1.1 本试验方法描述了M.I.T.型折叠装置用于测定纸张和塑料薄膜的耐折叠性。M.I.T.测试仪可以针对任何厚度的样品进行调整；但是，如果外层厚度超过约0.25 mm（0.01 in.）在最初的几次折叠中破裂，测试失去了意义。试验方法中给出了Schopper型装置的程序 D643 . 1.2 以国际单位制表示的数值应视为标准值。括号中给出的值是英寸-磅单位的数学转换，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====== 4.1 折叠耐久性通常用于评估纸张和塑料薄膜承受反复弯曲、折叠和折痕的能力。 4.2 折叠式耐久性在测量纸张和塑料薄膜老化时的劣化方面也很有用。

1.1 This test method describes the use of the M.I.T.-type folding apparatus for determining folding endurance of paper and plastics film. The M.I.T. tester can be adjusted for samples of any thickness; however, if the outer layers thicker than about 0.25 mm (0.01 in.) rupture during the first few folds, the test loses its significance. The procedure for the Schopper-type apparatus is given in Test Method D643 . 1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound 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 ====== 4.1 The folding endurance is frequently used to estimate the ability of the paper and plastics film to withstand repeated bending, folding, and creasing. 4.2 Folding endurance has also been found useful in measuring the deterioration of paper and plastics film upon aging.