Method and apparatus for spinning a synthetic multi-filament yarn
AssigneeBarmag AG
InventorsHeinz Schippers, Rahim Gross
Life of this patent
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Abstract
A method and apparatus for spinning, drawing and winding a synthetic multi-filament yarn, wherein the yarn is subjected after drawing and prior to winding to a heat treatment for purposes of reducing its shrinkage tendency. In the heat treatment, the yarn advances along an elongated heating surface closely adjacent thereto but substantially in no contact therewith. The heating surface has a surface temperature which is above the melt point of the yarn. During the heat treatment, the yarn is subjected to a tension which is lower than the tension required for plastic deformation. The yarn wound by this method has a heat shrinkage tendency which is typically more than about 20%.
Claims36
A method of spinning a synthetic multi-filament yarn comprising the steps of
- extruding a polymeric melt to form a plurality of advancing multi-filament filaments, and gathering the filaments to form an advancing yarn,
- drawing the advancing yarn, and thereafter
- heating the advancing yarn by guiding the advancing yarn along a path of travel which is adjacent but at least substantially spaced from an elongate heating surface, with the heating surface being heated to a temperature which is above the melting temperature of the yarn, and while subjecting the advancing yarn to a tension which is insufficient to cause a plastic deformation of the yarn, and then
- winding the advancing yarn into a package.
An apparatus for spinning a synthetic multi-filament yarn comprising
- means for extruding a polymeric melt to form a plurality of advancing filaments, and gathering the filaments to form an advancing multi-filament yarn,
- means for drawing the advancing yarn and so as to define a drawing zone,
- means defining a draw-free zone downstream of said drawing zone and wherein the advancing yard is subjected to a tension insufficient for drawing of the yarn,
- a heater positioned within the draw-free zone and comprising an elongate heating surface, and means for heating the heating surface to a temperature which is above the melting temperature of the yarn, and
- a winder positioned downstream of said heater for winding the advancing yarn into a package.
An apparatus for spinning a synthetic multi-filament yarn comprising
- means for extruding a hot polymeric melt to form a plurality of advancing filaments, and gathering and cooling the filaments to form an advancing multi-filament yarn,
- a heater positioned along the path of the advancing yarn and comprising an elongate heating surface, guide means for guiding the advancing yarn through the heater so as to be at least substantially spaced from the heating surface, and means for heating the heating surface to a temperature above the melting temperature of the yarn, and
- winding means for advancing the yarn from the extruding means and through said heater at a speed of at least 5,000 meters per minute and for winding the advancing yarn into a package, and such that the winding means acts to draw the advancing filaments and yarn until the yarn has cooled to an extent that drawing ceases, and wherein the heater is positioned downstream of the point at which the drawing ceases.
Dependencies are inferred from the claim text.