1.1 本试验方法涵盖了测量纱线和帘线在空气中的热收缩力的准备和程序。 1.2 本试验方法适用于测量收缩力为180±2的纱线和帘线的热收缩力 °C（355±4 °F）在空气中不超过20 N（4 lbf）。本试验方法适用于热收缩力适用范围内的尼龙、聚酯和芳纶纱线和帘线，以及其他聚合物的类似纱线和帘线。 1.2.1 试样可以从纱线或帘线包装中提取，也可以从织物中提取。 1.3 以国际单位制表示的数值应视为标准值。国际单位制后括号中给出的值仅供参考，不被视为标准值。 1.4 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。 具体危害说明见第节 8. . 1.5 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 本试验方法可用于商业运输的纱线和帘线的验收试验。 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。至少，应使用尽可能均匀的测试样品，从获得不同测试结果的材料中提取，并以相同数量随机分配给每个实验室进行测试。 具有既定测试值的其他材料可用于此目的。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，比较两个实验室的测试结果。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 经验表明，包装上的纱线或绳索通常处于张力下，当从包装中取出并在室温下松弛一段时间时，其长度会收缩（并导致线密度增加）。因此，如果在不允许松弛的情况下对其进行测试，它们将记录更高的热收缩力值，因为松弛收缩将被错误地包括在热收缩力中。 5.2.1 缩回力因聚合物类型而异，在芳纶中几乎为零，在大多数尼龙中显著。 例如，将未拉伸的尼龙纱线或绳索骨架暴露在95到100之间 % 在室温下保持两天的相对湿度，并在标准实验室条件下重新调节，将导致样品内发生室温下可能发生的大部分长度变化。长度的减少伴随着热收缩力的降低。 5.3 尼龙、聚酯和芳纶纤维的热收缩力与来源聚合物及其加工操作有关。热收缩力测量可用于控制产品均匀性。 5.4 热收缩力的水平在用户的后续操作中至关重要，例如制造特定尺寸轮胎所需的卷筒组（帘线的原始长度）。 5.5 热收缩力对纤维增强制品的最终形状和尺寸至关重要。例如，热收缩力影响V的最终尺寸- 皮带及其在运行期间保持张力的能力。 5.6 本试验方法与试验方法的标称程序一致 D885/D885M 用于测定纱线和帘线的热收缩力。 5.6.1 当试样在规定温度下放置在烘箱内，经过规定时间后，测量收缩力。

1.1 This test method covers preparation and procedures to measure the thermal shrinkage force of yarns and cords in air. 1.2 This test method is applicable to measurement of the thermal shrinkage force of yarns and cords whose shrinkage force at 180 ± 2 °C (355 ± 4 °F) in air does not exceed 20 N (4 lbf). This test method is applicable to nylon, polyester, and aramid yarns and cords within the applicable range of thermal shrinkage force, as well as to comparable yarns and cords from other polymers. 1.2.1 Test specimens may be taken from yarn or cord packages, or retrieved from fabrics. 1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.4 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. Specific hazards statements are given in Section 8 . 1.5 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 may be used for the acceptance testing of commercial shipments of yarns and cords. 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, test samples should be used that are as homogeneous as possible, that are drawn from the material from which the disparate test results were obtained, and that are randomly assigned in equal numbers to each laboratory for testing. Other materials with established test values may be used for this purpose. The test results from the two laboratories should be compared using a statistical test for unpaired data, at a probability level chosen prior to the testing series. If a 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 Experience shows that yarns or cords on would packages, usually being under tension, exhibit a contraction in length (and a resulting increase in linear density) when removed from the package and allowed to relax over a period of time at room temperature. Consequently, it they are tested without being allowed to relax, they will register higher thermal shrinkage force values as the relaxation shrinkage will be incorrectly included as the thermal shrinkage force. 5.2.1 Retractive forces vary widely by polymer type, being almost nil within aramids and significant within most nylons. For example, the exposure of untensioned skeins of nylon yarn or cord to 95 to 100 % relative humidity at room temperature for two days and reconditioning under standard laboratory conditions will cause most of the length change that is possible at room temperature to occur within a sample. This reduction in length is accompanied by some lowering of thermal shrinkage force. 5.3 The thermal shrinkage force of nylon, polyester, and aramid fiber is related to the polymer of origin and its manipulation in processing. Thermal shrinkage force measurement can be used to control product uniformity. 5.4 The level of thermal shrinkage force is critical in the user's subsequent operations, such as the drum-set (original length of cord) required to build a tire of a particular size. 5.5 The thermal shrinkage force is critical to the final shape and size of fiber-reinforced articles. For example, thermal shrinkage force affects the final size of V-belts and their ability to maintain tension during their operation. 5.6 This test method is in agreement with the nominal procedures of Test Methods D885/D885M for the determination of thermal shrinkage force in yarns and cords. 5.6.1 Shrinkage force is measured while the specimen is within an oven at a specified temperature and after a specified length of time.