| 摘要 |
<p>Nozzle for fitting into the inner wall of a steam-heated mould for forming expansible or pre-expanded plastics particles, is a long as the wall is thick, and that surface pointing towards the mould cavity is completely closed, with the exception of gas inlets. Accumulation of condensed water ('puddles') at the bottom of the mould or entrainment of water into the mould cavity is minimised. This substantially reduces prodn. of inferior mouldings and reject rate. The nozzle consists of a solid body with perforations for gas inlets. Pref. it is a porous, sintered or felt-like nody. It may be designated as a pot-shaped body, known per se, with open-work bottom, with an inlet fitted into the space defined by the nozzle. The interior of the pot-shaped nozzle may be widened, with a shoulder at the end, enabling the in set to be fitted. The inset may be made of a plastics or metal, provided with holes, or it may be a plug of felted or sintered material.</p> |
