Patent ID: 6447627
Filing Date: 2002-09-10
Classification: B29C,Y10T

Abstract:
A process for manufacturing lightweight molded articles comprising the steps of:a) providing first and second mold halves with at least one mold half movable relative to the other towards a closed position whereat a mold cavity is produced to define the external shape of the article; b) providing a matrix layer adjacent one of said mold halves, said matrix layer selected from a molding material group consisting of plastics, cellulose, pulp and wood fiber; c) positioning a discrete, macro sized insert at a plurality of set locations on said matrix layer, each insert containing a substance that creates gas when activated; d) causing a molding material to be positioned between said mold halves and said insert when said mold halves have been moved into a position adjacent one another so that said inserts are in said mold halves and said molding material is between said mold halves and said inserts while said article is molded into a shape; and, e) activating said substance to create gas and moving said mold halves away from one another in a controlled manner to a set position whereat said gas can expand to form at each position of an insert an internal macro sized gas cavity whereby a configured hollow molded article is produced.