A method and apparatus for the cyclical production of a deep-drawn workpieces made of thermoplastic plastic film

摘要

Deep drawn workpieces are produced from thermoplastic film by (a) initially drawing the film to a prepn. temp. lying below the deep drawing temp., (b) holding at this temp. until a special signal is provided, and then heating to the deep drawing temp., (c) drawing into the desired shape, and (d) cooling. Method enables the film to be heated rapidly and uniformly on both sides without fire risks or other difficulties. Productivity is increased. Prodn. of rejects is decreased.