Method for the manufacturing of a multicolour thermoplastic film and apparatus for carrying out the method

• Main Authors: BARGIEL, LOTHAR, EYSEL, KONRAD
• Format: Patent
• Language: English; French; German
• Published: 09.07.1997
• Edition: 6
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULARARTICLES; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

For the prodn. of a multi-coloured thermoplastic film material, the screw press (22) has an additional feed of colouring matter (32). While being thoroughly mixed with the basic plastics material (16), it is forced through the sieve disc (36). The emerging material is passed through a calender roller assembly to be shaped into the required film thickness by the successive calender rollers. The temp. rise and fall are unequal to give flowing colour extended zones and colour transits in the material movement direction. Pref. the material flow (40) from the sieve disc (36) passes in a serpentine path swinging through the first two calender rollers. The colourant (32) is fed unevenly into the system with a vol. or gravimetric dosing. The colourant (32) is a paste, granules, powder or a combination. The granulate colourant (32) can be as fibres, colour clumps, concentrated colour balls or metallic powder or a combination of two or more types. The colourants are fed separately or mixed, with the mixing effected thoroughly from one or more supplies before feeding to the screw press.