The use of injection molding to impregnate fabric reinforcements and produce carbon or glass reinforced thermoplastic composites opens the way for high volume mass production at reasonable cost, high strength, and lightweight products. Variable mold temperature together with non-standard injection parameters allows the proper impregnation of woven carbon and glass reinforcements with standard low viscosity polymers. Testing of the injected composite parts showed a clear increase in mechanical strength. POLYM. ENG. SCI., 58:560-567, 2018. (c) 2018 Society of Plastics Engineers