NF EN ISO 294-4

Le présent document prescrit une méthode pour la détermination du retrait au moulage du post-retrait des éprouvettes de matériau thermoplastique moulées par injection, dans les directions parallèle et normale au sens de l'écoulement du produit fondu.

This document specifies a method of determining the moulding shrinkage and post-moulding shrinkage of injection-moulded test specimens of thermoplastic material in the directions parallel to and normal to the direction of melt flow. For the determination of shrinkage of thermosets, see ISO 2577[2]. Moulding shrinkage as defined in this document excludes the effects of humidity uptake. This is included in post-moulding shrinkage and thus in total shrinkage. For cases when post-moulding shrinkage is caused by the uptake of humidity only, see ISO 175[1]. Moulding shrinkage as defined in this document represents the so-called free shrinkage with unrestricted deformation of the cooling plates in the mould during the hold period. It is considered, therefore, as the maximum value of any restricted shrinkage.