A method of forming a tube with an inner wall having a high-wear resistance and a low coefficient of friction comprising: deaerating an uncured thermosetting resin, coating glass filaments with the resin, and winding the glass filaments about a rotating mandrel in a band at a pitch no greater than the bandwidth. A first layer of wound glass filaments is formed in a single axial pass along the mandrel, and this first layer is helically overwound with subsequent layers. The resin coating the wound glass filaments is thereafter cured and the resulting tube is removed from the mandrel.
In the embodiment described in the specification, a high temperature wet filament winding arrangement has a wet bath containing a resin at a temperature above 500.degree. F. and filaments drawn from a spool rack are passed through the wet bath and then through a heated comb which maintains the temperature of the filaments above 500.degree. F., after which the filaments are passed through a heated passage controlled to maintain the temperature above 500.degree. F. A winding eye, also heated to maintain the filament temperature above 500.degree. F., directs the heated fibers onto a mandrel where they are wound in uniform layers into the form of a final product. A mandrel heater heats the mandrel to which the fibers are being applied so as to maintain a uniform temperature above 500.degree. F.
A method for fabricating a composite pressure vessel comprising layering up of an uncured carbon fiber fabric/resin prepreg on a mold. Thereupon an uncured insulating rubber is layered up and combined with the uncured carbon fiber fabric/resin prepreg by autoclaving. This method produces an insulator for a composite pressure vessel which insulator is an aspect of the present invention.
