closed. The realizable spring excursion increases with decreasing density and can reach up to 80 % of the original length of the component. Cellasto components also act as springs in enclosed structural space. first the pore volume and then the material itself is compressed. 4 bulk density g/cm3 0. this is not the case with cellular polyurethane elastomers.35 normal climatic conditions 3 2 Compressive stress[N/mm2] 1 0 0 10 20 30 40 50 60 70 80 Compression [%] Quasistatic progressive pressure-compression behaviour P P 0% 100% rubber 63% Cellasto rubber Compression between two plates Cellasto Compression in enclosed space 120 100 Increase in diameter [%] rubber in a cylinder Compressive stress 80 60 40 20 (45 Shore A) rubber Low transverse expansion and high volume compressibility Compact elastomers show large transverse expansion when compressed. the material is not destroyed by single impacts generating stresses of up to 20 N/mm 2 . dimensional factors and others. The moulded components are produced in a closed-mould foaming process. The maximum compression of Cellasto moulded components depends on their density. 2 Cellasto – a cellular polyurethane elastomer Cellasto in a cylinder 20 60 100 Compression [%] Material grades: Cellasto and rubber in the initial compression range (rubber 45 Shore A.45 0. During compression loading. For Cellasto components a compressive strain of 4 N/mm 2 represents the dynamic continuous load limit.55 0. so that moulded Cellasto components can be used in ambient temperatures of up to 80°C without losses in elasticity behaviour. They are subject to temperature limits.0 Fr eq ue y nc Krit. They are then suitable for applications down to about -40°C. The characteristic curve for Cellasto only changes slightly up to a temperature of approx. For moulded components subject to stresses of constant frequency and constant spring deflection an equilibrium temperature. The resultant family of curves – the figure on the right is an example – enables. [H z] MH 24–50 60 50 180 160 140 120 100 80 Temperature [°C] 60 40 20 0 10 20 1.50 g/cm3 3 2 Compressive stress [N/mm2] -30 °C -20 °C 1 0–80 °C 0 0 10 20 30 40 50 60 70 80 Compression [%] Characteristic curves as a function of temperature Temperature increase caused by damping The material damps a portion of the mechanical energy input and converts it to heat. already in the moulded component development phase. 80°C. Moulded Cellasto components gradually harden with decreasing temperature.63 2.0 0.0 3. 110 ˚C Temperature increase caused by damping Cellasto – a cellular polyurethane elastomer Sp rin g 40 de fle ct io n [% ] 60 3 . They are suitable for applications down to about -30°C. The dissipating heat thereby increases the temperature in the stressed moulded component. 4 bulk density 0. Cellasto components which have hardened at low temperatures regain their elastic properties in the course of mechanical stresses and associated warming up. Moulded Cellasto components that also have to maintain their elasticity at low temperatures can be manufactured from special cryo-flexible Cellasto types. is reached. which has been determined on the basis of standardized form components. Moulded Cellasto components gradually soften with increasing temperature. a prediction as to whether the critical thermal damage temperature would be reached in the foreseen application.The characteristics Characteristic curves as a function of temperature The mechanical properties of plastics are temperature dependent. This temperature should not exceed 110°C. the frequency and number of load alternations crucially determine deformation.5 kg/m 3 N/mm 2 % N/mm % % Cellasto – a cellular polyurethane elastomer 4 .5 5.5 5.0 3.0 450 4. The low increase in deformation accords with the remaining compression set.0 550 5. is extremely slight and can generally be neglected in standard applications. The measurements performed on test specimens – the diagram is but one example of many – are carried out over a period of years. the material becomes softer.0 350 8.5 5.0 3.5 5.0 3. in addition to the initial load and load amplitude.5 5. The diagrams above indicate the reason for this.0 Dimension -60 600 6.5 400 14. extrapolation beyond the time of the measurements is possible due to the linearity of the creep curves. The curve in the diagram showing deformation as a function of load alternations flattens out in the forcecontrolled test.0 500 4. The scale of creep. Hence the specimen approximately returns to its original height at the end of the test.5 5.5 -65 650 7.5 400 18. in comparison with reversible compression. Increasing frequency raises the temperature of the Cellasto specimen.5 400 16.0 3.5 350 10.The characteristics Static load-related creep When dimensioning moulded Cellasto components the increased compression over time at constant load – creep – must be considered from the outset.0 400 3. For otherwise identical loads.0 400 12.0 3. Moreover.0 3. Compression [%] Static load-related creep 80 7 70 60 50 40 30 20 MH 24-65 20 f = 15 Hz f =3 1/3 Hz 20 10 0 102 2 5 10 3 f = 15 Hz f =3 1/3 Hz 2 5 10 4 2 5 10 5 2 5 106 2 Alternating load Dynamic load-related creep Material characteristics Property Bulk density Tensile strength Breaking strength Tear growth resistance Residual compressive deformation at 50%/70h/20°C deformation at 50%/22h/70°C Tested in Material designation: Cellasto MH24 accordance with -35 -40 -45 -50 -55 DIN 53 240 DIN 53 571 Specimen A DIN 53 571 Specimen A DIN 53 515 DIN 53 572 DIN 53 572 350 3.0 400 20. compression increases with increasing load frequency.0 3.5 5. Compression [%] 80 20 70 60 50 40 30 20 10 0 100 2 5 101 2 5 102 2 5 103 2 5 104 2 20 MH 24-60 20 Time [h] Dynamic load-related creep Under dynamic loading. 1. This is the opposite to large movements where the requirement is rapid damping for dynamic and safe driving purposes. with the increasing amplitudes for all material densities.05 1. Vibration and Harshness (NVH) a small damping at low amplitudes of high frequencies is necessary for a good isolation. The diagram shows the dynamic stiffening values at high frequencies in comparison to 1 Hz.0 1 20 40 60 80 100 120 140 160 30 mm MH 24-35 MH 24-45 MH 24-55 MH 24-65 180 200 Frequency [Hz] Very low dynamic stiffening 5 Cellasto – a cellular polyurethane elastomer .1 1.The characteristics Loss angle [°] Amplitude selective damping For many applications in the field Noise.1 mm deflection.1 mm 1. The diagram clearly shows the steep rise in “loss angle” (a measurement of damping).25 1.3 1. These qualities show Cellasto as the ideal material for use against vibration and to improve noise isolation when used in the construction of many load carrying bearings. The stiffening will reduce with the increase of material density.15 1. These values are measured at a precompression of 30 % and an amplitude of 0.2 ø 30 mm 1.35 Amplitude: 0.4 Precompression: 30% 1. These seemingly contrasting requirements are met equally well with the use of Cellasto. 10 Precompression: 30% Frequency: 10 Hz MH 24-35 MH 24-45 8 6 MH 24-55 MH 24-65 4 ø 30 mm 30 mm 2 0 0 1 2 3 4 5 Amplitude [mm] Amplitude selective damping Dynamic stiffening [in comparison to 1 Hz] Dynamic stiffening Cellasto demonstrates a very low stiffening up to high frequencies. The information merely ser ves as general information and does in no way constitute a guarantee of any specific product conditions or properties (product specification). In product development the company has access to the whole research and development potential of the parent company. This starts with processing the reactive base materials.BASF Polyurethanes GmbH The semifinished products and components division processes cellular polyurethane elastomers to Cellasto semifinished products and moulded components. up-to-date vibration simulation.com www. Sophisticated process assurance guarantees a high quality standard. CAD technology. Please contact our headquarters or our sales outlet with regard to the availability of products. Because of the multitude of influences in the processing and application or our products they do not release the buyers of our products from implementing their own tests and trials. tried and tested inspection methods and practice-oriented component testing facilities. through the foaming process. Box 1140 49440 Lemfoerde Germany Phone +49/54 43/12-23 02 Fax +49/54 43/12-21 05 E-mail cellasto-eu@basf. (10/10) KU/WM. Information regarding quality and useful life or other features do not represent guarantees. Moreover. The details do not describe the suitability of the product for specific applications and purposes. The semifinished products and components division develops the moulded components to customer specifications. to the moulded Cellasto components. the company has the backup of wide-ranging experience. Any existing commercial rights and existing laws and regulations must be obser ved under the responsibility of the recipient of our products.pu.O. ® registered trademark of BASF Polyurethanes GmbH BASF Polyurethanes GmbH European Business Management Microcellular Elastomers (Cellasto ® ) P.basf. 180-10-10/GB .eu The information provided here is consistent with the current state of our technical knowledge and experience and replaces the information contained in previous versions.