Patent ID: 6241840
Filing Date: 2001-06-05
Classification: B29C,B29K,B29L,B32B

Abstract:
A process foe continuously producing a glass-reinforced plastic potable water pipe with an ultra-thin thermoplastic inner layer and thermoset plastic outer shell, comprising the steps of:conveying, in a semi-molten or softened forms at least one thin film of thermoplastic material, onto a mandrel circumferentially and axially to the mandrel by a first application means to form an inner layer less than 1 mm thick comprising a coextruded multi-layer thermoplastic film comprising a polyethylene film together with a terpolymer film;contemporaneous with the application of said inner layer, applying a glass-reinforced thermoset plastic resin suitable for use as pipe shell laminate directly over the advancing inner layer circumferentially and axially to the mandrel and further along the mandrel, a second application means, thereby forming an outer layer which adheres to said inner layer;said outer and inner layer forming a completed pipe; andcuring the completed pipe as it is moved axially along the mandrel.