Method for rotational moulding of a workpiece comprising a thermoplastic foam layer

摘要

A foam layer is formed by rotomoulding including heating a foaming polymer, and wherein the heating is interrupted before the foaming temperature is reached. A thermal inertia of the system also composed of the mold and previously placed layers assures completion of heating, but not sufficient to cause disorderly foaming. The foam layer is uniform and bonding. Dense layers surrounding the foam layer may be different.