Patent ID: 6287491
Filing Date: 2001-09-11
Classification: B29B,B29C,B29K,B29L

Abstract:
In a method of molding plastics articles, each said article having at least one predetermined part of a different composition from the remainder of the article, the method comprising introducing a solid plastics feed material into a screw feed means and rotating said screw feed means to propel said feed material through a melting zone, propelling the resultant molten plastics material to shaping means, shaping the molten plastics material in the shaping means and allowing the material to solidify to retain the shape, wherein the composition of the material entering the shaping means is varied cyclically, the improvement comprising monitoring the movement of the screw feed means and controlling the introduction of different feed materials into said screw feed means according to the instantaneous monitored position of said screw feed means so as to vary the composition of the plastics feed material cyclically at a position remote from the shaping means, whereby the composition of the material entering the shaping means is controlled to form said at least one predetermined part of the molded article of different composition from the remainder of the article.