1、Designation: D2370 98 (Reapproved 2010)Standard Test Method forTensile Properties of Organic Coatings1This standard is issued under the fixed designation D2370; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. A number in parentheses indicates the year of last reapproval. Asuperscript 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. Scope1.1 This test method covers the determination of th
3、e elon-gation, tensile strength, and stiffness (modulus of elasticity) oforganic coatings when tested as free films.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlya
4、nd are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitatio
5、ns prior to use. Specific hazardstatements are given in Section 7.2. Referenced Documents2.1 ASTM Standards:2D823 Practices for Producing Films of Uniform Thicknessof Paint, Varnish, and Related Products on Test PanelsD882 Test Method for Tensile Properties of Thin PlasticSheetingD1005 Test Method f
6、or Measurement of Dry-Film Thick-ness of Organic Coatings Using MicrometersD3980 Practice for Interlaboratory Testing of Paint andRelated Materials3D4708 Practice for Preparation of Uniform Free Films ofOrganic Coatings3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 elongation
7、, nthe increase in specimen length fromthe point of initial load application to the point of film rupturein a tension test.3.1.2 gage length, nthe initial length of the test specimenbetween the jaws of the tensile tester.3.1.3 stiffness (modulus of elasticity), nthe load per unitarea required to elo
8、ngate the film 1 % from the first point in thestress-strain curve where the slope becomes constant.3.1.4 stress-strain curve, nthe curve resulting from a plotof tensile load against the distance of jaw separation (elonga-tion of specimen).3.1.5 tensile strength (nominal), nthe load per originalunit
9、area at which a specimen fails or yields in a tension (pull)test.4. Summary of Test Method4.1 Free unsupported films of the materials to be tested areprepared. The tensile properties of the free films are determinedby means of a tensile testing apparatus.5. Significance and Use5.1 Tensile properties
10、 determined by this method are ofvalue in studying the behavior of coatings subjected to envi-ronmental stresses, such as those produced by aging andweathering. (See Refs. (1-10).)45.2 Tensile properties may vary with specimen thickness,method of preparation, gage length, rate of load application,te
11、nsile tester response, and type of grips used. Consequently,where precise comparative results are desired, these factorsmust be carefully controlled.6. Apparatus6.1 Equipment for applying films of uniform thickness asdescribed in Practices D823.6.2 Micrometer Film Thickness Gage as described in Test
12、Method D1005.6.3 Tensile Tester of the constant rate of jaw separationtype, equipped with load cells having capacities of 0.2 to 4.4 lb1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcom
13、mittee D01.23 on Physical Properties of Applied Paint Films.Current edition approved Dec. 1, 2010. Published December 2010. Originallyapproved in 1965. Last previous edition approved in 2002 as D2370 98 (2002)1.DOI: 10.1520/D2370-98R10.2For referenced ASTM standards, visit the ASTM website, www.astm
14、.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.4Boldface numbers in parenthes
15、es refer to the list of references at the end of thisstandard.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.(100 to 2000 g), and equipped with an indicating device suchas an electronic constant speed chart recorder, a digital devic
16、ethat displays numerical values, or a printer that records thenumerical values.6.4 Precision Specimen Cutter having a double blade witha foot to hold the sample in place.56.5 Alternative Substrates on which test material can bedeposited.6.5.1 Dental Tin Foil, preferably 1 mil (25 m) thick.66.5.2 She
17、et of FEP (fluorinated ethylene-propylene),7pref-erably 2 mils (50 m) thick, coated with a dry lubricant.8NOTE 1Other substrates that may be suitable are 10-mil (250-m)thick polyethylene (7), photographic paper (8), polished steel (9), andfluoropolymer coated metal panels.7. Hazards7.1 MercuryMercur
18、y is a toxic metallic liquid. Its vaporsare extremely hazardous. Small amounts of spilled mercurycan vaporize sufficiently at room temperature to exceed thethreshold limit values (TLV) of the vapor. Use with adequateventilation (in a hood) and clean up spills immediately. Weargloves when handling me
19、rcury. Keep containers closed. Drop-lets of mercury can be picked up by using a small glass pipetconnected to a suction flask with a rubber hose.8. Test Specimens8.1 The test specimens shall be free films having a widththat is between12 and 1 in. (13 and 25 mm). No specimen shallvary by more than 62
20、 % in width along its entire length. Thelength shall be at least 2 in. (50 mm) longer than the gagelength selected for the test.8.2 Prepare free films by one of the procedures described inTest Method D4708.9. Calibration9.1 Balance, zero, and calibrate the load weighing andrecording system of the te
21、nsile tester in accordance withmethods specified by the manufacturer.10. Conditioning10.1 Unless otherwise agreed upon between the producerand the user, condition the test specimens for at least 24 h at73.5 6 3.5F (23 6 2C) and 50 % relative humidity and testin the same environment.11. Procedure11.1
22、 Select a mutually agreed upon gage length in the rangeof 1 to 5 in. (25 to 125 mm).11.2 Prepare 10 test specimens for each material to beevaluated. These specimens should not exhibit any nicks orflaws. Measure the thickness of each specimen to 60.1 mil (2.5m) with a micrometer in accordance with Te
23、st MethodsD1005, taking five measurements within the gage length area.11.3 Set the jaw separation of the tensile tester at the gagelength selected. Place the test specimen in the grips of thetesting machine, taking care to align the long axis of thespecimen with an imaginary line joining the points
24、of attach-ment of the grips to the machine. Tighten the grips evenly andfirmly to the degree necessary to minimize slipping of thespecimen during test.NOTE 2Mounting is facilitated by the use of air activated jaws.Line-type jaws will minimize slippage and breakage. The application ofpressure-sensiti
25、ve cloth to the ends of the film can improve jaw grip.11.4 Select a mutually agreed upon rate of elongation (strainrate) that is in the range of 5 to 100 %/min. Set the crossheadspeed of the tensile tester to provide this rate for the gagelength chosen.NOTE 3A rate of elongation should be selected t
26、hat is optimum fortesting the types of materials to be evaluated. For relatively brittle films,elongation rates of 5 to 20 % are suggested. For relatively extensible films,elongation rates of 50 to 100 % are suggested. (Refer to Test MethodsD882 for relation of elongation rate to elongation at break
27、).11.5 Elongate the test specimen until rupture of the filmoccurs and evaluate the stress-strain curve as follows:11.5.1 Determine the specimen elongation by measuring theincrease in jaw separation from the point of original loadapplication to the point of rupture.11.5.2 Measure the tensile pull in
28、pounds (kg) required torupture the film.11.5.3 If stiffness is desired, determine the tensile pull inpounds (kg) to elongate the film 1 % from the first point in thestress-strain curve where the slope becomes constant.11.6 Using the procedures in 11.1-11.5, run ten test speci-mens for each material
29、under test.12. Calculations12.1 For each specimen compute the following:12.1.1 The elongation E, in percent from the followingequation:E 5 100SDLLD(1)where:DL = increase in specimen length to break, andL = initial specimen length (gage length).12.1.2 The tensile strength, TS, in pounds per square in
30、ch,from the equation:TS 5 PR!/TW! (2)5The sole source of supply of the JDC precision cutter known to the committeeat this time is the Thwing-Albert Instrument Co., 10960 Dutton Rd., Philadelphia,PA 19154. If you are aware of alternative suppliers, please provide this informationto ASTM International
31、 Headquarters. Your comments will receive careful consid-eration at a meeting of the responsible technical committee,1which you may attend.6Dental tin foil is suitable for this purpose.7Teflon FEP 2-mil film thickness (Card No. 03111, Item #29499) from E. I. duPont de Nemours organic coatings; stiff
32、ness; tensile proper-ties; tensile strengthREFERENCES(1) Ashton, H. E., “Flexibility and Its Retention in Clear CoatingsExposed to Weathering,” Journal of Coatings Technology, Vol 51,No. 653, June 1979, pp. 4152.(2) Ashton, H. E., “Predicting Durability of Clear Finishes for Wood fromBasic Propertie
33、s,” Journal of Coatings Technology, Vol 52, No. 663,April 1980, pp. 6371.(3) Beardsley, Herbert P., and Kennedy, Richard J., “Performance ofExterior Paints Based on a Vinyl Acetate-Ethylene Emulsion Vehicle,”Journal of Paint Technology, Vol 39, No. 505, February 1967, pp.8898.(4) Evans, Robert M., a
34、nd Fogel, Joseph, “Comparison of Tensile andMorphological Properties With Abrasion Resistance of UrethaneFilms,” Journal of Coatings Technology, Vol 49, No. 634, November1977, pp. 5060.(5) Holsworth, Richard M., Provder, Theodore, and Ranig, Alexander, Jr.,“Physical Characterization of Coatings Upon
35、 Aging,” Journal ofPaint Technology, Vol 46, No. 596, September 1974, pp. 7695.(6) Levine, Eli, Lindlaw, William, and Vona, Joseph A., “Some RecentDevelopments in Water-Based Systems,” Journal of Paint Technol-ogy, Vol 41, No. 537, October 1969, pp. 531536.(7) Pierce, Percy E., and Holsworth, Richar
36、d M., “The MechanicalProperties and Performance of Wood Primers,” Journal of PaintTechnology, Vol 38, No. 501, October 1966, pp. 584590.(8) Shur, E. G., and Rubin, H., “Accelerated Testing of Finishes ForHardboard,” Journal of Paint Technology, Vol 41, No. 537, October1969, pp. 537550.(9) Schurr, Ga
37、rmond G., Hay, T. Kirk, and Van Loo, Maurice, “Possibilityof Predicting Exterior Durability by Stress/Strain Measurements,”Journal of Paint Technology, Vol 38, No. 501, October 1966, pp.591599.(10) Yaseen, M., and Ashton H. E., “Effect of Free Film PreparationMethod on Organic Coatings,” Journal of
38、Coatings Technology,Vol49, No. 629, June 1977, pp. 5058.D2370 98 (2010)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of
39、 any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments ar
40、e invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not rec
41、eived a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies)
42、of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D2370 98 (2010)4
