1.1 本试验方法旨在测量在规定工艺条件下通过压缩或注射工艺成型时，热塑性塑料从模腔到成型尺寸的收缩率。 1.2 本试验方法涵盖24小时和48小时的收缩测量。 1.3 该方法将提供基于标准试样的可比数据，并且无法预测具有不同流动路径、壁厚、压力和温度梯度以及工艺条件的实际模制零件中的绝对值。本试验方法中描述的三种试样几何形状之间也可能观察到模具收缩的差异。 1.4 以国际单位制表示的数值应视为标准。括号中给出的值仅供参考。 1.5 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。 注1: 本标准和ISO 294-3在试样D2的设计中等效。本试验方法等同于ISO 294-4，其中D2型试样和程序 附录X2 使用。 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《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 注塑成型- 在注射成型中，模具型腔和模制样品的尺寸之间的差异可能因模具设计和成型过程的操作而异。众所周知，模具和熔体温度、填充时间和包装条件等因素会显著影响收缩率。遵守规定的模具设计（参见 7.1 )以及实践中概述的规范 D3641 或ISO 294-4或适当的材料规范将提高试验的再现性。 5.2 压缩成型- 在压缩成型中，模具型腔和模制样本的尺寸之间的差异可能会因模具设计和成型过程的操作而异。 众所周知，材料用量、冷却时间和压力应用等因素会显著影响收缩。遵守规定的模具设计（参见 7.2 )以及实践中概述的规范 D4703 或ISO 293或适当的材料规范将提高试验的再现性。

1.1 This test method is intended to measure shrinkage from mold cavity to molded dimensions of thermoplastics when molded by compression or injection processes with specified process conditions. 1.2 This test method covers shrinkage measurements at 24 and 48 hours. 1.3 This method will give comparable data based on standard specimens and can not predict absolute values in actual molded parts with varying flow paths, wall thicknesses, pressure and temperature gradients and process conditions. Differences in mold shrinkage may also be observed among the three specimen geometries described in this test method. 1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are given 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. Note 1: This standard and ISO 294-3 are equivalent in the design of specimen D2. This test method is equivalent to ISO 294-4 where Type D2 specimens and the procedure in Appendix X2 are used. 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 Injection Molding— In injection molding, the difference between the dimensions of a mold cavity and of the molded specimen may vary according to the design of the mold and operation of the molding process. Factors such as mold and melt temperature, fill times, and packing conditions are known to affect shrinkage significantly. Adherence to the specified mold design (see 7.1 ) and specifications outlined in Practice D3641 or ISO 294-4 or the appropriate material specification will improve the reproducibility of the test. 5.2 Compression Molding— In compression molding, the difference between the dimensions of a mold cavity and of the molded specimen may vary according to the design of the mold and operation of the molding process. Factors, such as the amount of material in charge, cooling time, and pressure application are known to affect shrinkage significantly. Adherence to the specified mold design (see 7.2 ) and specifications outlined in Practice D4703 or ISO 293 or the appropriate material specifications will improve the reproducibility of the test.