Filament winding is an open molding process that is automated by using a rotating mandrel as the mold. This mandrel acts as a male mold which allows for the control surface to be on the inside, and the outside diameter size being dependent upon the laminate schedule.
The reinforcement to resin ratio can be very high with filament winding because of the automated nature of the process. Very high tensile strengths can be achieved depending upon the use of materials and their orientation.
Products that are manufactured include chemical storage tanks, pipes, stacks, pressure vessels, and rocket motors. Lightweight storage tanks have been a real area of growth as of late. The use of these high pressure vessels has been applied to air packs for firefighting as well as Liquid Natural Gas storage devices for alternative fuel vehicles.
The process works by feeding continuous strand roving through a resin bath and winding it onto a rotating mandrel. This feed mechanism traverses the length of the mandrel
to create a predetermined geometric pattern. After sufficient layers have been applied, the laminate is allowed to cure on the mandrel before the molded part is stripped away to begin another.