塑料.热塑性聚酯（TP）模塑和挤出材料.第2部分：试样的制备和性能的测定

[中文适用范围]： 本文件规定了热塑性聚酯注塑和挤出材料试样的制备方法以及测定其性能的标准试验方法。 [外文原描述]： 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.