Patent ID: 7582177

Claim:
A process for the production of fiber-reinforced plastic tubing having plural fiber-reinforced plastic intermediate material layers, comprising the steps of: laminating two or more fiber-reinforced plastic intermediate material layers, wherein: angles of directions of orientation of adjacent layers are the same order but are reversed where the fibers of one layer have an angle of +15° to +75° and the fibers of the adjacent layer has an angle of −15° to −75° with respect to a cored bar, respectively, a resin content is provided in the two or more fiber-reinforced plastic intermediate material layers having angles of directions of orientation that are a combination selected from the angle of +15° to +75° and the angle of −15° to −75°, the resin content being 15 to 33 mass %, and the laminating step further includes the step of: passing the two or more fiber-reinforced plastic intermediate material layers through a belt-type heat press at a roller pressure of 1 kg/cm 2 and a temperature of 30° C.; putting the laminated fiber-reinforced plastic intermediate material in a bag-like membrane material; sealing the membrane material off; depressurizing an inside of the bag-like membrane material to a pressure of 60 to 160 mmHg to remove air cells present at the laminated interface; wherein the depressurizing step is carried out after the laminating step; removing the intermediate material from the bag-like membrane material; and winding the material on the cored bar to form fiber-reinforced plastic intermediate material layers prior to curing.