Patent ID: 6576170
Filing Date: 2003-06-10
Classification: B29C,B29K

Abstract:
A method of forming a hollow article of thermosetting polymer, said method comprising:(a) introducing thermosetting polymer into a mold to fill said mold, (b) subsequent to step (a), waiting a predetermined length of time sufficient to permit the thermosetting polymer to polymerize along the wall of the mold sufficiently to form a wall of said article of desired thickness, (c) subsequent to step (b), injecting a gas under pressure into said mold at a point at the end of flow of said thermosetting polymer in said mold to eject from said mold through the point at which the thermosetting polymer had been introduced into said mold the central portion of said thermosetting polymer that has not yet polymerized, thereby leaving in the mold a hollow molded article, (d) relieving pressure from the interior of said mold, (e) opening said mold and removing therefrom the hollow molded article.