1.1 本试验方法包括测量在不同表面速度的拉伸辊对之间拉伸部分取向长丝时产生的拉伸力。 1.2 拉伸力提供了纱线取向的估计值。 1.3 本试验方法适用于小于33.3 tex（300旦尼尔）的部分取向长丝纱，但也可通过采用第 附录X1 . 1.4 以国际单位制表示的值应视为标准值。括号中给出的值仅供参考。 1.5 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前建立适当的安全、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《国际标准、指南和建议制定原则决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 5.1 该测试方法被认为对商业装运的验收测试是令人满意的，因为目前对实验室间精度的估计是可接受的，并且该方法在验收测试行业中被广泛使用。 5.1.1 如果两个实验室（或多个）的报告测试结果之间存在差异或实际意义，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，所使用的测试样本应尽可能均匀，从获得不同测试结果的材料中抽取，并随机分配给每个实验室进行测试。可使用具有既定试验值的其他材料。两个实验室的测试结果应使用未配对数据的统计测试进行比较，其概率水平应在测试系列之前选定。 如果发现偏差，必须找到并纠正其原因，或者必须考虑已知偏差调整未来的测试结果。 5.2 纺丝和测试之间的经过时间对拉伸张力测试的结果有显著影响，尤其是在前24小时。因此，如果在纺丝24小时内进行测试，则只有在经过相同的经过时间后进行测试时，才应比较试样。不应在纺纱后4小时内测试任何试样，因为在此期间老化过程速度最快，且纤维结构导致的速度差异最为明显。 5.3 制造的长丝的拉伸力与长丝中分子的排列有关，从而影响纱线加工行为。了解部分取向纱线的这种特性有助于确定加工条件。

1.1 This test method covers the measurement of extension force developed while drawing a partially oriented filament yarn between pairs of draw rolls of different surface speeds. 1.2 Extension force provides an estimate of the yarn orientation. 1.3 This test method applies to partially oriented filament yarns less than 33.3 tex (300 denier), but it can be used for higher deniers by applying the test conditions as directed in Appendix X1 . 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 or 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, the test samples to be used are as homogeneous as possible, are drawn from the material from which the disparate test results are obtained, and are assigned randomly 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 must be adjusted in consideration of the known bias. 5.2 Elapsed time between spinning and testing has a marked effect on the results of the draw tension test, especially during the first 24 h. Therefore, if tested within 24 h of spinning, specimens should be compared only if tested after the same elapsed time. No specimen should be tested within 4 h of spinning because the aging process is at its most rapid rate during this period, and the differences in rate due to fiber structure are most pronounced. 5.3 The extension force of manufactured filament yarns is related to the alignment of the molecules in the yarn filaments, which influences the yarn processing behavior. Knowledge of this property of partially oriented yarn is useful to determine processing conditions.