1、Designation: D4704 00 (Reapproved 2010) D4704 12Standard Test Method forTearing Strength, Tongue Tear of Leather1This standard is issued under the fixed designation D4704; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 last revision. 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 is intended for det
3、ermining the tearing strength of leather by measuring the force required to tear aspecimen cut perpendicular to the surface. This test method does not apply to wet blue.1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconversio
4、ns to SI units that are provided for information only and are not considered standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices a
5、nd determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1610 Practice for Conditioning Leather and Leather Products for TestingD1813 Test Method for Measuring Thickness of Leather Test SpecimensD2209 Test Method for Tensile Strength of Leather
6、D2813 Practice for Sampling Leather for Physical and Chemical Tests3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 tongue tear strengththe load required to tear the leather between two tongues formed by splitting the leatherperpendicular to its surface.4. Significance and Use4
7、.1 Knowledge of the strength of the sample can be a determining factor for the end use of the product.5. Apparatus5.1 Testing Machine, as described in Test Method D2209.5.2 Thickness Gage, a dead weight type of thickness gage as described in Test Method D1813.5.3 Steel Die, to cut test specimens.6.
8、Sampling and Test Specimens6.1 Unless otherwise specified, sample the leather according to Practice D2813.6.2 The specimen shall be a rectangular piece of leather, 1 4 in. (25.4 101.6 mm) by the full thickness of the unit. It shallhave a 316 in. (4.76 mm) hole located on the long axis 1 in. (25.4 mm
9、) from one end and shall be split along its axis from the holeto the other end to form two tongues. The direction of the long axis of the specimen relative to the backbone shall be noted. SeeFig. 1.1 This test method is under the jurisdiction of ASTM Committee D31 on Leather and is the direct respon
10、sibility of Subcommittee D31.07Physical PropertiesCurrent edition approved Oct. 1, 2010Sept. 1, 2012. Published November 2010 October 2012. Originally approved in 1987. Last previous edition approved in 20052010as D4704 00 (2005).(2010). DOI: 10.1520/D4704-00R10.10.1520/D4704-12.2 For referenced AST
11、M standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user
12、 of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as
13、published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States17. Conditioning7.1 All specimens shall be conditioned for 48 h in an atmosphere maintained at 73.4 6 3.6F (23 6 2C) and 50 6 4
14、 % relativehumidity and tested under the conditions as described in Practice D1610.8. Procedure8.1 Determine the thickness of the specimen to the nearest 0.5 oz (0.20.001 in. (0.01 mm) on the long axis between the holeand the unsplit end of the specimen. The gage foot shall be adjacent to, but shall
15、 not overlap, the hole.8.2 Clamp one of the tongues on the specimen in each of the testing grips so that the long axis of the tongue is in the directionof the motion of the movable grip. The faces of the grips shall be approximately 2 in. (50.8 mm) from the common base of thetongues (from the hole).
16、8.3 Operate the machine at 10 6 2 in. (254 6 50.8 mm) per minute until the specimen starts to tear. At the instant of the initialtear, note and record the load registered by the machine.9. Report9.1 The thickness measurement of all specimens tested shall be averaged to the nearest 0.5 oz (0.20.001 i
17、n. (0.01 mm) andreported as the thickness of the sample.9.2 The load required to tear the specimens shall be averaged to the nearest pound and reported as the tongue tear strength ofthe sample.9.3 The direction of the long axis of the specimen relative to the backbone shall be reported.10. Precision
18、 and Bias (or Reproducibility)10.1 This test method is adopted from the procedures of the American Leather Chemists Association where it has long been inuse and where it was approved for publication before the inclusion of precision and bias statements was mandated. The originalinter-laboratory test
19、 data is no longer available. The user is cautioned to verify by the use of reference materials, if available, thatthe precision and bias (or reproducibility) of this test method is adequate for the contemplated use.FIG. 1 Test SpecimenD4704 12211. Keywords11.1 leather; tear strength; tearing streng
20、th; tongue tear; tongue tear strength; strengthASTM 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 any such patent rights,
21、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 are invited either for revi
22、sion 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 received a fair hearing you
23、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) 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/).D4704 123
