1.1 本试验方法包括测定商用变形纱、包覆弹性纱和其他使用骨架的弹性纱的可恢复弹性。本试验方法对于暴露在湿热条件下产生额外卷曲的纱线特别有用。可恢复弹性是纱线在成品织物中预期提供的恢复力的相对度量。 1.2 本试验方法适用于连续长丝纱线，并适用于暴露在热环境中产生额外拉伸电位的纱线。 1.3 该方法适用于500旦或更细的纱线。 1.4 以国际单位制表示的数值应视为标准值。括号中给出的值仅供参考。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 由于目前实验室间精度的估计值是可接受的，并且该方法在验收测试行业中广泛使用，因此该测试方法被认为适合于商业装运的验收测试。 5.1.1 如果两个实验室（或更多实验室）的报告测试结果之间存在实际意义上的差异，则应进行比较测试，以确定它们之间是否存在统计偏差，并使用适当的统计协助。作为最低要求，使用尽可能同质的样品进行比较试验，从与初始试验期间产生不同结果的样品相同批次的材料中提取，并随机等份分配给每个实验室。 应使用未配对数据的统计测试，在测试系列之前选择的概率水平上，对相关实验室的测试结果进行比较。如果发现偏差，必须找到并纠正其原因，或者考虑到已知偏差，必须调整该材料的未来测试结果。 5.2 该试验不同于其他卷曲收缩试验方法，因为它测量纱线卸载循环期间的可恢复拉伸。

1.1 This test method covers the determination of the recoverable stretch of commercial textured yarns, covered elastomeric yarns and other stretch yarns using skeins. This test method is particularly valuable for yarns that develop additional crimp upon exposure to hot, wet conditions. The recoverable stretch is a relative measure of the recovery power the yarn can be expected to provide in a finished fabric. 1.2 This test method is applicable to continuous filament yarns and is suitable for yarns that develop additional stretch potential upon exposure to heat. 1.3 This method is applicable to yarns 500 denier or finer. 1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information only. 1.5 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. 1.6 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. ====== Significance And Use ====== 5.1 This test method is considered satisfactory for acceptance testing of commercial shipments because current estimates of between-laboratory precision are acceptable and the method is used extensively in the trade for acceptance testing. 5.1.1 If there are differences of practical significance between reported test results for two laboratories (or more), comparative tests should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, use samples for such comparative tests that are as homogeneous as possible, drawn from the same lot of material as the samples that resulted in disparate results during initial testing, and randomly assigned in equal numbers to each laboratory. The test results from the laboratories involved should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If bias is found, either its cause must be found and corrected, or future test results for that material must be adjusted in consideration of the known bias. 5.2 This test differs from other crimp contraction test methods in that it measures the recoverable stretch during the unload cycle of the yarn.