Designation: D2370 – 98 (Reapproved 2010) Standard Test Method for Tensile Properties of Organic Coatings1 This standard is issued under the fixed designation D2370; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense. 1. Scope 3.1.1 elongation, n—the increase in specimen length from 1.1 This test method covers the determination of the elon- the point of initial load application to the point of film rupture gation, tensile strength, and stiffness (modulus of elasticity) of in a tension test. organic coatings when tested as free films. 3.1.2 gage length, n—the initial length of the test specimen 1.2 The values stated in inch-pound units are to be regarded between the jaws of the tensile tester. as standard. The values given in parentheses are mathematical 3.1.3 stiffness (modulus of elasticity), n—the load per unit conversions to SI units that are provided for information only area required to elongate the film 1 % from the first point in the and are not considered standard. stress-strain curve where the slope becomes constant. 1.3 This standard does not purport to address all of the 3.1.4 stress-strain curve, n—the curve resulting from a plot safety concerns, if any, associated with its use. It is the of tensile load against the distance of jaw separation (elonga- responsibility of the user of this standard to establish appro- tion of specimen). priate safety and health practices and determine the applica- 3.1.5 tensile strength (nominal), n—the load per original bility of regulatory limitations prior to use. Specific hazard unit area at which a specimen fails or yields in a tension (pull) statements are given in Section 7. test. 2. Referenced Documents 4. Summary of Test Method 2.1 ASTM Standards:2 4.1 Free unsupported films of the materials to be tested are D823 Practices for Producing Films of Uniform Thickness prepared. The tensile properties of the free films are determined of Paint, Varnish, and Related Products on Test Panels by means of a tensile testing apparatus. D882 Test Method for Tensile Properties of Thin Plastic 5. Significance and Use Sheeting D1005 Test Method for Measurement of Dry-Film Thick- 5.1 Tensile properties determined by this method are of ness of Organic Coatings Using Micrometers value in studying the behavior of coatings subjected to envi- D3980 Practice for Interlaboratory Testing of Paint and ronmental stresses, such as those produced by aging and Related Materials3 weathering. (See Refs. (1-10).)4 D4708 Practice for Preparation of Uniform Free Films of 5.2 Tensile properties may vary with specimen thickness, Organic Coatings method of preparation, gage length, rate of load application, tensile tester response, and type of grips used. Consequently, 3. Terminology where precise comparative results are desired, these factors 3.1 Definitions of Terms Specific to This Standard: must be carefully controlled. 6. Apparatus 1 This test method is under the jurisdiction of ASTM Committee D01 on Paint 6.1 Equipment for applying films of uniform thickness as and Related Coatings, Materials, and Applications and is the direct responsibility of described in Practices D823. Subcommittee D01.23 on Physical Properties of Applied Paint Films. 6.2 Micrometer Film Thickness Gage as described in Test Current edition approved Dec. 1, 2010. Published December 2010. Originally approved in 1965. Last previous edition approved in 2002 as D2370 – 98 (2002)´1. Method D1005. DOI: 10.1520/D2370-98R10. 6.3 Tensile Tester of the constant rate of jaw separation 2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or type, equipped with load cells having capacities of 0.2 to 4.4 lb contact ASTM Customer Service at
[email protected]. For Annual Book of ASTM Standards volume information, refer to the standard’s Document Summary page on the ASTM website. 3 4 Withdrawn. The last approved version of this historical standard is referenced Boldface numbers in parentheses refer to the list of references at the end of this on www.astm.org. standard. Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States. 1 6 Using the procedures in 11. preferably 1 mil (25 µm) thick..2 Measure the tensile pull in pounds (kg) required to rupture the film.1 Mercury—Mercury is a toxic metallic liquid. Procedure as an electronic constant speed chart recorder. a digital device 11. TS. photographic paper (8). coated with a dry lubricant.5 6 3. purpose.5. 6. taking care to align the long axis of the NOTE 1—Other substrates that may be suitable are 10-mil (250-µm) specimen with an imaginary line joining the points of attach- thick polyethylene (7). or a printer that records the of 1 to 5 in. CT 06810. stress-strain curve where the slope becomes constant. zero. and ment of the grips to the machine. threshold limit values (TLV) of the vapor.5.5 6. 11.4 Select a mutually agreed upon rate of elongation (strain ventilation (in a hood) and clean up spills immediately. in percent from the following equation: 5 The sole source of supply of the JDC precision cutter known to the committee at this time is the Thwing-Albert Instrument Co. 11.. The application of can vaporize sufficiently at room temperature to exceed the pressure-sensitive cloth to the ends of the film can improve jaw grip.5°F (23 6 2°C) and 50 % relative humidity and test in the same environment.1 Balance. (25 to 125 mm).5. These specimens should not exhibit any nicks or a foot to hold the sample in place.1 The elongation E. Place the test specimen in the grips of the erably 2 mils (50 µm) thick. See Note 1 for alternatives. taking five measurements within the gage length area. Small amounts of spilled mercury Line-type jaws will minimize slippage and breakage. 9. condition the test specimens for at least 24 h at 12. and Pont de Nemours & Co.4 Precision Specimen Cutter having a double blade with evaluated. Keep containers closed.1 Unless otherwise agreed upon between the producer and the user. Calibration 11. Wilmington. vary by more than 62 % in width along its entire length. Conditioning 11. in pounds per square inch.7 pref- length selected. No specimen shall D882 for relation of elongation rate to elongation at break).2 The tensile strength. Its vapors NOTE 2—Mounting is facilitated by the use of air activated jaws.5. PA 19154. connected to a suction flask with a rubber hose. Inc.1 which you may attend.1. Your comments will receive careful consid- eration at a meeting of the responsible technical committee.5 Alternative Substrates on which test material can be µm) with a micrometer in accordance with Test Methods deposited. and calibrate the load weighing and 11. 2 . Set the crosshead gloves when handling mercury.1 The test specimens shall be free films having a width elongation rates of 50 to 100 % are suggested.1-11.8 testing machine. If you are aware of alternative suppliers. Calculations 73.3 If stiffness is desired. However. Item #29499) from E.. firmly to the degree necessary to minimize slipping of the 7.3 Set the jaw separation of the tensile tester at the gage 6. determine the tensile pull in recording system of the tensile tester in accordance with pounds (kg) to elongate the film 1 % from the first point in the methods specified by the manufacturer. Philadelphia. 10960 Dutton Rd. polished steel (9). 7 Teflon FEP 2-mil film thickness (Card No.5. Your com- ments will receive careful consideration at a meeting of the responsible technical committee. For relatively extensible films. numerical values. For relatively brittle films.2 Prepare free films by one of the procedures described in increase in jaw separation from the point of original load Test Method D4708. please provide this information E 5 100 S D DL L (1) to ASTM International Headquarters. 10. The sole source of supply of a dry lubricant (MS-122 Fluorocarbon Release Agent). 9.5. 8. and equipped with an indicating device such 11. from the equation: Inc. du DL = increase in specimen length to break. are extremely hazardous.2 Prepare 10 test specimens for each material to be 6.1 which you may attend. NOTE 3—A rate of elongation should be selected that is optimum for 8. Measure the thickness of each specimen to 60. 12.1 Determine the specimen elongation by measuring the 8. The 11. (13 and 25 mm). elongation rates of 5 to 20 % are suggested.1 For each specimen compute the following: 12. where: 6 Dental tin foil is suitable for this purpose. TS 5 ~PR!/~TW! (2) please provide this information to ASTM International Headquarters. Wear rate) that is in the range of 5 to 100 %/min. (Refer to Test Methods that is between 1⁄2 and 1 in.1. 8 12. Hazards specimen during test. 7. Danbury. I. Test Specimens testing the types of materials to be evaluated. 55 Backus Ave. DE 19898.. D1005.5 Elongate the test specimen until rupture of the film length shall be at least 2 in.1 Select a mutually agreed upon gage length in the range that displays numerical values.1 Dental Tin Foil. was found suitable for this L = initial specimen length (gage length). run ten test speci- mens for each material under test.2 Sheet of FEP (fluorinated ethylene-propylene). Tighten the grips evenly and fluoropolymer coated metal panels. If you are aware of alternative suppliers.. 03111... known to the committee at this time is the Miller-Stephenson Chemical Co. Use with adequate 11.1 mil (2. D2370 – 98 (2010) (100 to 2000 g). speed of the tensile tester to provide this rate for the gage lets of mercury can be picked up by using a small glass pipet length chosen.5 flaws. 10. (50 mm) longer than the gage occurs and evaluate the stress-strain curve as follows: length selected for the test. application to the point of rupture.6 11. it is no longer available. Drop. H. 663.2. following equation: 13. William. The between a material. ogy. in.3 Specimen size (length. 596. lb (kg).. Properties and Performance of Wood Primers. T. D2370 – 98 (2010) where: 13. June 1979. “The Mechanical Basic Properties. Vol 46.. and 13. 41–52. Keywords 13. 537. a film with limited elasticity. 653. (2) Ashton. 13. Vol 41. Vol 52. 531–536.1 Report the mean values obtained with the test speci- mens for: 15. 537.” Journal of Paint Technology. level: discarding those from the remaining five. in. Herbert P. “Some Recent Exposed to Weathering. Robert M. Kirk. suitable for determining the bias for the procedure in this test method for measuring tensile properties using tensile testers. “Possibility Morphological Properties With Abrasion Resistance of Urethane of Predicting Exterior Durability by Stress/Strain Measurements. etc. G. “Effect of Free Film Preparation “Physical Characterization of Coatings Upon Aging.5 Aging and treatment given the specimens. E. tensile testers operated at two elongation rates (10 and 100 %) 12. and 13.5 to 3. mean. pp. H. Choose one of the following procedures for laboratory coefficients of variation were found to be 30 % for discarding spurious values and calculate the mean of the percent elongation and 18 % for tensile strength.” Journal of Method on Organic Coatings. 629. Use the test for 14. obtained by operators in different laboratories should be breaks within the jaw. 12. Joseph A. September 1974. W = width of test specimen. and Ranig.. the following criteria should be used for 12.. where: 14. 501. No.. in. pp.” Journal of Paint Technol- No.1 Reproducibility—Two results for percent elongation basis that the expected errors (nicks or flaws in the specimen.” Films. in. November Journal of Paint Technology.1. Lindlaw. Garmond G. 88–98. PR = tensile pull to rupture. Vol 39. Joseph.5 mils (65 to 90 µm). Richard M. from the 13. 76–95. 63–71. 15. 49.2 Examine the uniformity of the tensile strength and with a specimen gage length of 2 in. (5) Holsworth. and thickness). “Performance of (8) Shur. film. 1977. E. October 1969.” Journal of Paint April 1980. “Comparison of Tensile and (9) Schurr.2 Report the conditions of the test. 13.” Journal of Coatings Technology. width. Vol 49. lower than those for most of the specimens. (mm). pp.1. Vol 38. Two results for tensile strength obtained by operators in 12..” Journal of Coatings Technology.1 Tensile strength. Eli. Percy E. No.3 The stiffness (modulus of elasticity).2 Bias—Since there is no accepted reference material outliers given in Practice D3980 – 88.. No. E.2. 501. pp. No. if desired. and tested by five laboratories. and a very elastic film) were T = thickness of test specimen. Report bias has not been determined. (3) Beardsley.1 elongation. Developments in Water-Based Systems. (mm). Based on remaining results: these coefficients. pp.4 Temperature and relative humidity during test and S 5 ~PE!/~TW! (3) treatment. “Predicting Durability of Clear Finishes for Wood from (7) Pierce.2 Discard the values for those specimens where both different laboratories should be suspect if they differ by more the tensile strength and elongation values are significantly than 70 % of their mean. 584–590. Richard J.2 Elongation. Alexander. This is done on the 14. Precision and Bias PE = pull in pounds (kg) to elongate the film 1 % from the 14. No.1 Use the results from those five specimens showing judging the acceptability of results at the 95 % confidence the highest tensile strength in evaluating all three properties. stiffness. 50–60. Vol 41. tensile strength REFERENCES (1) Ashton. E. and Ashton H. and Kennedy. pp. Technology. 13. tensile proper- 13. “Accelerated Testing of Finishes For Exterior Paints Based on a Vinyl Acetate-Ethylene Emulsion Vehicle. H.1. 1969.) would all tend considered suspect if they differ by more than 118 % of their to produce results on the low side. 505. and Vona. No. No. No... pp.. 634. (50 mm) and specimen elongation results obtained for the ten specimens measured for thicknesses of 2.2. Hay.2. 3 . 13.. (mm).2.. and Holsworth.. and Van Loo.” Hardboard.. (mm).. and Rubin. Theodore.1. Jr. and Fogel.1. Vol Paint Technology. 537–550. No. October Journal of Paint Technology. October 1966. M. (10) Yaseen.2.2. Maurice.” Journal of Coatings Technology. and ties.1 Procedure for preparation of free films. Vol 51. 50–58. slippage in the jaw. The test was conducted with Instron W = width of test specimen.2 Rate of elongation in percent per minute. February 1967. (4) Evans. Richard M. pp. pp. 591–599. Vol 38. S.” Journal of Coatings Technology.3 Stiffness (modulus of elasticity). T = thickness of test specimen. October 1966. Provder.1 Precision—An interlaboratory test of this test method first point in the stress-strain curve where the slope was conducted in which three coatings (representing a brittle remains constant. organic coatings. pp. June 1977. “Flexibility and Its Retention in Clear Coatings (6) Levine. Permission rights to photocopy the standard may also be secured from the ASTM website (www. which you may attend. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585 (phone). 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