1.1 本试验方法涵盖了用于制造绒线地板覆盖物的机织物、针织物和非织造背衬织物在潮湿和干燥条件下的收缩率评估程序。地毯衬垫收缩率的测定先前包含在试验方法中 D2646 . 为了一致性，小组委员会D13.21提取了这一部分，并创建了一个单独的测试方法。 1.2 以英寸-磅为单位的数值应视为标准值。括号中给出的值是到国际单位制的数学转换，仅供参考，不被视为标准值。 1.3 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。 1.4 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 该测试方法可用于表征和比较主要和次要背衬织物的收缩性能。由于实验室间精度的当前估计值是可接受的，并且该测试方法在验收测试行业中普遍使用，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，并使用适当的统计辅助。 作为最低要求，在此类比较试验中使用尽可能同质的测试样品，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，并以相同数量随机分配给每个实验室进行测试。实验室的测试结果应在测试系列之前选择的概率水平上，使用未配对数据的统计测试进行比较。如果发现偏差，则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。

1.1 This test method covers the procedure for evaluating shrinkage, in both wet and dry conditions, of woven, knitted and nonwoven backing fabrics designed for use in the manufacture of pile yarn floor coverings. Determination of carpet backing shrinkage was previously contained within Test Methods D2646 . For consistency, Subcommittee D13.21 extracted this portion and created a separate test method. 1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 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. ====== Significance And Use ====== 5.1 This test method can be useful in characterizing and comparing shrinkage properties of both primary and secondary backing fabrics. This test method is considered satisfactory for acceptance testing of commercial shipments because current estimates of between-laboratory precision are acceptable, and this test method is commonly used 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 statistical bias between them using competent statistical assistance. As a minimum, use test samples for such comparative tests that are as homogeneous as possible, drawn from the same lot of material as the samples that resulted in the disparate results during initial testing, and that are randomly assigned in equal numbers to each laboratory for testing. The test results from the laboratories should be compared using 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.