Patent ID: 6733714
Filing Date: 2004-05-11
Classification: B29C,B29K,Y10T

Abstract:
A method for forming a sheet of polymeric material, comprising the steps of:heating the sheet to a first temperature wherein the sheet is heated past a glass transition temperature and said sheet achieves a glass transition state; terminating heating of said sheet prior to placing in first and second mold halves; retaining the sheet between first and second mold halves of a forming mold with the sheet supported along a peripheral edge of one of said first and second mold halves; generating a vacuum on one side of the sheet thereby drawing the sheet into an interior space of one of said first and second mold halves while a center portion of the sheet remains supported in space relationship to said first and second mold halves; and cooling the sheet from said first temperature to a second temperature upon achieving a specified draw depth of the sheet within one of said first and second mold halves.