ČSN EN ISO 21306-2

This document specifies the methods of preparation of test specimens and the test methods to be used in determining the properties of PVC-U moulding and extrusion materials. Requirements for handling test materials and for conditioning both the test material before moulding and the specimens before testing are given. The properties required for the designation of PVC-U thermoplastics are given in ISO 21306-1. All properties are intended to be determined by the appropriate methods referred to in this document and values obtained shall be presented as laid down in ISO 10350-1. The values determined in accordance with this document are not necessarily be identical to those obtained using specimens of different dimensions and/or prepared by different procedures. The values obtained for the properties of a moulding depend on the moulding compound, the shape, the test method and the state of anisotropy. The last-mentioned depends on the gating of the mould and the moulding conditions, for example temperature, pressure and injection rate. Any subsequent treatment is also be considered, for example conditioning or annealing. The thermal history and the internal stresses of the specimens can strongly influence the thermal and mechanical properties and the resistance to environmental stress cracking, but exert less effect on the electrical properties, which depend mainly on the chemical composition of the moulding compound. In order to obtain reproducible and comparable test results, the methods of preparation and conditioning, the specimen dimensions and the test procedures specified herein are used. Values determined are not necessarily be identical to those obtained using specimens of different dimensions or prepared using different procedures.