1、Designation: D6075 00 (Reapproved 2010)D6075 13Standard Test Method forCracking Resistance of Leather1This standard is issued under the fixed designation D6075; 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 resistance of leather to cracking when the leather is bent or folded withthe grain (or finish) surface on the outside of the bend. Heavy leathers (for example, harness, belt, strap, bag, case, and so forth)are usually bent around a mandrel using either mechanical resistance (for example, clamp, vi
4、se, and so forth) or by hand. Lighterleathers (for example, shoe upper, upholstery, garment, glove, and so forth) are usually given a sharp double-fold (crosswise) bendafter cooling to a low temperature. This test method does not apply to wet blue.1.2 The values stated in SI units are to be regarded
5、 as the standard. The values given in parentheses are for information only.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 and determin
6、e the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1517 Terminology Relating to LeatherD1610 Practice for Conditioning Leather and Leather Products for TestingD1813 Test Method for Measuring Thickness of Leather Test Specimens3. Terminology3.1 For d
7、efinitions of general leather terms used in this test method, refer to Terminology D1517.3.2 Definitions:3.2.1 finish crackingthe appearance of cracks (that is, ruptures) in the finish of leather which may extend through the finishlayer to the surface of the crust leather or deeper.3.2.2 grain crack
8、ingthe appearance of cracks (that is, ruptures of the grain enamel) on the grain surface of the leather whichmay even extend deeper into the leather cross section.4. Summary of Test Method4.1 A specimen of leather is conditioned and then bent by one of three procedures. The grain (or finish) surface
9、 of the bentspecimen is then examined for the appearance of any cracks or ruptures in the area around the bend.4.1.1 One bending procedure for heavier leathers involves a mandrel rod, a metal bar with thickness equal to the diameter ofthe mandrel, and a large clamp or vise to force and hold the leat
10、her in the bent configuration around the mandrel with the metalbar placed between the flesh surfaces of the bent leather.4.1.2 A second bending procedure for heavier leathers involves bending the leather around a mandrel by hand and forcing andholding the leather so the flesh surfaces of the bent le
11、ather are in contact.1 This test method is under the jurisdiction of ASTM Committee D31 on Leather and is the direct responsibility of Subcommittee D31.01 on Vegetable Leather. This testmethod is a combination of three methods (that is, Methods 4011, 4021, and 7211) that were part of Federal Test Me
12、thod Standard No. 311. This test method was developedin cooperation with the U.S. Defense Personnel Support Center, Directorate of Clothing and Textiles, Philadelphia, PAand the U.S.Army Natick Research, Development andEngineering Center Natick, MA.Current edition approved April 1, 2010May 1, 2013.
13、Published May 2010May 2013. Originally approved in 1997. Last previous edition approved in 20052010 asD6075 00 (2005).(2010). DOI: 10.1520/D6075-00R10.10.1520/D6075-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual
14、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 of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be tec
15、hnically 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 published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO
16、 Box C700, West Conshohocken, PA 19428-2959. United States14.1.3 A third bending procedure for lighter leathers involves cooling the leather specimen and then creating a sharp double(crosswise) fold while the specimen remains in the cold chamber.5. Significance and Use5.1 This test method is designe
17、d to determine the cracking resistance of the grain or finish surface of leather on a pass/fail basis.This test method attempts to replicate the conditions that may be encountered by leather that is bent around a buckle frame or otheranchoring device, folded over in seams or welts, and so forth. The
18、 cracking resistance of leather is influenced by many factors suchas quantity, location, and type of fatliquoring materials; moisture content; thickness; the presence of defects or scar tissue, or both;the presence of processing damages to the skin or hide tissue; finish system formulation, and so f
19、orth. This test method is usefulfor manufacturing control in the tannery, specification acceptance, and quality control in the end product manufacturing plant.6. Apparatus6.1 Vise or Clamp, shall have plain (that is, smooth and not knurled or roughened) jaws not less than 7 cm (234 in.) wide.6.2 Man
20、drel, shall be a rod approximately 15 cm (6 in.) in length and shall have a diameter as specified in the materialspecification.6.3 Metal Bar, shall be approximately 15 cm (6 in.) in length, 1.9 cm (34 in.) in width, and shall have a thickness equal to thediameter of the mandrel as specified in the m
21、aterial specification.6.4 Low-temperature Chamber, shall be capable of maintaining the required temperature (usually 0C) to within 6 1C andequipped so as to permit insertion of hands to hold and manipulate the leather specimen within the chamber.7. Test Specimens7.1 The test specimen for bending aro
22、und a mandrel shall be 150 mm (6 in.) long by 25 mm (1 in.) wide. The direction of thelong dimension relative to the backbone shall be noted.7.2 The test specimen for low-temperature double-folding shall be 50 6 2 mm (2 6 0.08 in.) square.7.3 All test specimens shall be free from mechanical damage a
23、nd defects.8. Conditioning8.1 Condition all specimens in accordance with Practice D1610. Conditioning other than that prescribed shall be noted in theresults.9. Procedure9.1 Determine the thickness of the specimen (in the area that will be bent) to the nearest 0.025 mm (0.001 in.). See Test MethodD2
24、813D1813.9.2 Vise- or Clamp-aided BendingBend the specimen into a loop with the grain or finish side of the leather out. Place themandrel of the specified diameter in the loop of the specimen. Place the metal bar having a thickness equal to the diameter of themandrel on top of the mandrel. Place the
25、 whole assembly in the vise with the loop downward as illustrated in Fig. 1. Bend thespecimen around the mandrel and against the bar by slowly closing the vise jaws until the mandrel and bar cannot be moved byhand. Examine the grain or finish side of the specimen for cracks in the area around the be
26、nd.9.3 Hand BendingBend the specimen slowly by hand over a mandrel of the specified diameter. Make the bend through anangle of 180 with the grain or finish side of the leather out. Examine the grain or finish side of the specimen for cracks in thearea around the bend.9.4 Low-temperature Bending:9.4.
27、1 Expose the conditioned specimen to a temperature of 0 6 1C for a period of 2 h 6 5 min, and then test at thattemperature. A testing temperature different than that prescribed shall be noted in the reported results.9.4.2 Place the specimen in the low-temperature chamber and maintain at the required
28、 temperature for the required period oftime. While remaining in the cold chamber at the specified temperature, fold the specimen crosswise sharply upon itself with thegrain or finish surface of the leather facing out. Then remove the folded specimen from the cold chamber and examine for cracksin the
29、 area around the double-fold bend.10. Report10.1 Report the following information:10.1.1 The presence or absence of any cracks in the specimen,10.1.2 The thickness of the leather specimen,10.1.3 If appropriate, the direction of the long dimension of the specimen relative to the backbone,10.1.4 If a
30、mandrel was used, the diameter of the mandrel, andD6075 13210.1.5 If a low-temperature chamber was used, the temperature at which the specimen was tested.11. Precision and Bias11.1 This test method is adopted from the Federal Test Method Standard No. 311, Methods 4011, 4021, and 7211. Thesemethods h
31、ave long been in use and were approved for publication before the inclusion of precision and bias statements wasmandated. The user is cautioned to verify by the use of reference materials, if available, that the precision and bias (orreproducibility) of this test method is adequate for the contempla
32、ted use.12. Keywords12.1 cracking; cracking resistance; finish cracking; grain cracking; leather; leather crackingASTM 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 adv
33、ised 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 by the responsible technical committee and must be reviewed every five years andif not revised, either
34、 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 receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If
35、 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 International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individ
36、ual 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/).FIG. 1 Leather Specimen Bent in ViseD6075 133
