| 摘要 |
<p>Rotational moulding of articles in thermoplastic material with a composite wall constituted by two thicknesses of moulded material and an intermediate filling, is carried out by pouring a divided material into the mould at a suitable moment during the moulding cycle, while the interior face of the two elementary thicknesses of the article is in a viscous state, so that the material is distributed over the interior face, thus providing a suitable superficial roughness to ensure the pick-up of the filling. The method ensures that a firm bond is obtained between the layers of thermoplastic material and the filling material, pref. cellular polyurethane.</p> |
