Equipment to mould thermoplastic film - has top ram which presses moulding tool plus preheated film on top of membrane lying on enclosed bulky mass of elastic material

摘要

A set-up to mould (in particular) films over three-dimensional mouldings has a pressure space partly filled with an elastic material and closed off by a ram which advances to compress the space. The elastic material is now compressed but unable to escape and therefore fills the space plus the moulding and gaps present; it also moulds the film between the moulding and elastic material. The top ram (1) of the press closes within the sides (2) to apply its hydraulic pressure, these sides (2) being attached to the base plate (3) to withstand that pressure. A membrane (4) is placed on top of the mass of elastic material (6). The film (7) to be thermoformed is placed on the membrane (4) and the appropriate moulding (5) on the assembly. The ram (1) is lowered and presses the flat top face of the moulding (5), whilst the film (7) is moulded to its underside. The pressure needed is 10 bars max. The membrane (4) is heated first and allowed to cool in the assembly. Total pressing times required are only 1-2 minutes. ADVANTAGE - The arrangement eliminates dangers to operators. It shortens the heating and cooling times required when working with thermoplastic films. It produces high grade articles.