Teijin Fibers Limited

Teijin Limited

Satoshi Nagamune

Hiroyuki Osaka

Kenji Iwashita

Masahiro Konishi

[PROBLEMS] To provide a polyester monofilament which shows a high dimensional stability and excellent effects of preventing peel-off in filaments, preventing pirn barre and preventing halation and has a high fineness, a high strength and a high modulus. [MEANS FOR SOLVING PROBLEMS] A core-shell type composite polyester monofilament comprising polyethylene terephthalate at a ratio of 80% by mol or higher, which satisfies the following requirements A to F: A) the intrinsic viscosity of the core component being 0.70 or above and the intrinsic viscosity of the shell component being from 0.55 to 0.60; B) the core component amounting to 50 to 70%; C) at least the shell component containing from 0.2 to 0.4% by weight of metal microparticles; D) the fineness of the monofilament being from 5 to 15 dtex, its modulus at elongation of 5% being from 3 to 4.5 cN/dtex and its elongation at break being from 20 to 40%; E) the free shrinkage of the innermost part under specific conditions being 0.3% or less; and F) the node density is one per 100,000 m or less.

(Dope-dyed) polyester core-sheath monofilament having specific core/sheath intrinsic viscosity

There are provided a process for producing a polyester fine multifilament yarn having a single filament fineness of 0.9 dtex or below, a total number of single filaments of 100 to 400 and a birefringence of 0.03 to 0.06 comprising passing polymer streams of a polyester polymer melt extruded from a spinneret surface through an atmosphere wherein a distance of 0 to 40 mm from the spinneret surface is regulated to a temperature within the range of 100 to 300&#xb0; C., further cooling the polymer streams and then converging the cooled filaments into a filament bundle at a position of 350 to 500 mm from the spinneret surface; a process for producing a polyester fine false twist textured yarn comprising subjecting a polyester fine multifilament yarn having a single filament fineness of 0.9 dtex or below, a total number of single filaments of 100 to 400 and a bifringence of 0.03 to 0.06 to false twist texturing, the process comprising subjecting the multifilament yarn to air interlacing so as to provide a degree of interlacing of 50 to 90 interlaced spots/m measured for the false twist textured yarn, regulating the residence time in a draw-false twisting heater of 0.052 to 0.300 second and the temperature of the running filament yarn at the outlet of the heater to a higher temperature than the glass transition temperature (Tg) of the polyester polymer by 90 to 140&#xb0; C., subjecting the multifilament yarn to simultaneous draw-false twist texturing at a draw ratio of 1.40 to 1.70 times, providing the false twist textured yarn, applying a finish oil in an amount of 1.3 to 3.0% by weight based on the weight of the false twist textured yarn and winding the resulting yarn under a winding tension of 0.05 to 0.30 cN/dtex at a speed of 500 to 1200 m/min; and a process for producing the polyester fine false twist textured yarn having a single filament fineness of 0.9 dtex or below, a total number of single filaments of 100 and 400 and a birefringence of 0.03 to 0.06 comprising subjecting a polyester multifilament yarn to the simultaneous draw-false twisting and producing the false twist textured yarn, the process comprising the polyester fine multifilament yarn to air interlacing treatment before and after the simultaneous draw-false twist texturing and regulating the degree of interlacing before and after the latter air interlacing treatment to 30 to 60 interlaced spots/m and 70 to 110 interlaced spots/m, respectively.

Method for producing polyester extra fine multi-filament yarn and polyester extra fine false twist textured yarn, polyester extra fine multi-filament yarn, and polyester extra-fine false twist textured yarn

A polymer of a kind different from a polyester in an amount within the range of 0.3 to 5.0% by weight based on the polyester is added to the polyester, and the resulting composition is melt-extruded from the same pack. The extruded filament group including polyester multi-filaments is cooled once to the glass transition temperature or below, and the filament group is subsequently divided into two groups. One of the filament groups in an opened state is subjected to non-contact heat treatment at an atmospheric temperature of 120&deg; C. or above; however, the other filament group is kept in a state without being subjected to the heat treatment. The respective filament groups are then simultaneously taken off at a speed of 2500 m/min or above and subjected to doubling and mixing of the filaments.

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Ehime, Japan

Satoshi Nagamune