1.1 本试验方法确定了螺纹塑料密封件对环境应力开裂（ESC）引起的失效的敏感性。 1.2 在使用中，螺纹塑料密封件可以接触到明显降低裂纹形成应力的介质。例如:肥皂、洗涤剂、油和液体漂白剂。 1.3 影响螺纹塑料密封件环境应力抗裂性（ESCR）的主要因素包括密封件材料、密封件设计、模压应力和施加应力。 1.4 该程序可适用于所有密封件，但特别适用于由聚丙烯（PP）或聚苯乙烯（PS）塑料制成的密封件。 1.5 以英寸-磅为单位的数值应视为标准值。 括号中给出的值仅供参考。 1.6 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。 第节给出了具体的预防说明 8. 和 6.2 . 注1: 没有已知的ISO等效于本标准。 1.7 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 该测试方法比较了ESCR的闭包。合适的变量包括:闭合材料、闭合设计、工艺、施加扭矩和应力裂纹剂。 5.2 结果可用于根据ESCR估算封口的保质期。这要求用户将本测试中的故障时间校准为实际包装系统的现场故障时间。

1.1 This test method determines the susceptibility of threaded plastic closures to failure due to environmental stress cracking (ESC). 1.2 In use, threaded plastic closures can contact agents that appreciably reduce the stress at which cracks form. Examples of such agents are: soaps, detergents, oils, and liquid bleaches. 1.3 Major factors that influence environmental stress crack resistance (ESCR) of threaded plastic closures include the closure material(s), closure design, molded-in stress, and applied stress. 1.4 This procedure can be applied to all closures, but is particularly applicable to closures made from plastics based on polypropylene (PP) or polystyrene (PS). 1.5 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only. 1.6 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 precautionary statements are given in Section 8 and 6.2 . Note 1: There is no known ISO equivalent to this standard. 1.7 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 compares closures for ESCR. Suitable variables are: closure materials, closure designs, processes, applied torque, and stress-crack agents. 5.2 Results can be used for estimating shelf life of closures in terms of ESCR. This requires that the user has calibrated failure time in this test to failure time in the field for actual packaging systems.