1.1 本试验方法包括测定由橡胶、氨纶或其他弹性体制成的“生产”弹性纱线的弹性性能。弹性特性包括指定伸长处的力、永久变形和应力衰减。可以计算其他与磁滞相关的特性。 注1: 有关专门为测试橡胶螺纹而设计的方法，请参阅测试方法 D2433 . 1.2 本试验方法不适用于包覆、包裹或包芯纱或由弹性短纤维纺成的纱线。 1.3 本试验方法适用于40至3200 dtex（36至2900旦）范围内的弹性纱线。 1.4 以国际单位制或美国惯用单位表示的数值应单独视为标准。在文本中，美国惯用单位在括号中。每个系统中规定的值不是精确的等价物；因此，每个系统应相互独立使用。 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 由于实验室间精度的当前估计值是可接受的，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用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 规定伸长力（FASE）是指在规定极限内拉伸纺织材料时产生的拉力。 弹性纱线的这一特性表明了穿着者在穿着由弹性纱线制成的服装时必须克服的阻力，同时也表明了服装在穿着过程中抵抗正常身体运动引起的变形的能力。用于这些测量的伸长率通常为100 %, 200 % 和300 %. 5.3 永久变形（set）是衡量弹性纱线长度因循环拉伸和松弛而增加的指标。该特征是弹性材料内分子间键重新排列的可见指示。随着应力衰减，凝固量随着纱线伸长而增加；然而，对于任何特定的伸展运动，在五个周期的运动后，很少或没有额外的运动。一般来说，纱线的特征组是在织物制备过程中形成的，织物本身的组分数量可以忽略不计。 5.4 应力衰减随纱线伸长而增加，但在任何指定伸长时，应力衰减发生在前30秒，5分钟后衰减不明显。这一特征是由弹性材料内分子间键的逐渐重新排列引起的，有助于解释伴随循环拉伸和松弛的纱线特性的变化。债券的重新调整是一种可逆效应。纱线完全松弛后，分子倾向于呈现其原始构型，几乎完全消除了先前观察到的应变。 5.5 本试验方法是在“生产”状态下使用弹性纱线开发的，但如果规定了处理方法，则可用于处理过的弹性纱线。该方法不包括为了测定“无整理”弹性纱线的弹性性能而去除整理剂。

1.1 This test method covers the determination of elastic properties of “as produced” elastomeric yarns made from rubber, spandex or other elastomers. Elastic properties include force at specified elongations, permanent deformation and stress decay. Other hysteresis related properties can be calculated. Note 1: For a method designed specifically for testing rubber threads, refer to Test Method D2433 . 1.2 This test method is not applicable to covered, wrapped, or core-spun yarns or yarns spun from elastomeric staple. 1.3 This test method is applicable to elastomeric yarns having a range of 40 to 3200 dtex (36 to 2900 denier). 1.4 The values stated in either SI units or U.S. Customary units are to be regarded separately as standard. Within the text, the U.S. Customary units are in parentheses. The values stated in each system are not exact equivalents; therefore, each system shall be used independently of the other. 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 since 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 Force at Specified Elongation (FASE) is a measure of the tensile force occurring while extending a textile material within specified limits. This characteristic of elastomeric yarn indicates the resistance that will have to be overcome by the wearer while putting on a garment made of the material and is also an indication of the garment's resistance to deformation caused by normal body movements during wear. The elongations used for these measurements are typically 100 %, 200 % and 300 %. 5.3 Permanent Deformation (set) is a measure of the increase in length of an elastomeric yarn resulting from cyclic stretching and relaxation. The characteristic is a visible indication of the realignment of intermolecular bonds within the elastic material. As with stress decay, the amount of set increases with yarn extension; however, for any particular extension, little or no additional set takes place after five cycles of exercising. Generally, the characteristic set of the yarn is developed during fabric preparation and the fabric itself shows a negligible amount of set. 5.4 Stress decay increases with yarn extension, but at any specified extension the stress decay takes place in the first 30 s with insignificant decay after 5 min. This characteristic is caused by the gradual realignment of intermolecular bonds within the elastic material, and helps to explain the changes in yarn properties that accompany cyclic stretching and relaxing. The realignment of the bonds is a reversible effect. Following complete relaxation of the yarn, the molecules tend to assume their original configuration with just about complete elimination of the previously observed strain. 5.5 This test method was developed using elastomeric yarns in the “as-produced” condition, but may be used for treated elastomeric yarns provided the treatment is specified. The method does not cover the removal of finish for the determination of elastic properties of “finish-free” elastomeric yarns.