United Technologies Corporation

Gary J Jacaruso

Geoffrey C Davis

Allen J McIntire

Philip J Ramey

Darryl Mark Toni

Edward Joseph Fabian

Alexander C Dublinski

Peter B Leoni

Ronald J Cooper

Matthew T Turner

A heating element for providing localized heating during the thermoplastic bonding of thermoset composite structures is disclosed. Various construction details are developed which disclose an apparatus and method for uniformly heating a bond line. In one embodiment, a heating element (22) includes a resistance heating material (24) sandwiched between two layers of electrical insulation (25) and encased within a layer of thermoplastic material (26). Low resistance electrical leads (28), which extend across the width of the resistance heating material, and a power supply (30) provide electrical energy to raise the temperature of the resistance heating material.

Heating means for thermoplastic bonding

A composite forming tool is fabricated by securing shapeable filler blocks between composite headers and contouring the blocks to match the shape of the headers, to form a support structure with a continuous surface. Layers of uncured, composite laminates are laid up over the support structure and cured. The filler blocks may be removed after curing.

Method for fabricating a composite structure

A pair of thermoset composite structures (19,19') are bonded together by a pair of adhesive strips (10,10'). An adhesive strip (10) is comprised of a layer of semi-crystalline thermoplastic material (12), a layer of amorphous thermoplastic material (14), a layer of dry fiber reinforcement (16) partially embedded in the layer of amorphous thermoplastic material (14), and a layer of thermosetting resin (18) covering the exposed fibers of the dry fiber reinforcement. An adhesive strip is bonded to the bonding surface (20) of the structure (19) during the curing process for the thermoset composite structure. A resistance heating element is placed between the bonding surfaces (20,20'), the bonding surfaces (20,20') are pressed together, and electrical energy is passed through the heating element (24) to heat the joint and fuse the thermoplastic adhesive layers together. The dry fiber reinforcement (16) forms a mechanical lock between the cumulative layer of thermoplastic adhesive (32) and the thermosetting structures (19,19') to provide the bond strength.

Bonding of thermoset composite structures

The method of fabricating a complex part made of composite material and having a plurality of panels oriented in diverse angular relationship, and utilizing a plurality of conformable cauls upon which the composite material is individually laid up and which cauls cooperate to form one of the molds used in the co-curing of the individually laid-up composite materials.

Method of fabricating a complex part made of composite material

Method of making thermoplastic adhesive strip for bonding thermoset

A method of making tubular composite structures that simplifies vacuum bag sealing. The method comprises disposing a prepreg structure within a tool that has at least one hole. The prepreg is disposed adjacent a mandrel. The mandrel comprises an inner bag containing a solid filler core that comprises about 75% to about 95% of the volume of the inner bag. The hole is enclosed with a vacuum bag thereby forming a void space between said vacuum bag and said prepreg. The void space is evacuated. The vacuum bag applies a predetermined pressure to the inner bag thus causing the inner bag to apply a substantially uniform predetermined pressure to the surface of the prepreg. The prepreg is exposed to heat.

Method of fabricating tubular composite structures

A method of stabilizing thick honeycomb core composites is disclosed. The method comprises bonding a layer of resin impregnated woven grahite fibers to one surface of the honeycomb core, then curing the resin impregnates forming a stabilized honeycomb core. This stabilized core is then cut to net shape and the composite structure is formed by laying one or more resin impregnated fiber layers onto the stabilized core surfaces and curing the lay-up under heat and pressure forming the composite article. Also disclosed is a stabilized honeycomb subassembly formed by bonding a graphite fiber, resin impregnated layer onto one of the honeycomb core surfaces and curing the resins, then shaping the stabilized honeycomb core to the desired form.

Growing community of inventors

Milford, CT, United States of America

Gary J Jacaruso