초록

A method of forming a closed cell thermoplastic foam duct and a method of forming a duct and attaching it to an aircraft environmental control system. The environmental control system includes a duct made of closed cell thermoplastic foam, such as polyvinylidene fluoride foam.

대표청구항 ▼

1. A method of forming a duct, the method comprising the steps of: skiving a thermoplastic bun having a closed cell structure to form a sheet, the bun comprising an expanded foam polyvinylidene fluoride (PVDF) material;cutting the sheet to create a first edge and a second edge of the sheet;forming a

1. A method of forming a duct, the method comprising the steps of: skiving a thermoplastic bun having a closed cell structure to form a sheet, the bun comprising an expanded foam polyvinylidene fluoride (PVDF) material;cutting the sheet to create a first edge and a second edge of the sheet;forming a crenulation pattern in the first edge of the sheet so as to form a first crenulated edge;forming a crenulation pattern in the second edge of the sheet so as to form a second crenulated edge;cutting the first crenulated edge so as to create a bevel along the first crenulated edge;cutting the second crenulated edge so as to create a bevel along the second crenulated edge, the first crenulated edge reciprocally matching the second crenulated edge;wrapping the sheet around a mandrel;applying pressure and heat to thermally weld the first edge and the second crenulated edge together so as to form the duct; andwelding a wire around the duct, the wire comprising a thermoplastic material, the wire wrapped around the duct in a helix pattern, wherein the pitch of the helix is selected to dampen a noise of a given frequency range;wherein the step of applying pressure and heat comprises pressing an outside tool against an overlapping seam of the first edge and the second edge. 2. The method of claim 1, wherein an angle of the helix is selected to dampen a noise of a given frequency range. 3. A method of forming a duct and attaching it to an environmental control system of an aircraft the method comprising the step of: skiving a sheet from a bun that is expanded into a foam from a polyvinylidene fluoride (PVDF) material;cutting the sheet to create a first edge and a second edge;crenulating a first edge of the sheet so as to form a first crenulated edge;crenulating the second edge of the sheet so as to form a second crenulated edge;cutting the first crenulated edge so as to create a bevel along the first crenulated edge;cutting the second crenulated edge so as to create a bevel along the second crenulated edge, the first crenulated edge reciprocally matching the second crenulated edge;thermally welding the first crenulated edge to the second crenulated edge to form the duct;attaching the duct to the environmental control system of the aircraft; wherein the duct is a first duct and wherein the environmental control system further comprises a second duct; andcoupling the first duct to the second duct using a foam sleeve comprising a polyvinylidene fluoride foam. 4. The method of claim 3, wherein the first duct and the foam sleeve are coupled using a clamp comprising a first section in the shape of a ring and a second section comprising a partial frustro-conical shape attached to the first section. 5. The method of claim 3, wherein the first duct, the second duct, and the foam sleeve are coupled using an adhesive. 6. A method of forming a duct, the method comprising the steps of: skiving a thermoplastic bun having a closed cell structure to form a sheer, the bun comprising an expanded foam polyvinylidene fluoride (PVDF) material;cutting the sheet to create a first edge and a second edge of the sheet;forming a crenulation pattern in the first edge of the sheet so as to form a first crenulated edge;forming a crenulation pattern in the second edge of the sheet so at to form a second crenulated edge;cutting the first edge so as to create a bevel along the first crenulated edge;cutting the second crenulated edge so as to create a bevel along the second crenulated edge, the first crenulated edge reciprocally matching the second crenulated edge;wrapping the sheet around a mandrel;applying pressure and heat to thermally weld the first crenulated edge and the second crenulated edge together so as to form the duct;molding the duct in a mold; andpost forming the duct with injected gas and heat;wherein the step of applying pressure and heat comprises pressing an outside tool against an overlapping seam of the first edge and the second edge.