The resin and the isotropically distributed reinforcements flow to fill the mold cavity. Mold closure times vary from 30 seconds up to several minutes depending on part design and material formulation. When the mold opens, parts are ready for finishing operations such as deflashing, painting, bonding, and installation of inserts for fasteners. By varying the formulation of the thermoset material and the reinforcements, parts can be molded to meet applications ranging from automotive class A exterior body panels to structural members such as automobile bumper beams. The filament winding process is used in the fabrication of tubular composite parts.
Typical examples are composite pipe, electrical conduit, and composite tanks.
Fiberglass roving strands are impregnated with a liquid thermosetting resin and wrapped onto a rotating mandrel in a specific pattern. When the winding operation is completed, the resin is cured or polymerized and the composite part is removed from the mandrel . Capital investment is relatively higher compared to open mold processes. The primary expense for an existing filament winder would be the cost of the winding mandrel for a specific application. Market Development Alliance of the FRP Composites Industry.