Inventa-fischer Ag

Ems Inventa Ag

Raimund Schwarz

Werner Stibal

Gustav Sch&uuml;tze

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.

Process of melt-spinning polyester fibers

Polyester fibers and filaments and method for their production

The present invention pertains to a process for the production of a polyester multifilament yarn having at least 90 mol % ethylene terephthalate with a single filament titer of 1 to 20 dtex, using a central quenching system, characterized in that the method has the following steps: Extrusion of a polyethylene terephthalate polymer melt through a spinneret that has a number of capillaries between 150 and 1500, adjusting a spacer length between 5 and 150 mm, cooling of the obtained threads by means of a constant blown-air speed profile defined in the thread transit direction in that it initially rises very quickly in the region facing the spinneret, then reaches a maximum and subsequently drops off initially very quickly, then more slowly, with the average blown air speed in the vicinity of the threads being between 0.15 and 1.5 m/sec, in such a manner that the undrawn yarn produced from the process has a birefringence of between 0.050 and 0.130, and the coefficient of variation in tenacity at break between the undrawn, single filaments of a yarn amounting to a maximum of 6% with the coefficient of variation in the elongation at break amounting to a maximum of 8%, whereby finally the undrawn yarn is further processed into a finished yarn.

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Tomils, Switzerland

Raimund Schwarz