The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 28, 1992
Filed:
Oct. 31, 1990
James E Geary, Jr, Boothwyn, PA (US);
Gregory P Weeks, Hockessin, DE (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
A method of preparing porous fiber reinforced polymer composite sheets has been developed to allow a more efficient preheating of the sheet prior to molding and includes the steps of blending reinforcing fibers with resin matrix forming fibers to form a web. This web is then heated to a temperature wherein the resin matrix forming fibers melt and envelope the reinforcing fibers, taking them together at crossover points. The resultant web can then be directly heated very efficiently for molding. This web is highly porous allowing rapid heating at moderate pressure differentials during subsequent preheat steps. The microstructure created when the resin matrix forming fibers are initially melted further enhances heating capability because the structure retains porosity during the subsequent heating step required for molding. Because the resin matrix forming fibers initially were uniformly blended, a highly uniform distribution of polymeric material within the reinforcing fiber matrix yields molded parts with very uniform properties.