JP2591715B2 - Method for producing different shrinkage blended polyester yarn - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for obtaining a different shrinkage mixed fiber using a direct spin drawing method in which drawing is performed immediately after spinning.

(Prior art) In recent years, in obtaining polyester fiber, a direct spinning drawing method in which melt-spun undrawn yarn is supplied directly to a drawing step without being wound once on a bobbin or the like, and is produced at low cost, has been proposed. Proposed. On the other hand, in order to improve the flat feeling peculiar to synthetic fibers and obtain a bulky feeling, it is widely used to use different shrinkage mixed yarns composed of yarns having different boiling water shrinkage rates.

Japanese Patent Laid-Open Nos. Sho 60-126316 and Sho 59-126316 produce such different shrinkage mixed fibers using the direct spinning and drawing method.
It is disclosed in Japanese Patent Publication No. 130309.

(Problems to be Solved by the Invention) However, the invention of Japanese Patent Application Laid-Open No. 60-126316 discloses a method for imparting a difference in drawing conditions to a high-speed spun yarn having a spinning speed of 5100 m / min or more to obtain a difference in shrinkage ratio. Are unstable and tend to cause defects such as spots.

Also, the invention of JP-A-59-130309 has a low spinning speed (winding speed) of 3600 to 4800 m / min, resulting in poor productivity.
Also, within such a spinning speed range, a large difference in shrinkage ratio cannot be obtained, so that the difference in heat treatment changes the shrinkage ratio, which complicates the process.

An object of the present invention is to solve such a problem, and it is an object of the present invention to easily produce a different shrinkage mixed fiber having stable physical properties by using a highly efficient direct spinning and drawing method.

(Means for Solving the Problems) The present invention relates to a method for producing polyethylene terephthalate at least
Each of the two spinnerets is spun into two or more yarn groups, at least one yarn group is stretched, and the remaining yarn groups are twisted without being stretched. The yarn A spun from the die is picked up by a non-heated cold roller so that the spinning speed is 4000 to 6000 m / min, and the yarn B spun from the other die is hot so that the spinning speed is 1000 to 4000 m / min. After the yarns A and B are supplied to a second roller that rotates at substantially the same speed as that of the cold roller, a blending and entanglement process is performed.

The polyethylene terephthalate used in the present invention contains ethylene terephthalate as a main repeating unit, and may be a modified polyethylene terephthalate obtained by copolymerizing about 15 mol% or less of other components.
Polyethylene terephthalate has an intrinsic viscosity before spinning (measured at 25 ° C dissolved in orthochlorophenol).
A value of about 0.63 is appropriate.

In the present invention, such polyesters are melt spun from at least two different spinnerets, each separately oiled and taken off. At this time, the spinning speed, which is the running speed of the yarn on the surface of the cold roller and the hot roller that performs take-up, is 4,000 to 6000 m / min for one yarn A, and the other yarn B
Takes over so that it becomes 1000-4000m / min. Thread A
If the spinning speed is less than 4000 m / min, not only productivity will be reduced, but also the orientation of the yarn will not be sufficiently increased, and the texture of the woven or knitted material will become hard due to the heat treatment at the time of post-processing or dyeing, which is not suitable. If the spinning speed of the yarn B is out of the range, the draw ratio becomes inappropriate, and not only the spinning properties are deteriorated, but also the shrinkage of boiling water with the yarn A decreases, and a bulky feeling is obtained. Not suitable.

Further, the roller for picking up the yarn A is a cold roller having a surface temperature of room temperature and not subjected to a positive heat treatment, and the roller for picking up the yarn B has a surface temperature of the glass transition point temperature of the yarn of -20 to +30. Use a hot roller actively heated to the area.

Next, the pulled yarns A and B are aligned and provided to the second roller. The temperature of the surface of the second roller is preferably 100 ° C. or less. If the surface temperature of the second roller is 100 ° C. or more, the shrinkage of the yarn B in boiling water is remarkably reduced, which is not suitable. Furthermore, the surface temperature of the second roller may be room temperature, but is preferably 70 ° C. because the package is tightly wound.
It is better to do above. Further, the second roller rotates at substantially the same speed as the cold roller. For this reason, the stretching action is not 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. It is preferable that the ratio of the spinning speed between them is also about 1.5 to 4.

Next, the yarns A and B passing through the second roller are subjected to a mixed and entangled process of giving a entangled portion of about 15 to 20 pieces / m with a fluid such as air to form a mixed fiber.

Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 is a schematic view showing the steps of the method of the present invention. Among the yarns spun from the die (1A) (1B), the yarn A picked up at a high speed is reduced at a low speed by an oiling nozzle (2). The yarns B to be picked up are separately applied with an oil agent by the oiling roller (3). Next, the yarn A passes through the semi-peripheral surface of the mirror-finished cold roller (4), and then the yarn B
Is surrounded by a hot roller (5) and a separate roll (6) at least once, and is drawn at the spinning speed as described above and then aligned. Both yarns A and B are aligned with the second roller (7) and the second roller (7).
It is heat-set by surrounding the separate rolls (8) one or more times, and mixed and entangled by the interlace nozzle (9) and wound around the bobbin (10).

(Operation) In the method of the present invention, two types of polyester fibers having different spinning speeds are combined to obtain a different shrinkage mixed fiber, but in such a case, the relationship between the spinning speed of the yarn and the shrinkage ratio of boiling water is important. That is, when polyethylene terephthalate is melt-spun in the present invention, its boiling water shrinkage ratio is as shown in FIG.
It changes abruptly at 00m / min. Therefore, 4000m / min
The yarn B spun below has a high boiling water shrinkage ratio, and is then stretched between a hot roller and a second roller so that it also has uniform and stable physical properties. Also 4000
Since the yarn A spun at m / min or more has a low boiling water shrinkage ratio, no particular drawing treatment is required, and therefore a cold roller which does not require heating may be used.

(Example) Polyethylene terephthalate having an intrinsic viscosity (η) of 0.63 was used.
It was melted at 290 ° C. and melt-spun from two sets of die having 36 round spinning holes, respectively, to obtain a different shrink mixed fiber using a direct spinning and drawing apparatus shown in FIG. In this apparatus, the surface temperature of the hot roller is 80 ° C, the surface temperature of the second roller is 90 ° C, and the air pressure supplied to the interlace nozzle is 5 kg /
m ² and the number of entangled portions was 15 pieces / m. Table 1 shows the results when the spinning speed of the yarns A and B was changed according to the number of rotations of the cold roller and the hot roller.

(Effects of the Invention) As described above, according to the present invention, it is possible to manufacture a different shrinkage mixed fiber with high efficiency without significantly changing the conventional direct spinning and drawing apparatus, and furthermore, to obtain the obtained mixed fiber. The fiber has uniform and stable physical properties and a soft feeling unique to high-speed spinning, and the usefulness of the present invention is apparent.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing the steps of the present invention, and FIG. 2 is a diagram showing the relationship between the spinning speed of polyethylene terephthalate and the boiling water shrinkage. 1A, 1B: Base, 4: Cold roller, 5: Hot roller, 7: Second roller, 9: Interlace nozzle.

Claims (3)

(57) [Claims] 1. The method according to claim 1, wherein the polyethylene terephthalate comprises at least 2
Each of the two spinnerets is spun into two or more yarn groups, at least one yarn group is stretched, and the remaining yarn groups are twisted without being stretched. The yarn A spun from the die is picked up by a non-heated cold roller so that the spinning speed is 4000 to 6000 m / min, and the yarn B spun from the other die is hot so that the spinning speed is 1000 to 4000 m / min. A differently shrink-blend polyester yarn, wherein the yarn A and B are fed to a second roller which rotates at substantially the same speed as the cold roller, and then the fiber is entangled. Manufacturing method. 2. The yarn A and the yarn B have a spinning speed ratio of 1.5 to 1.5.
4. The method of claim 1 wherein the method is 4. 3. The method according to claim 1, wherein the surface temperature of the second roller is 100 ° C. or less.