General Dynamics Corporation

General Dynamics (Space Systems Division)

Ivan K Hall

John Gagliani

Michael J Yokota

Ronald K Giesy

Douglas S Cox

Edward M Gilchrist

A method of manufacturing a fiber reinforced, resin matrix, tank with an integral fitting, such as an internally threaded pipe connection, bulkhead door or manhole entryway. A thread form tool having a cylindrical bore and a rounded pattern thread forming outer surface at one end is provided. The tool is secured to a drive shaft extending through the tank forming mandrel with the thread forming end adjacent to the mandrel. A second, thread is formed on the opposite end of the threat form tool opposite the tank mandrel and carries a consolidation nut. A consolidation washer rides on a wider cylinder surface of the thread form tool intermediate the two threaded ends. At least one fabric doily or band is placed over the thread forming tool rounded threads and the tank mandrel is filament wound with high strength fibers impregnated with a resin in a conventional manner, with filaments overlapping the rounded thread area. When sufficient filaments have been wound, the consolidation nut is tightened, driving the spacer and consolidation washer towards the filaments on the rounded thread region, consolidating the windings and forming a flat seating area substantially perpendicular to the mandrel axis. The resin is then cured and the thread forming tool assembly is removed.

Method for manufacturing an integral threaded connection for a composite

A method for continuous processing/in-situ consolidation and curing of thermoset resin impregnated fiber tow into a composite product having minimal porosity and being relatively void free. The method provides for preconditioning a fiber, impregnating a continuous fiber tow with a low viscosity thermoset resin to complete saturation and then simultaneously outgassing and advancing the resin impregnated tow. The preconditioned tow is then applied to a substrate such as a heated rotating mandrel in a filament winding procedure where heat is applied to the nip of the touch-down of the tow to the mandrel with the simultaneous application of pressure for initial consolidation of the tow upon the substrate. Additional pressure and heat are applied to the tow as the mandrel is rotated to provide for advancing the stage of the resin and further consolidation of the material. The combination of the pressures and heat applied to the outer surface of the material on the mandrel produce a unitary composite product without delaminations. Preferably, the serial continuous process is monitored using an appropriate inspection method focused on the material on the mandrel to permit in-line optimization of the product as it is being consolidated and cured on the mandrel. The method is equally applicable to various automated resin matrix composite material deposition arrangements such as filament winding, tape laying, and pultrusion.

Continuous processing/in-situ curing of incrementally applied resin

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San Diego, CA, United States of America

Ivan K Hall