Method for the production of injection molding tools for the manufacture of plate-shaped blanks with fine-profiled surface,particularly cylinder lens screens,from thermo-plastics material

摘要

1,091,787. Making moulds &c. CHROMOWORKS Ltd. Nov. 9, 1964 [Nov. 7, 1963], No. 45557/64. Heading B3A. [Also in Division B5] In a method of making injection moulding tools for the manufacture, from thermoplastic material, of flat blanks with fine-profiled surface, the tool blank is subjected both on its working surface and on its opposite surface to embossing forces which are substantially equal in magnitude and opposite in direction. The tool blank is embossed on one surface by means of a profiled disc wheel with a trailing copying wheel in adjacent tracks and that surface is then covered with a removable protective layer while the second surface is similarly embossed.