MANUFACTURE OF FIBER REINFORCED PLASTIC SCREW

PURPOSE:To eliminate the collapse of crest of screw thread and contrive the stability of quality and the improvement of yield by a method wherein a plurality of yarn tapes, coated with resin, is oriented and is impregnated with thermosetting resin, thereafter, a molded rod, manufactured by introducing the yarn tapes into tubular molding mold and curing them by heating, is threaded with the screw thread. CONSTITUTION:Necessary pieces of glass yarn tape 1, whose fraying is prevented by coating resin, are passed through a comb-teeth type tape guide 3 to orient them and the group 2 of the yarn tapes are passed further through the comb-teeth type tape guide 4, thereafter, are impregnated with thermosetting resin in a resin bath 5. In this case, the glass yarn tape 1 is pressed by a pressing roller 6 to impregnate the resin and remove bubbles in the glass yarn tape forcibly in the resin bath 5. The group 2 of the resin impregnated glass yarn tapes are introduced into heating tubular molds 7, 8 to bind them and are pulled out by driving rubber rollers 10, 11 whereby the heat cured glass fiber reinforced plastic rod is obtained. The obtained glass fiber reinforced plastic rod is threaded with screw thread by machining.