Patent ID: 6533565
Filing Date: 2003-03-18
Classification: B29C

Abstract:
A die system for extruding plastic products, said plastic flowing through a passage constructed in a series of assembled modules and extending from upstream inlet to a downstream outlet, said products being formed in accordance with the cross section of the outlet of the system, said die system comprising:selected regions of said outlet cross section having predetermined flow concentration requirements; a distribution module having an inlet for receiving flowing plastic and a plurality of distribution channels for receiving a divided portion of said flowing plastic, each of said distribution channels constructed to supply one of said selected regions with said portion of the plastic flow; a transition module having a plurality of transition channels constructed therein to form a portion of the die system passage, each of said transition channels communicating with one of said distribution channels to receive flowing plastic therefrom, said transition channels constructed having a cross section which varies, from a first cross section, shaped to facilitate communication with said distribution channel, to a second cross section, shaped substantially in the form of one of said selected regions of said die system outlet cross section; a die module having an extrusion passage constructed therein to form a portion of the die system passage to receive flowing plastic from said transition channels and to extrude said plastic through its outlet to form the extruded product; and wherein said plastic flow in each of the distribution channels is determined by the ratio of the cross sectional area of the selected region supplied thereby, to the overall cross sectional area of the die system outlet.