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:
Feb. 29, 2000
Filed:
Nov. 20, 1996
James H Barron, Brazoria, TX (US);
James Entringer, Angleton, TX (US);
Randy S Moore, Lake Jackson, TX (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
An improvement in the preparation of fiber preforms in which binder and fibers are dispersed to contact on vacuum-supplied screens is disclosed, comprising particularly (a) selecting a particulate binder material which is solid at 25.degree. C; (b) heating the binder material, during initial contact with the fibers, to a viscosity and for a time which is the same as or proportional to 1,000 centipoise for one second; and (c) dispersing the binder material and the fibers such that the preform exhibits a variation in the ratio of fibers and binder which correlates to a coefficient of variation which is less than or equal to about 5 percent. The resulting preform shows superior compaction and uniformity of constitution even when it is prepared in sections or in asymmetric configurations. A wide variety of binders can be used, including thermoplastic and thermoset polymers, glasses, ceramics, metals, and the like, and the binder can also be selected from multi-component systems which are reactive with one another, such as epoxy-based systems, and/or reactive with a resin impregnant which may be subsequently introduced. In an alternative embodiment the preforms can be heated and pressed to make final composite articles, with or without direct application of a molding resin.