CS234055B1 - Method of polycapromide carpet tows pressed to shape making - Google Patents

Abstract

Process of polycapamide production Shaped Carpet Cables in which the unbonded fiber is spun from the melt at towing speeds from 150 to 300 m / min, resulting in fineness undifferentiated fiber from 7000 to 13000 dtex is achieved by using a spinneret, or a number of nozzle sets from 130 to 220 and obtained fibers under the nozzle they are air cooled so that they are not indented fibers have a homogeneous structure with content 25 to 30% by weight of the ordered fraction macromolecular blades, determined by measuring the molecular weight.

Description

The invention relates to a process for the production of polycaproamide cables with improved properties and improved processability in a draw-molding process without the need to bundle multifilaments into a cable of the desired elementary and overall fineness.

Previously, the production of molded polycaproamide carpet cables is carried out by melt spinning at a draw-off speed of 550-600 m / min. using spinnerets with 70 apertures to obtain an undrawn fiber having a total fineness of 3100-3300 dtex.

To obtain a molded cable with a final overall fineness of 2600, resp. 4000 dtex must be a pooling of two resp. 3 of the fiber thus prepared. The bundling is performed in a drawing-forming operation with very poor processability of 35-40 breaks per 1 ton of elongated fiber.

The above drawbacks are overcome by a process for producing polycaproamide molded carpet cables with improved properties, in particular processability in the post-forming process of the present invention, wherein the undrawn fiber is prepared by melt spinning at extremely low draw speeds of 170-300 m / min. 7000 to 13000 dtex is achieved by using a spinneret or nozzle assembly with a total number of 130 to 220 holes.

The fiber obtained under the spinneret was air-cooled so that the undrawn fibers had a homogeneous structure containing 25-30% by weight of the ordered proportion of macromolecular chains determined by density measurement.

The fiber thus prepared is characterized by higher structural uniformity, higher ductility by up to 15%, up to 8 times better

234 053 processability in the drawing-forming process expressed in number of breaks per tonne of fiber and up to 50% lower incidence of broken fiber capillaries *

The preparation of such fiber is ensured without disturbing the spinning capacities with the creation of conditions for the possibility of increasing the spinning capacities. At the same time, the bundling of 2 to 3 fiber stitches in the draw-molding process is eliminated with 3 to 5 times waste conservation.

Example 1.

In the manufacture of the polycaproamide molded cable of a gauge fineness of 2600 dtex, the melt spinning is performed at a take-off speed of 280 m / min using a spinneret with 140 holes. After the polymer flows out of the spinneret, the fiber is cooled by a stream of conditioned air at a temperature of 16 + 1 ° C, a relative humidity of 65 + 2% at an air speed

1.4 - 1.5 m / sec. After cooling, the filament is applied to the fiber with a content of 0.7 ± 0.2% and the filament is wound at the specified speed of 280 m / min. An undrawn fiber of fineness of 7200 dtex is obtained with a content of 25-30% of the ordered proportion of macromolecular chains determined by the specific gravity method. The relative viscosity of the non-crosslinked fiber is 2.85 ± 0.05. The undrawn filament is processed on a drawing machine at a drawing ratio of 3.2. A formed polycaproamide fiber with a final overall fineness of 2600 dtex and 140 capillaries with a 15% shrinkage and a 50 + ductility of 5 is formed.

Example 2.

In the production of a polycaproamide molded cable of a calco final fineness of 4000 dtex, the melt spinning is carried out at a take-off speed of 185 m / min. using a 210-hole spinneret. After the polymer discharge from the spinneret, the fiber is cooled by a stream of conditioned air at a temperature of 16 + 1 ° C, a relative humidity of 65 + 2% at an air speed

1.4 - 1.5 m / sec. After cooling, the filament is applied to the fiber with a content of 0.7 ± 0.2% and the filament is wound at the specified speed of 280 m / min. An undrawn fiber of fineness of 11000 dtex is obtained with a content of 25-30% of the ordered proportion of macromolecular chains determined by the specific gravity method. The relative viscosity of the non-crosslinked fiber is 2.85 ± 0.05.

234 055

The undrawn fiber is further processed on a drawing-forming machine at a ratio of 1: 3.2. A shaped polycaproamide fiber with a final total fineness of 4000 dtex is formed, 210 capillaries with a 15% shrinkage and a 50 + 5 elongation. 5 breaks per tonne of elongated fiber.

Claims (1)

OBJECT OF THE INVENTION 234 055 A method for producing polycaproamide molded carpet cables, characterized in that the undrawn fiber is melt spun at a take-off speed of from 150 to 300 m / min, the resulting fineness of the undrawn fiber being from 7000 to 13000 dtex being achieved using a spinneret or nozzle assembly with and the obtained fibers below the die are air cooled so that the undrawn fibers have a homogeneous structure containing 25-30% by weight of the ordered proportion of macromolecular chains, determined by measuring the specific gravity.