초록 ▼

A method and apparatus for runnerless injection molding of plastic materials utilizing a novel valve stem for controlling the opening and closing of at least two gates in a single injection nozzle The method and apparatus includes at least two separate melt streams whose flows are not obstructed by

A method and apparatus for runnerless injection molding of plastic materials utilizing a novel valve stem for controlling the opening and closing of at least two gates in a single injection nozzle The method and apparatus includes at least two separate melt streams whose flows are not obstructed by the valve stem. These melt streams may contain the same plastic material or different plastic materials and the injection nozzle may be either simultaneously or sequentially activated for filling the mold cavity.

대표청구항 ▼

[ What is claimed is:] [1.]1. A hot runner injection molding apparatus for co-injecting at least two plastic materials into a forming mold, comprising:a separate channel for each of said at least two plastic materials;a separate heating means for each of said separate channels;a separate gate for ea

[ What is claimed is:] [1.]1. A hot runner injection molding apparatus for co-injecting at least two plastic materials into a forming mold, comprising:a separate channel for each of said at least two plastic materials;a separate heating means for each of said separate channels;a separate gate for each of said at least two plastic materials, each said gate being in communication with a corresponding one of said channels and providing direct entry into the forming mold;a valve stem movable between a first position wherein each said separate gate is open and a second position wherein each said separate gate is closed; anda protrusion to separate each said separate gate from each other said separate gate, said protrusion cooperating with said valve stem to inhibit deflection thereof.