Abstract: In a process for producing fine monofilaments having improved abrasion resistance from a polypropylene having a melt flow index (MFI)230° C./2.16 kg of 2–16 g/10 min at a linear density of 5–20 dtex (0.027 mm–0.053 mm), a compound consisting of 80 to 99.9% by weight of chips and 20 to 0.1% by weight of an additive is added to the extruder, the melt is spun at a speed of at least 1200 m/min, the fibre is cooled in an air bath at room temperature, supplementarily stretched at a temperature of 110–150° C. to a linear density of 5–20 dtex and wound up. The monofilaments comprising a polypropylene having a melt flow index (MFI)230° C./2.16 kg of 2–16 g/10 min, having improved abrasion resistance, and a linear density of 5–20 dtex (0.027 mm–0.053 mm) and an abrasion resistance score ?2. The monofilaments have a tenacity of at least 48 cN/tex and an elongation at break of less than 45% for a mechanical constant (constante méchanique) of at least 295 cN/tex and a specific work to break value of more than 61.

Abstract: In a process for producing fine monofilaments having improved abrasion resistance from a polypropylene having a melt flow index (MFI)230° C./2.16 kg of 2-16 g/10 min at a linear density of 5-20 dtex (0.027 mm-0.053 mm), a compound consisting of 80 to 99.9% by weight of chips and 20 to 0.1% by weight of an additive is added to the extruder, the melt is spun at a speed of at least 1200 m/min, the fiber is cooled in an air bath at room temperature, supplementarily stretched at a temperature of 110-150° C. to a linear density of 5-20 dtex and wound up. The monofilaments comprising a polypropylene having a melt flow index (MFI) 230° C./2.16 kg of 2-16 g/10 min, having improved abrasion resistance, and a linear density of 5-20 dtex (0.027 mm-0.053 mm) and an abrasion resistance score ≦2.

Abstract: A method for the production of melt-spun fibers comprising polyethylene terephthalate as a fiber-forming polymer, through polycondensation or melting of the fiber-forming polymer forming a melt and subsequently melt spinning, comprises mixing 0.1-4 wt %, relative to the fiber-forming polymer, of polymethyl methacrylate with the fiber-forming polymer before the melt spinning and dispersing the polymethyl methacrylate in the fiber-forming polymer to form unoriented melt fibers. During the melt spinning, the spinning speed of the fibers is set at up to 8000 m/min, whereby through the inclusion in the unoriented melt fibers, extruded from a sincerest, rod-shaped inclusions of the polymethyl methacrylate with a lateral particle size of less than 800 nm are obtained.

Abstract: The invention relates to fibers or filaments, consisting predominantly of polyethylene terephthalate as a fiber-forming polymer, that contain 0.1-4 wt %, relative to the fiber-forming polymer, of polymethyl methacrylate as another polymer, predominantly in the form of rod-shaped inclusions, whereby in the unoriented melt fibers under the spinneret, the mean lateral diameter of the rods is less than 800 nm and the polymethyl methacrylate has, a weight average molecular weight of between 20,000 and 200,000 g/mol, and whereby the spinning speed of the spun fibers in the production is up to 8000 m/min. Furthermore, the invention relates to a method for the production of these novel polyester fibers and filaments.

Abstract: The invention relates to postcondensed paper machine felts comprising a polyamide base fabric and a polyamide coating needled thereon, the paper machine felts having a relative solution viscosity in sulfuric acid in accordance with the DIN 53,727 standard of 5 or more.The invention further relates to a method of increasing the molecular weight of paper machine felts which comprises impregnating the paper machine felts with a solution of postcondensation catalysts, followed by drying and thermally postcondensing the felts below the melting point of the polyamide in a solid phase by the exclusion of oxygen.