| 摘要 |
<p>In a rotational moulding process, in which for example a heated female mould is rotated about one axis and rocked about a perpendicular axis to spread the plastics material over its inner surface, a preformed member is suppported with the mould and embedded in the walls of the moulding during formation of the latter. As shown the preformed member is a membrane (33) supported by clamping between flanges (30) and (31) of mould halves and the drum moulding is formed in two parts (34 and 35) whose peripheral edges are bonded to the margin of the membrane. The membrane may be a temporary divider which is removed after completion of the moulding. It may be a permanent partition or a perforated sieve or strainer. The preformed member may alternatively be a structural member such as a strut to tie the walls against distortion by internal pressure. </p> |
