Sleeve molding

摘要

A method of injection molding a multi-layer plastic article comprising: first molding an inner sleeve (20) on a core (9) positioned in a first mold cavity (11), the first molding step including a filling stage and a pressure boost stage but substantially no holding and cooling stage so as to maintain an outer surface of the inner sleeve at an elevated temperature for a second molding step; removing the sleeve (20) on the core (9) and transferring the same without substantial delay to a second mold cavity (12); and second molding an outer layer (22) over the sleeve (20) in the second mold cavity (12) to form the multi-layer injection molded article, wherein the elevated temperature of the outer surface promotes layer adhesion between the inner sleeve and outer layer.