The Dow Chemical Company

James H Barron

Warren D White

Ranganath K Shastri

Randy S Moore

Johnny P Gendreau

James Entringer

Alex N Kalos

John F Braley

Jean R Campestre

Nathan M Lacoff

Robert E Cramer

A computer implemented knowledge-based system for the selection of materials and/or fabrication processes for a durable goods application. The system consists of a graphical user interface, an expert system shell and a models and data base program. The system provides rapid, consistent and accurate techno-economic comparisons of processes and materials to select the best materials and fabrication processes for the durable goods application.

Processes and materials selection knowledge-based system

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.

Method for making preforms

A process for preparing a matrix resin composite contains the steps of: (1) preparing a preform containing multiple layer of reinforcing material and a crosslinkable tackifier by (a) applying the tackifier onto the reinforcing material, (b) compressing the layers of reinforcing material and partially crosslinking the tackifier under a pressure sufficient to compact the tackified, reinforcing layers to a volume which is less than their volume in the finished composite part and in a manner such that at least one surface of each of the reinforcing layers is or will be, during partially crosslinking, in direct contact with the tackifier, and (2) contacting the preform with a matrix resin.

Process for preparing a resin matrix composite using a preform

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Brazoria, TX, United States of America

James H Barron