Patent ID: 6146562
Filing Date: 2000-11-14
Classification: B29C

Abstract:
A method for the production of an injection molded article having a cellular density distribution whereby the cellular structure of said injection molded article varies gradually between a first cellular structure of high density and a second cellular structure of relatively lower density, said method comprising;a) providing a first mold section;b) providing a second mold section capable of seated engagement with said first mold section;c) forming a mold cavity by moving said first and said second mold sections into seated engagement;d) providing an injection means;e) injecting an injection mixture into said mold cavity through said injection means, wherein said injection mixture comprises a blowing agent;f) creating a first cellular density distribution by varying the injection rate of the injection mixture and the volume of said mold cavity according to a first predetermined control function, thereby producing said injection molded article having said cellular structure which varies gradually between said first cellular structure of high density and said second cellular structure of relatively lower density.