ISO 20028-2:2017规定了试样的制备方法以及用于测定热塑性聚酯模塑和挤出材料性能的标准试验方法。给出了处理试验材料的要求，以及成型前试验材料和试验前试样的调节要求。 给出了在规定状态下制备试样的程序和条件，以及制备这些试样的材料的性能测量程序。列出了表征热塑性聚酯模塑和挤出材料的合适和必要的性能和试验方法。 这些性能是从ISO 10350-1中的一般测试方法中选择的。本文件还包括广泛使用的或对这些模塑和挤压材料具有特殊意义的其他试验方法，以及ISO 20028中规定的设计性能- 1（粘度数和拉伸弹性模量）。 为了获得可重复和可比较的试验结果，有必要使用本文规定的试样制备和调节方法、试样尺寸和试验程序。确定的值不一定与使用不同尺寸的试样或使用不同程序制备的试样获得的值相同。

ISO 20028-2:2017 specifies the methods of preparation of test specimens and the standard test methods to be used in determining the properties of thermoplastic polyester moulding and extrusion materials. Requirements for handling test material and for conditioning both the test material before moulding and the specimens before testing are given. Procedures and conditions for the preparation of test specimens in a specified state and procedures for measuring properties of the materials from which these specimens are made are given. Properties and test methods which are suitable and necessary to characterize thermoplastic polyester moulding and extrusion materials are listed. The properties have been selected from the general test methods in ISO 10350？1. Other test methods in wide use for or of particular significance to these moulding and extrusion materials are also included in this document, as are the designatory properties specified in ISO 20028-1 (viscosity number and tensile modulus of elasticity). In order to obtain reproducible and comparable test results, it is necessary to use the methods of specimen preparation and conditioning, the specimen dimensions and the test procedures specified herein. Values determined will not necessarily be identical to those obtained using specimens of different dimensions or prepared using different procedures.