Over deze norm
This part of ISO 1872 specifies procedures for moulding test specimens of polyethylene materials under specified moulding conditions and methods for measuring their properties. No figures are quoted for these properties. Those required for the designation of polyethylene materials for moulding and extrusion are given in ISO 1872-1. Other properties are determined by the appropriate methods referred to in this part of ISO 1872 and values may be obtained from manufacturers' literature. Values should only be compared if the procedures described herein for preparing the test specimens and for determining the properties are followed. The values determined in accordance with this part of ISO 1872 will not necessarily be identical to those obtained using specimens of different dimensions and/or prepared by different procedures. They may also be influenced by colorants and other additives. 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 and the moulding conditions, for example temperature, pressure and injection rate. Any subsequent treatment must also be considered, for example conditioning or annealing. The thermal history and the internal stresses of the specimens may 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.
||Thermoplasten van polyetheen (PE) en van copolymeren met etheen - Deel 2: Bereiding van proefstukken en bepaling van eigenschappen
||Polyethylene (PE) and ethylene copolymer thermoplastics - Part 2: Preparation of test specimens and determinations of properties