Patent ID: 6143215
Filing Date: 2000-11-07
Classification: B29C

Abstract:
A method of molding an article comprising:(a) arranging first and second rigid hollow mold sections in a spaced apart opposed relationship;(b) defining a mold plenum between a first semi-rigid membrane attached to a side of said first hollow mold section and a second semi-rigid membrane attached to a side of said second hollow mold section adjacent said first semi-rigid membrane such that said first and second semi-rigid membranes are disposed opposite each other forming therebetween said mold plenum whenever said first and second hollow mold sections are closed together to mold articles;(c) filling said first and second rigid hollow mold sections with a substantially noncompressible backing fluid such that molding pressure produced in said mold plenum is transmitted from said first and second semi-rigid membranes to said first and second rigid hollow mold sections;(d) accommodating thermal expansion of said backing fluid by an expansion chamber in fluid communication with said first and second rigid hollow mold sections;(e) injecting molding fluid into said mold plenum to produce a molded part;(f) monitoring a flow rate at which said injecting molding fluid is carried out;(g) sensing at least one parameter indicative of said mold plenum filling with said molding fluid; and(h) controlling said flow rate responsive to said at least one parameter.