System and method for producing cured composites

A system for producing a composite which comprises,

• a parent component,
• a first layer of graphite fibers impregnated with a heat bondable thermosetting resin,
• a film of heat curable adhesive positioned between said component and said first layer,
• a second layer of graphite fibers positioned on said first layer,
• and electrical connections to said second layer of graphite fibers, whereby said second layer functions as a resistance heating element so that when electrical current is passed therethrough, and the temperature raised to a predetermined value, said layers become integrally bonded through said adhesive film to said parent component.

A system for repairing a damaged structural component which comprises,

• a parent structural component to be repaired,
• a patch to be bonded to said component, said patch positioned on the surface of said parent structure, said patch including an electrical resistance heating element in the form of a layer of graphite fibers,
• a film of a heat bondable adhesive between said patch and said parent component, said adhesive film capable of bonding said patch to said parent component upon heating said adhesive film to a predetermined temperature, and
• electrical connections to said electrical resistance heating element, whereby upon heating said film to a predetermined temperature, said patch becomes integrally bonded to said parent component to form a composite.

A system for producing a composite which comprises

• a parent component,
• a first layer of graphite fibers impregnated with a heat bondable thermosetting resin,
• a film of heat curable adhesive positioned between said component and said first layer,
• a second layer of graphite fibers positioned on said first layer,
• electrical connections to said second layer of graphite fibers, whereby said second layer functions as a resistance heating element so that when electrical current is passed therethrough, and the temperature raised to a predetermined value, said layers become integrally bonded through said adhesive film to said parent components, and
• a bagging material positioned over said resistance heating element, for applying pressure to the assembly for bonding said heating element to said component during resistance heating to said predetermined temperature value.

A system for repairing a damaged structural component which comprises,

• a parent structural component to be repaired,
• a patch to be bonded to said component, said patch positioned on the surface of said parent structure, said patch including an electrical resistance heating element in the form of a layer of graphite fibers,
• a film of a heat bondable adhesive between said patch and said parent component, said adhesive film capable of bonding said patch to said parent component upon heating said adhesive film to a predetermined temperature,
• electrical connections to said electrical resistance heating element, whereby upon heating said film to a predetermined temperature, said patch becomes integrally bonded to said parent component to form a composite,
• plate means positioned over the assembly, and
• vacuum bagging over said plate means for applying pressure to said assembly for bonding said patch to said parent component during resistance heating to said predetermined temperature.

A process for producing a composite, which comprises,

• placing a parent component of said composite in contiguous relation with an electrical resistance heating element comprising a layer of graphite fibers,
• placing a film of heat bondable material between said resistance heating element and said component,
• placing an additional layer of graphite fibers impregnated with a heat bondable thermosetting resin or a high temperature thermoplastic resin, between said electrical resistance heating element and said heat bondable film, and
• passing an electric current through said resistance element and heating said bondable film to a predetermined temperature, whereby said resistance heating element and said additional layer become bonded to said component upon passage of electrical current through said heating element.

A process for producing a composite, which comprises,

• placing a parent component of said composite in contiguous relation with an electrical resistance heating element comprising a layer of graphite fibers,
• placing a film of heat bondable material between said resistance heating element and said component,
• vacuum bagging the assembly,
• passing an electric current through said resistance element and heating said bondable film to a predetermined temperature, thereby causing said heating element to become bonded to said component, and
• applying pressure to the assembly during passage of electric current through said heating element and during said bonding.

A process for repairing a damaged structural component which comprises,

• placing a patch on the surface of said structural component, said patch including an electric resistance heating element in the form of a layer of graphite fibers,
• incorporating an adhesive film of a heat curable thermosetting resin between said patch and said structural component,
• vacuum bagging the assembly of said structural component and said patch,
• passing an electric current through said resistance heating element and heating said heat curable thermosetting resin to a predetermined temperature, thereby causing said patch and said heating element to be integrally bonded to said structural component to form a composite, and
• applying pressure to said assembly during passage of an electric current through said resistance heating element.