Strands powdered by electrostatic method

A method for manufacturing a tape from reinforcement filaments impregnated with a thermoplastic polymer matrix, a tape which has a constant width over the whole of its length, wherein the filaments extend along a direction parallel to the length of the tape, from a strand of filaments stemming from a supply coil, the method comprising, from a coil for supplying strand up to a coil for storing the impregnated and consolidated tape:

• a) managing the tension between the supply coil and the storage coil,
• b) guiding the strand so as to obtain a strand moving in translation over a line coinciding with a longitudinal axis, a so called machine axis, extending as far as the proximity of the storage coil,
• c) transverse spreading of the strand to a predetermined width greater than the rated width of the tape,
• d) managing the width of the strand to a predetermined value comprised between the maximum spreading out width and the rated width of the final tape,
• e) pulling the strand and maintaining the strand width,
• f) grounding the strand,
• g) deposition of the polymer as a powder on the strand, by electrostatic powder coating, with a mass polymer level of greater than 25% and up to about 75%, obtaining an impregnated tape,
• h) melting or softening the polymer,
• i) calendering and calibration in width and in thickness of the tape,
• j) optionally measuring the width of the tape, and
• k) winding the tape on the storage coil.