초록 ▼

Method and apparatus for making multilayer injection molded plastic articles. In one embodiment, a relatively thin inner sleeve layer is molded in a first mold cavity on a core, the first mold cavity being heated to maintain an outer surface of the inner sleeve layer at an elevated temperature, and

Method and apparatus for making multilayer injection molded plastic articles. In one embodiment, a relatively thin inner sleeve layer is molded in a first mold cavity on a core, the first mold cavity being heated to maintain an outer surface of the inner sleeve layer at an elevated temperature, and the core and sleeve layer are transferred to a second mold cavity to mold a relatively thick outer layer over the sleeve layer while the outer surface is at the elevated temperature, where the elevated temperature is selected to provide melt adhesion between the inner sleeve and the outer layer during the second molding step. In another embodiment, a method of injection molding is provided in which a first thermoplastic material is used to form a first preform portion having an average percent crystallinity of at least about 30%, and a second thermoplastic material is injection molded to form a second preform portion which remains substantially amorphous.

대표청구항 ▼

1. Method of reducing the inner layer thickness and improving the layer adhesion in a multilayer injection-molded plastic article, the method comprising:molding a relatively thin inner sleeve layer (20) between a first mold cavity (11) and core (9), the first mold cavity being heated to maintain an

1. Method of reducing the inner layer thickness and improving the layer adhesion in a multilayer injection-molded plastic article, the method comprising:molding a relatively thin inner sleeve layer (20) between a first mold cavity (11) and core (9), the first mold cavity being heated to maintain an outer surface of the inner sleeve layer at an elevated temperature; transferring the core (9) and sleeve layer (20) to a second mold cavity (12) and molding a relatively thick outer layer (22) over the sleeve layer while the outer surface is at the elevated temperature, where the elevated temperature is selected to provide melt adhesion between the inner sleeve (20) and outer layer (22) during the second molding step.