Manufacture of unidirectional fiber reinforced thermoplastics

Abstract

The method for the manufacture of unidirectionally fiber reinforced thermoplastic bands comprises a pressure impregnation of a fiber strand in a bath with a dispersion of thermoplastic particles. Heat treatments for the drying of the strand and a melting on of the particles taken up by the strand follow the pressure impregnation. The strand is drawn through the bath at a predetermined draw-off speed about a plurality of deflection elements. The dispersion of the bath is largely held in a stationary state, namely through the supply of an infeed dispersion with a first particle concentration and through an initial setting of a second particle concentration in the bath: The infeed dispersion is fed in continuously or periodically, with the first particle concentration being held constant. A corresponding feeding in of a dispersion of higher particle concentrations as well as an additional amount of dispersing medium is possible. The second particle concentration is set to a value which remains constant through an automatic self-setting alone. In this the two named concentrations depend in an empirically determinable manner on a thermoplastic content of the band to be achieved and on the draw-off speed.