JPH02127514A - Production of differently shrinkable polyester combined filament yarn - Google Patents

Abstract

PURPOSE:To obtain the title combined filament yarn having uniform and stable physical properties and flexible feeling in high efficiency and readily, by drawing only one of two yarns spun at different speeds and then combining and interlacing the yarns. CONSTITUTION:Polyethylene terephthalate is spun from two spinnerets 1A and 1B, respectively, yarn A is taken-off by an unheated cold roller 4 at 4,000-6,000m/minute speed and yarn B is taken-off at 1,000-4,000m/minute by a hot roller 5 having surface temperature preferably heated to a temperature from a glass transition temperature -20 deg.C to a glass transition temperature +30 deg.C. Then both the yarns are put in order, doubled by a second roller 7 rotating at the same speed as that of the cold roller 4 and having preferably 70-100 deg.C surface temperature, the yarn B is drawn preferably 1.5-4 times, combined and interlaced by an interlacing nozzle 9 and wound around a bobbin 10 to give the aimed combined filament yarn.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for obtaining differentially shrinkable mixed yarn using a direct spinning/drawing method in which drawing is performed immediately after spinning.

(Prior art) In recent years, in order to obtain polyester fibers, a direct spinning/drawing method has been developed in which melt-spun undrawn yarn is directly supplied to a drawing process without being wound up on a bobbin or the like, thereby achieving low-cost production. Proposed. On the other hand, in order to improve the flat feel of synthetic m-maintained fabrics and obtain a bulky feel, it is widely practiced to use a mixed shrinkage yarn made of yarns with different water production shrinkage rates.

JP-A-60-126816 and JP-A-59-180809 disclose the production of such differentially shrinkable mixed fiber yarn using the above-mentioned direct spinning/drawing method.

(Problems to be Solved by the Invention) However, the invention of JP-A-60-126816 applies a drawing condition difference to yarns spun at a high speed of 510 Q m/min or higher to obtain a shrinkage rate difference. The physical properties of the yarn become unstable and tend to cause defects such as streaks.

Moreover, the invention of JP-A-59-180809 discloses that the spinning speed (
Winding speed) is 8600 to 4800rn/m 1 n
Since the spinning rate is low, productivity is poor, and since it is not possible to obtain a large difference in shrinkage rate within such a spinning speed range, the process becomes complicated because the shrinkage rate changes depending on the difference in heat treatment.

The present invention is intended to solve these problems, and aims to easily produce a differential shrinkage mixed fiber yarn with stable physical properties using a highly efficient direct spinning/drawing method.

(Means for Solving the Problems) The present invention involves forming polyethylene terephthalate into yarn groups of at least two spinnerets each before spinning, drawing at least one yarn group, and drawing the remaining yarn groups. When obtaining a mixed fiber yarn by doubling without drawing, the yarn spun from one spindle is spun at a spinning speed of 4000 to 6000 m/mi.
The yarn B spun from the other nozzle was taken up by an unheated cold roller so that the spinning speed was 1000 to 4.
000rn/m 1 n, then both yarns A-B are fed to a second roller rotating at substantially the same speed as the cold roller, and then subjected to a mixed fiber entangling treatment. This is a characteristic feature.

The polyethylene terephthalate used in the present invention includes:
It may be a modified polyethylene terephthalate that has ethylene terephthalate as its main repeating unit and copolymerized with about 15 mol % or less of other components. or,
Polyethylene terephthalate has an intrinsic viscosity (dissolved in orthochlorophenol and measured at 26°C) of 0.
A value of about 68 is appropriate.

In the present invention, such polyester is melt-spun from two different spindles, and each spinneret is oiled and drawn separately. In this case, the spinning speed, which is the running speed of the yarn on the surface of the cold roller and hot roller that performs take-up, is 4000 to 600 Qm/min for one yarn A.
%The other yarn B is to o O~4000m/min
The collection will be done so that Yarnman's spinning speed is 40
If the speed is less than 00 m/min, not only will the productivity decrease, but the yarn orientation will not be sufficiently improved, and the texture of the woven or knitted fabric will become hard due to width adjustment or heat treatment during dyeing in the subsequent process, which is unsuitable. If the spinning speed of yarn B is outside the range, the drawing ratio cannot be obtained, which is inappropriate.

Furthermore, the roller that takes yarn A is a cold roller whose surface temperature is room temperature and does not undergo active heat treatment, and the roller that takes yarn B is a cold roller whose surface temperature is between -20 and +80 above the glass transition temperature of the yarn. Use a hot roller that has been immersed in a heated area.

Next, the taken yarns A-B are aligned and sent to a second roller. The temperature of the surface of the second roller is preferably 100° C. or lower; if the surface temperature of the second roller is 100° C. or higher, the ring water shrinkage of the yarn B will be significantly reduced, which is inappropriate. Further, the surface temperature of the second roller may be set to room temperature, but it is preferably set to 7 to avoid winding of the package.
It is preferable to set the temperature to 0°C or higher. Further, the second roller is rotated at a one-frame speed with the cold roller. Therefore, no stretching action is performed between the cold roller and the second roller, but stretching is performed between the hot roller and the second roller, and the stretching ratio is preferably about 1.5 to 4 times, so the yarn A -B
It is also preferable that the ratio of the spinning speeds between the two is about 1.6 to 4.

The yarn material B that has passed through the second roller is then subjected to a mixed fiber entanglement treatment to provide about 15 to 20 interlaced portions/m using a fluid such as air to form a mixed fiber yarn.

The present invention will be explained in more detail below with reference to the drawings. 1st
The figure is a schematic diagram illustrating the steps of the method of the present invention, and shows the process of the method of the present invention.
A) (IB) Among the spun yarns, yarn A, which is taken off at a high speed, is applied with an oiling nozzle (2), and yarn B, which is taken off at a low speed, is separately applied with an oil agent by an oiling roller (3). Ru. Next, the yarn A passes through the mirror-finished half-circumferential surface of the cold roller (4), and the yarn B passes through the hot roller (5), the upper 20th roller (7), and the second roller.
The fibers are heat-set by encircling the separate rolls (8) one or more times, and are mixed and entangled by the interlace nozzle (9) and wound around the bobbin αG.

(Function) In the method of the present invention, two types of polyester fibers having different spinning speeds are combined to obtain a mixed shrinkage yarn, and in this case, the relationship between the spinning speed of the yarn and the water swelling and shrinkage rate is important. That is, when polyethylene terephthalate is melt-spun in the present invention, its water swelling and shrinkage rate is as shown in FIG.
It changes rapidly after 00 m/min. Therefore,
Yarn B spun at a speed of 4000 m/min or less has a high water swelling and shrinkage rate, and is then stretched between hot rollers and the 20th roller to achieve uniform and stable physical properties! 1. Further, the yarn spun at a speed of 4000 m/min or more has a low water swelling and shrinkage rate and therefore does not require any drawing treatment, so a cold roller that does not require heating may be used.

(Example) [Polyethylene terephthalate having a limiting viscosity (η) of 0.68 was melted at 290°C and melt-spun from two sets of spindles each having 86 prototype spinning holes, followed by direct spinning and drawing as shown in Figure 1 Iζ. Different shrinkage mixed fiber yarn was obtained using the device.

In the same device, the surface temperature of the hot roller was 80°C, the surface temperature of the second roller was 90°C, the air pressure supplied to the interlace nozzle was 5 J/m2, and the number of entangled parts was 15/m2. Met. Table 1 shows the results when the spinning speed of yarns A to H was varied depending on the rotational speed of the cold roller and hot roller.

(Left below) (Effects of the Invention) As described above, according to the present invention, it is possible to produce differentially shrinkable mixed fiber yarn with high efficiency without significantly changing the conventional direct spinning/drawing apparatus. The obtained mixed fiber yarn has uniform and stable physical properties and also has a soft texture peculiar to high-speed spinning, so the usefulness of the present invention is obvious.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the process of the present invention, and FIG. 2 is a diagram showing the relationship between the spinning speed and water swelling and shrinkage rate of polyethylene terephthalate. 14.18... Mouthpiece, 4... Cold roller, 5... Hot roller, 7... 20th-ra,
9...Interlace nozzle.

Claims (3)

[Claims] (1) By spinning polyethylene terephthalate from at least two spindles into two or more yarn groups, drawing at least one yarn group, and doubling the remaining yarn groups without stretching. When obtaining a mixed fiber yarn, yarn A spun from one spindle was spun at a spinning speed of 4000 to 6000 m/mi.
The yarn B spun from the other nozzle was taken up by an unheated cold roller so that the spinning speed was 1000 to 400.
The yarn is taken up by a hot roller so that the speed is 0 m/min, and then both yarns A and B are fed to a second roller that rotates at substantially the same speed as the cold roller, and then subjected to a mixed fiber entangling treatment. A method for producing differentially shrinkable blended polyester yarn. (2) The method according to claim 1, wherein the ratio of spinning speeds of yarn A and yarn B is 1.5 to 4. (3) The method according to claim 1, wherein the surface temperature of the second roller is 100°C or less.