Apparatus and process for high speed extrusion casting and products therefrom

摘要

A thermoplastic film 11 which has been extruded from a die 10 is passed round an internally cooled chilling roll 12, having a highly polished metal surface, and an idler roll 27, the film being passed after its first contact with roll 12 through the nip formed by roll 12 and a resilient pressure roll 13, and being cooled before contact with roll 13 by liquid maintained between the film and roll 13 at a level 15 lower than the point of first contact of the film with roll 12. The film may be of polyethylene, polypropylene, polybutene-1, polystyrene, nylon, or an acrylic or cellulosic polymer. The liquid may be water, alone or admixed with ethylene glycol, diethylene glycol or glycerine. Roll 12 may be of chromium, steel, or aluminium. Roll 13 may be of silicone rubber, neoprene, tetrafluoroethylene, or natural rubber.