The Dow Chemical Company

Dow-united Technologies Composite Products, Inc.

Gkn Westland Aerospace, Inc.

Johnny P Gendreau

Warren D White

James H Barron

Brenda Thies Colegrove

Curt Goodwyn Wilkinson

Larry N Varholak

A preform suitable for use in a resin transfer molding process comprising (1) one or more layers of a non-woven random mat and (2) one or more layers of a series of tows of unidirectional fibers held together by a polymeric curable resin film grid. The polymeric resin film is in the form of a grid, such that only a fraction of the surface area of the fibers contacts the resin film.

Unidirectional fiber-random mat preform

An apparatus and method provide for the assembly of a multiply shaped fiber preform, the apparatus using a shaping tool having the shape of the desired part, and one or more secondary location tools, can be positioned on the shaping tool, so as to simulate a flat shape. The location tools include a number of upwardly extending location pins, such that a number of plies can be assembled in a vertical stack using the pins to assure ply to ply accuracy and orientation. After assembly, the plies are engaged in a localized portion of the assembly so as to hold the plies in register, with the secondary tools then removed and the plies then formed to shape over the tool surfaces. Utilizing the apparatus and method of the invention maintains multiple plies in register during the assembly and forming process to assure part reproducibility, in an automated process.

Method for precision preforming of complex composite articles

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

Growing community of inventors

Beacon Falls, CT, United States of America

Johnny P Gendreau