Abstract: A glass fiber mat for a stampable sheet includes long fibers and short fibers which will not separate even during forming and which are distributed uniformly to make the features of the respective fibers effective. A production system includes a double belt press type laminator which stacks the glass fiber mat, a thermoplastic resin melt and a film which is taken up and applies heat and pressure for impregnation, and cools while maintaining a pressure condition. A supply supplies the glass fiber mat into the laminator. A pair of pressure shearing rollers are arranged between the supply and an endless belt of the laminator for partially cutting the glass fibers into short fibers. The rollers are made of steel to apply line pressure to the glass fiber mat to shear the continuous fibers to uniformly distribute the short fibers in long fibers.

Abstract: A fiber reinforced polyamide resin composite material is suitable for use as a molding material. A liquid lactam added with an anionic polymerization catalyst and another liquid lactam added with an activator are supplied to an impregnation chamber while being mixed together at a predetermined or selected ratio. In the impregnation chamber, long reinforcing fibers are impregnated with the mixed liquid to form a strand. Then a coating layer of thermoplastic resin is continuously formed all over the outer peripheral surface of the strand, after which the strand is introduced into a heated polymerization chamber for anionic polymerization of the mixed liquid in the reinforcing fibers. The strand is cut into pellets of a predetermined or selected length after or without removing the coating layer. The composite material manufactured by this method has a high adhesive strength between the reinforcing fibers and the resin and provides excellent physical properties to ultimate moldings.