1、Designation: D6077 16Standard Test Method forTrapezoid Tearing Strength of Leather1This standard is issued under the fixed designation D6077; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in pa
2、rentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the measurement of the tearingload of nonwoven fabrics by the trapezoid method for leather.This test method does not apply
3、to wet blue.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.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 e
4、stablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1610 Practice for Conditioning Leather and Leather Prod-ucts for TestingD2813 Practice for Sampling Leather for Physical andChemical T
5、ests3. Summary of Test Method3.1 An outline of a trapezoid (see Fig. 1) is marked on aspecimen cut for the determination of breaking load, and thenonparallel sides of the specimen are clamped in the jaws of atensile testing machine. A continuously increasing load isapplied to the specimen in such a
6、way that the tear propagatesacross the specimen width. The value of the breaking load ofthe specimen is obtained from the load-elongation (stress-strain) curve recorded autographically.4. Significance and Use4.1 The trapezoid tearing load is a tension test in which thetest strength is determined pri
7、marily by the interlockingstructure of the fibers. It is useful for estimating relative ease oftearing of leather.4.2 The procedure can also be used to determine if there isany appreciable difference in the relative strength of the leatherin the parallel and the perpendicular directions to the backb
8、one.5. Apparatus5.1 Tensile Testing Machine, constant-rate-of-traverse type,equipped with an autographic recorder to register the appliedload.5.2 Clamps, with faces measuring 25 by 75 mm (1 by 3 in.)with the longer dimension perpendicular to the direction ofapplication of the load.5.3 Template, opti
9、onal, having the dimensions shown in Fig.1.5.4 Pawls, bolt on a machine to allow motion in only onedirection.6. Sampling6.1 Unless otherwise specified, sample as directed, paralleland perpendicular to backbone or parallel and perpendicular tothe cut part. Sampling per Practice D2813.7. Test Specimen
10、s7.1 Unless otherwise specified, test ten specimens.7.2 Cut the test specimens parallel and perpendicular tobackbone or parallel and perpendicular to the cut part.8. Conditioning8.1 Condition in accordance with Practice D1610. (Thecustomer may specify.)9. Procedure9.1 Test properly conditioned test
11、specimens in the standardatmosphere for testing.9.2 Set the clamps at the start of the test 25 6 1mm(160.05 in.) apart and operate the machine at 300 6 10 mm (12 60.40 in.)/min. Select the load range of the testing machine suchthat the break occurs between 10 and 90 % of the full-scaleload.9.3 Secur
12、e the test specimen in the machine, clamping alongthe nonparallel sides of the trapezoid with the cut halfwaybetween the clamps. Hold the short edge taut and let the longedge lie in folds.1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of
13、Subcommittee D31.05 on Upholstery.Current edition approved Sept. 1, 2016. Published October 2016. Originallyapproved in 1997. Last previous edition approved in 2010 as D6077 - 10. DOI:10.1520/D6077-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Servi
14、ce at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States19.4 Start the machine with pawls disengaged, a
15、nd record thetearing load on the autographic recorder. The tearing load willnot be a single value, but will appear as a series of maxima andminima.10. Calculation10.1 Visually fit a straight line parallel to the elongation axisthrough the maxima, and use this as the maximum load. Repeatthis for the
16、minima. Take the average of these two values as thetearing load for that specimen.10.2 Separately calculate the average of the tearing load ofthe five parallel direction test specimens and the average of thefive perpendicular direction test specimens.11. Report11.1 Report the following information:1
17、1.1.1 Describe the material or product samples,11.1.2 Describe the method of sampling used,11.1.3 Report thickness, and11.1.4 tearing load.12. Precision and Bias12.1 PrecisionA coefficient of variation of about 5 % canbe anticipated.12.2 BiasThe true value of the trapezoid tearing strengthcan be def
18、ined only in terms of a specific test method. Withinthis limitation, the procedure for testing trapezoid tearingstrength has no known bias.13. Keywords13.1 tear strength; tearing load; template; tension test;trapezoidASTM International takes no position respecting the validity of any patent rights a
19、sserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of 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
20、 by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will re
21、ceive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received 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 In
22、ternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) 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 Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 1 Template for Trapezoid Tearing Load TestD6077 162
