maintain the resin in a molten state the pumping is controlled at a rate which will replace the resin as it is consumed while maintaining the rolling resin bank at the minimum effective level the thickness of the coating is controlled by the die gap or aperture 28 between the roller 26 and the doctor blade 29 and is adjustable by means of adjusting screws not shown either manually or automatically in response to quality control measurements flow of the resin into and through the narrowing die aperture 28 produces a substantial increase in hydrostatic pressure by processes analogous to those described in u s pat no 3 765 817 for calendering operations the hydrostatic pressure which varies with the resin viscosity and flow rate or coating speed causes some penetration of resin between the individual fibers at the strand surface and ensures good adhesion of the resin coating as it exits the coating roll the strand exiting the coating rolls may be described as a coated band or tape impregnating the fibers requires that the resin be forced uniformly into the strand thus penetrating between the individual fibers in order to accomplish impregnation of the fibers the strand 2 then passes through kneader rolls 23 to further work the strand the kneader rolls 23 are disposed along the line of strand travel in a manner to impart considerable working to the strand as shown six rolls are employed located to provide wrap angles greater than 30 u00b0 and preferably as great as 180 u00b0 or even greater the kneader rolls will be.