Abstract: A method of producing continuous multifilament yarns of polyethylene terephthalate comprising the steps of extruding the polymer in the molten state, cooling the filaments by blowing, and application of dressing, interlacing and winding. The polymer viscosity is in the range of 0.52 to 0.82. The filaments, on exiting the die, meet a conduit which protects them against air streams. Winding is carried out at rates in the range of 3,500 to 5,500 meters/minute. The fiber yielded by the method has a modulus in the 300 to 500 cN/tex range, tenacity in the range of 30 to 40 cN/tex, ultimate elongation varying from 50% to 80%, and shrinkage in water of between 3% and 8%.

Abstract: A method of high-speed spinning polyamidic fiber, comprising the steps of extruding the polymer in the molten state, cooling the filaments by blowing, and finishing, which is performed in two stages, one upstream and the other downstream of the interlacing device.The latter device includes a containing enclosure wherein the interlacing nozzle and at least two pairs of yarn thread guides are accommodated.Fibers obtained with the method have 5 to 29 knots per meter.