Production of polypropylene fine monofilaments, polypropylene fine monofilaments and use thereof

Abstract

In a process for producing fine monofilaments having improved abrasion resistance from a polypropylene having a melt flow index (MFI)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)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 61.5 cN·cm/dtex. The fine monofilaments according to the invention are useful for producing woven screen fabrics for filtration and screen printing without abrasion deposits.