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. 25, 1995
Filed:
Dec. 22, 1992
Gregory P Weeks, Hockessin, DE (US);
Akhileswar G Vaidyanathan, Hockessin, DE (US);
Michael J Merrill, New Castle, DE (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
A method for determining the quality of dispersion of glass fibers in a thermoplastic resin preform layer compares the mean characteristic length of the glass fiber bundles in the preform layer to a predetermined value indicative of dispersion of the glass fibers. The thermoplastic resin preform layer characterized by this method comprises a plurality of individual glass fibers and some degree of undispersed glass fiber bundles intimately mixed with a plurality of discrete thermoplastic fibers. The glass fibers are introduced to the mixture having a length of about 1 cm. to about 8 cm. After mixing, some of the glass fiber bundles break up, and some residual glass fiber bundles remain. A preform layer which has acceptable dispersion has residual glass fiber bundles having a mean apparent length of less about 1.365 mm.