【国外标准】 Standard Test Method for Cracking Resistance of Leather

5.1 This test method is designed 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 other anchoring device, folded over in seams or welts, and so forth. The cracking resistance of leather is influenced by many factors such as 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 forth. This test method is useful for manufacturing control in the tannery, specification acceptance, and quality control in the end product manufacturing plant.1.1 This test method covers the determination of the resistance of leather to cracking when the leather is bent or folded with the 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, vise, and so forth) or by hand. Lighter leathers (for example, shoe upper, upholstery, garment, glove, and so forth) are usually given a sharp double-fold (crosswise) bend after 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 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 responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.