Abstract: The invention relates to a process for simultaneous spin-drawing of one or more heavy-duty yarns, comprising the following steps:

Abstract: Polyester staple fibers with high resistance to pilling contain (1) a polyester component consisting of at least 90 mol % polyethylene terephthalate, after its polycondensation, and (2) 1 to 7% by weight, relative to the polyester component, of a polyalkylene glycol block polymer with the formula ##STR1## in which the polyoxypropylene core has a mean molecular weight of 3000 to 4000 and a, b and c are integers such that the polyoxyethylene groups form 20 to 60% by weight of the block polymer, which has a mean molecular weight of 3750 to 10000. The staple fibers are prepared by admixing the polyester component and the block copolymer evenly in a separate phase and spinning the two together in the usual manner. The polyester component preferably is polyethylene terephthalate homopolyester, to which 2-4% by weight of the block copolymer is admixed.

Abstract: An apparatus for melt spinning multifilament yarns from fiber-forming polymers at wind-up speeds of at least 2,000 m/min, includes a spinnerette, a porous tube for solidifying the filaments, a convergence element for the filaments and a wind-up device. The apparatus further includes, at least between the spinnerette and the convergence element, an essentially vertical spinline. The porous tube is open in the spinning direction and concentric relative to the spinline.

Abstract: An apparatus and use thereof for melt spinning multifilament yarns from fiber-forming polymers at windup speeds of at least 2000 m/min is disclosed. The apparatus has a spinnerette, a cooling element for solidifying the filaments, a convergence element for the filaments and a wind-up element and having, at least between the spinnerette and the convergence element, an essentially vertical spinline. The cooling element is a porous tube which is open in the spinning direction and concentric relative to the spinline. The porous tube has disposed downstream of it a further, non-porous tube. It is particularly advantageous for the porous tube to have a length from 10 to 800 mm. It is particularly advantageous for the further, non-porous tube disposed downstream of the porous tube to have a length from 200 to 800 mm.

Abstract: A fiber predominantly composed of polyethylene terephthalate as fiber polymer, which contains 0.1 to 5% by weight, based on the fiber polymer, of a polyalkyl methacrylate, imidated up to 50 to 90%, predominantly in the form of inclusions. Also provided is a process for the production of melt-spun fibers, essentially composed of polyethylene terephthalate, by melting the fiber polymer and subsequent melt spinning, characterized in that the fiber polymer receives an admixture of 0.1 to 5% by weight, based on the fiber polymer, of a polymer only partially soluble in this and essentially composed of imidated polyalkyl methacrylates which are imidated up to 50 to 90% by reaction of polyalkyl methacrylates, the ester group of which contains an alcohol having 1 to 6 C atoms, with a primary amine having 1 to 3 C atoms, and the acid and/or anhydride content of which is less than 0.25 milliequivalents per gram and, possibly, other additives prior to the melt spinning.

Abstract: Melt-spun polyether imide fibers are disclosed wherein the granules are brought to a moisture content of below 0.05%, the melt is extruded from nozzles at a temperature between 300.degree. and 440.degree. C., and the spun fibers are taken up at a speed of up to 2,500 m/min. Fibers produced in this fashion can be stretched up to 1:3 and spin-dyed.

Abstract: Production of drawn dilaments by cooling freshly spun filaments at a temperature below the setting point and taking them off at 3500 m/min while passing them over heated surfaces, such heated surfaces being 20 to 300 mm long heated to from 450.degree. to 650.degree. C. and arranged at a distance of from 1500 to 6500 mm from the spinneret.