Patent ID: 8021587

Claim:
A method of sequentially delivering multiple shots of polymer material to a plurality of mold cavities to form injection-molded multilayer articles, each cavity having a gate through which the multiple shots are delivered, the method comprising: delivering a first shot of a first material for forming an exterior layer of greater than 50% of a total weight of the multilayer article simultaneously to a plurality of mold cavities using, at each cavity, a chamber that is pre-filled with a volume of the first polymer material to deliver the pre-filled volume of the first material separately to each mold cavity; delivering a second shot of a second material for forming an interior layer comprising up to 10% of the total weight of the multilayer article simultaneously to all of the cavities beginning subsequent to the start of the first shot delivery step; and delivering one or more additional shots of a material to form the multilayer article; wherein the second material is injected directly to the mold cavities under pressure exerted by a common source of the second material to all of the plurality of cavities without the use of separate pre-filled chambers of the second material.