Method and apparatus for extruding a thermoplastic polymer of predetermined cross-sectional shape onto an article

摘要

During the extrusion of a sized (gauged) strip made of a thermoplastic, interruptions in the flow of molten material produce thickness non-uniformities in the profiled strip. The method of the invention provides for keeping a constant flow of molten material between the extruder (17) and the extrusion head (6). The device includes a three-way valve (30) which progressively directs the flow of molten material to a drain channel (35) when the extrusion head (6) stops. IMAGE