Patent ID: 8597020
Filing Date: 2013-12-03
Classification: B29B,B29C,B29K

Abstract:
1. An injection molding apparatus for sequential delivery of multiple shots of polymer material to a plurality of mold cavities to form multilayer articles, the apparatus comprising: a plurality of mold cavities, each mold cavity fluidly communicating with a first, a second and a third fluid delivery channel configured to respectively deliver first, second and third shots of polymer materials sequentially to each mold cavity; the first fluid delivery channel having separate channel portions each individually fluidly communicating with a corresponding mold cavity, wherein each channel portion has a separate fluid injection chamber that separately communicates with a corresponding mold cavity, each chamber configured to be pre-filled with a predetermined volume of a first polymer material of greater than 50% of a total weight of each multilayer article wherein each chamber simultaneously delivers the pre-determined volume of the first polymer-material during the first shot to each mold cavity; the second fluid delivery channel fluidly communicating with a common source of injection of a second material, the common source of injection configured to exert a pressure that simultaneously delivers to each of the plurality of mold cavities up to 10% of the total weight of the multilayer article as the second shot of the second material, wherein a delivery of the second shot by the common source to all of the plurality of mold cavities begins subsequent to a start of a delivery of the first shot to each mold cavity; the third fluid delivery channel fluidly communicating with each of the plurality of mold cavities for delivering the third shot of a third material to each of the mold cavities.