Polyester Filament Yarn is widely used as a material for fabrics and garments. In particular, it is a fabric characterized by a soft touch and high bulkiness. It is also suitable for making pressing applications such as insulation tapes, strapping, and a few other day-to-day uses.

A commingled multifilament yarn is made by melting-spun a core-forming molten filamentary extrudate through a spinneret having a plurality of fin-forming slit-form orifices each capable of forming a filament having a core and fins bonded to the core, and the fins being arranged around the core in the radial direction. Preferably, a spinneret has at least one core-forming orifice and 3 to 6 fin-forming slit-form orifices arranged around the core, but the number of slit-form orifices can be modified. The slit-form orifices are of different shapes and may have, for example, uniform rectangular form 6 or modified rectangular form having a round end portion.

The commingled multifilament multi-global filament (A) having the core and the fins is subjected to an alkali treatment to separate the fins from the core. The degree of separation is determined by measuring the cross-sectional area (SA) and diameter (DA) of the core, and the cross-sectional area (SB), maximum length (LB), and maximum width (WB) of the fins on a photograph before and after treatment with an alkali solution. The number of fins that are separated from the core is counted, and the degree of separation is assigned a rating of A, B, or C according to the rating value for each.

In the above procedure, it is preferable that at least 30% by weight of the core-forming molten filamentary extrudate A is melt-spun at a rate of a larger number of times than that of the filamentary extrudate B. It is also preferable that the difference in boiling water shrinkage between the two filaments is at least 5% larger than that of the core-forming molten filamentary filament A. This makes it possible to reduce the amount of the core-forming molten filamentary fiber A required for the weight-reducing alkali treatment and to increase the degree of separation of the fins from the core. The result is that the alkali-treated woven or knitted fabric has a soft touch and much-enhanced bulkiness.

Another process involves a multi-global filament A having the core and the fins being melt-spun through a spinneret having slit-form orifices of different shapes and having a corresponding degree of orientation in the radial direction to obtain a multi-global filament A. This multi-global filament yarn is then taken up and, either successively doubled or once wound and then doubled and simultaneously drawn and heat-set. Then the doubled yarn is subjected to a compressed air-blowing entangle treatment, and a commingled multifilament textile, for example, a HABUTAE fabric, is woven or knitted therefrom and subjected to alkali treatment.

The multi-global filament yarn A is then divided into a plurality of fine filaments by heating, and the fine filaments are redrawn to make a multi-global filament yarn B having the core and the fins and a thickness not larger than 8 deniers. This commingled multifilament polyester yarn is subjected to an alkali treatment to separate the fins from the core, and the alkali-treated woven or twisted fabric has a soft touch and much enhanced, high bulkiness. This is in contrast to the conventional bulky multifilament fabric that has a dense fiber structure and stiff touch and poor bulkiness.

Product description