KR19990009087A - Method for producing single component hollow spontaneous crimped fiber with excellent compressive recovery - Google Patents

Abstract

The present invention is characterized in that the melt-spun using a single-component fiber-forming polymer is produced by spinning in a hollow spinneret of the asymmetrical form of the slit left, right. One of the hollow spinnerets used in the present invention is that the left and right slits are semi-circular slits with large and small radii, and one is a curved slit and the other is a wing slit.

The present invention is a spinneret with a simple structure is excellent in crimping and compressive recovery force, no bending occurs during the spinning process, it can be produced a yarn with a large hollowness.

Description

Method for producing single component hollow spontaneous crimped fiber with excellent compressive recovery

The present invention provides a single component hollow fiber crimp having excellent compression recovery ability by melt spinning a single component through a hollow spinneret having an asymmetric slit to exhibit the same characteristics as a conventional two component spontaneous crimp fiber. It relates to a method for producing a fiber.

In general, when multi-component polymers with different properties such as shrinkage are spun together to form a single fiber, a composite fiber in which a cross section of a single filament is formed into an eccentric sheath-core or side by side type Has latent crimping properties, and loose heat treatment results in uniform spiral high crimping properties.

Conventional methods for producing crimped composite fibers using this principle can be broadly classified into three types. First, the fabrication of composite fibers expressing high crimping properties by mixing fibers having different shrinkage properties in a biaxial blending method Method (Japanese Patent Application Laid-Open No. 59-216934), second, a method of manufacturing by spinning a polymer of heterogeneous (2 種) polymers of different properties into a single fiber (Japanese Patent Application No. 51-67421), and third, an in-situ polymer. There have been proposed a method for producing a composite fiber in which high copolymer properties are expressed by using the other copolymer as the first component and the second component (Japanese Patent Application Laid-Open No. 51-116220).

However, the first method above, the method of manufacturing a composite fiber of the bishrink mixed fiber method is a method of stretching the heat shrinkage at the time of stretching based on the properties of the polymer of the same composition, and then the air crimped composite to express the crimp The process and the speed of drawing about the fibers of the slow, the air entanglement composite method has a disadvantage in that the productivity is lowered. In addition, the manufactured composite fiber has uneven crimp expression and weak adhesion between the fibers, so that the crimp durability is reduced, such as separation or reduction of crimp characteristics due to the external force applied to the fiber during processing and post-processing. It has a shortcoming.

The second method, a method for producing a composite fiber composed of heterogeneous polymers, for example, a method for producing a composite fiber by using a composite spinning method using polyether and polyamide, is based on the imbalance of thermal properties and the dyeability of the positive components. Due to the low adhesion at the interface due to uneven dyeing and low compatibility between polymers, interfacial separation occurs due to external force applied to the fiber after spinning. In the process of forming the hollow portion by the melt viscosity difference of the hollow portion toward the material with a large melt viscosity, eccentricity, shrinkage (see Figure 4), so it is difficult to expect high repulsion and excellent compression recovery. Recently, as a way to solve the above problems due to the separation of the abnormal minutes, it is proposed to make the cross-sectional shape of the bicomponent composite yarn into an eccentric sheath-core shape instead of a side-by-side shape (Japanese Patent Application Laid-Open No. 52-124925). In this case, compared to the side-by-side type, the crimping characteristics are poor, the hollow part for improving the resilience and compression recovery ability cannot be formed, and the spinneret for manufacturing the fiber is complicated, and the fabrication workability is also poor.

Third, the method of manufacturing crimped composite fiber using two-component characteristic difference using in-situ copolymer is better than that of the above, but the characteristic difference between two components is increased to improve crimping. In this case, the compatibility is low, and there are problems in the weaving process such as the generation of curvature in the spinneret during spinning. Also, as in the case above, a material having a high melt viscosity in the process of forming the hollow part by the melt viscosity difference of the positive component It is difficult to expect high repulsion and excellent compression recovery because the hollow part is eccentric and reduced. In addition, spinnerets also have complex disadvantages because they are complex.

The present invention is to solve the problems of the prior art as described above by spinning a single component fiber-forming polymer with a simple spinneret device to exhibit high repulsion and excellent compression recovery by the hollow part with spontaneous high crimping characteristics At the same time, there is no curvature, and the purpose is to provide a manufacturing method excellent in spinning workability.

1 is (a), (b) is a plan view of the spinneret used in the present invention.

Figure 2 is (a), (b) is a cross-sectional view of the fiber produced by the spinneret above.

3 is a plan view of the spinneret used in the comparative example.

4 is a cross-sectional view of the fabric made of the detention used in the comparative example.

The present invention relates to a method for producing a single-component hollow winding fiber with excellent compression recovery, and has a hollow portion in the center of the fiber, but the fiber-forming polymer with a mold designed to have a heterogeneous shear history in one region when passing through the slit Melt-spinning has different orientation and heat shrinkage characteristics similar to side by side hollow cross-section fibers in the longitudinal direction of the fiber. It relates to a manufacturing method characterized in that the compression recovery force is exerted.

The present invention will be described in more detail as follows.

In general, the hollow spinnerets for hollow use have a form of detention in which two to four curved slits are arranged at the edges of symmetrical shapes such as circular, triangular, and square, but in the present invention, a single component is used, but the left and right asymmetric slits of the fibers are arranged. It is characterized in that the spinneret is used to change the orientation and heat shrinkage characteristics between the left and right. Detention slit is usually used as a semicircular slit (1), one of the left and the right, but the other side is a semicircular slit (2) larger than the radius of the opposite slit ((a) of Figure 1, or one curved) There is a method (Fig. 1 (b)) in which the mold slit 3 is used and the other is a wing-shaped slit 4.

In general, if the shape and position of the curved slits are different as in (a) above, the upper part of the inner slit tries to maintain the same pressure on both the left and right sides. Therefore, the left and right curved slits are discharged differently until the final winding. Both sides have heterogeneous draft ratios, resulting in different molecular chain orientations and thicknesses.

In addition, if the tension or stress is concentrated in the thicker part in the stretching process, the thicker part is further stretched, and the thermally treated yarns having different molecular orientations have different molecular orientations. A spiral crimp is expressed.

As shown in (b) of FIG. 1, the wing-shaped slit has a larger orientation difference than the above-mentioned curved slit. In the sharp part, the shear rate is larger than that of the wing area, so the amount of ejection from the pointed area is much larger. As a result, the draft ratio is changed as in the above case.

In the case of (a) of FIG. ₁ , the larger the difference between the radius (r ₁ ) and (r ₂ ) of the two semicircular slits, the larger the difference between the width (W ₁ ) of each slit, or the central angle (θ ₁ ) of the slit Smaller values increase spontaneous crimping and can be adjusted to give the desired degree of crimping. In case of ( _b ) of FIG. 1, the crimping property increases as the width W ₂ of the wing-shaped slit is smaller, the smaller the size of the inner angle θ ₂ is, or the length L of the slit is longer. 2 (a) and 2 (b) show the cross-sectional shape of the yarn manufactured using the spinneret of FIG.

Example 1

A polyethylene terephthalate polymer having a weight average molecular weight of 6.5 × 10 ⁴ prepared by a conventional method is melt-extruded at a temperature of 280 ° C., with a radius difference of 0.2 mm, a slit width difference of 0.05 mm, and a center angle of 60 °. After unfolding through 36 spinneret using a spinneret, and wound at a constant speed to produce an unstretched filament, the stretching process is carried out under a draw ratio of 3.0 times, stretching temperature 110 ℃ / 190 ℃, After stretching, the relaxation heat treatment was performed for 5 minutes by moist heat of 80 ℃.

Example 2

As in Example 1, but using a detention hole with a radius difference of 0.15 mm.

Example 3

As in Example 1, but the use of a detention hole having a slit width of 0.02 mm.

Example 4

As in Example 1, but using a detention hole having a center angle of 120 °.

Example 5

A slit width of 0.15 mm, a slit length of 1.5 mm and a size of 60 degrees of the cabinet were used as in Example 1 using the detention hole of FIG.

Example 6

As in Example 5, the detention hole of FIG. 1 (b) having a slit width of 0.18 mm was used.

Example 7

As in Example 5, but using a detention hole having a size of 90 ° inside the cabinet.

Example 8

As in Example 5, but a detention hole having a length of 1.0 mm was used.

Comparative Example

The first component is polyethylene terephthalate having an intrinsic viscosity of 0.85, and the second component is polyethylene terephthalate having an intrinsic viscosity of 0.52. The intrinsic viscosity of the positive component is 0.33 and the melt viscosity at spinning temperature is 1,730 poise. . Spinneret was used as shown in Figure 3, other conditions were prepared in the same manner as in the above embodiment.

Compression elasticity; According to KS K 2617 (Cotton Duvet Cotton Testing Method), a sample of 20 × 20 cm was used to determine the compressibility and the bokhwa ratio.

Volume recovery by drying; Samples were measured in a size of 20 × 20 cm according to KS K 2617 (Cotton Duvet Cotton Testing Method).

Crimp numbers C1, C2; Take a sample of short fibers and make 10 copies of 5cm at a superload of 0.05g / d without tension as much as possible, and then magnify with a microscope to measure the super-load crimp number (inch / inch) C1. After removing and leaving for 30 seconds under no tension, the external crimp number C2 is measured.

Tables 1 and 8 show the characteristics and the yarn drawing workability of the yarns prepared in Examples 1 to 8 and Comparative Examples.

TABLE 1

Yarn Characteristics and Workability

※ ◎ excellent; Good; △ normal; × bad

Unlike the conventional method, the present invention avoids complicated spinnerets by using a single component, and solves the problems of curvature occurrence, deterioration of radio workability and compatibility caused by the use of two components. In addition, by having a hollow in the center of the fiber to increase the compression recovery. In addition, the invention has a high resilience and excellent resilience because the conventional defect that the hollow portion is eccentric, ignited to the material with a large melt viscosity in the process of forming the hollow portion by the difference in melting viscosity of the positive component when using the two components Demonstrates compressive recovery.

Claims (3)

A method for producing a single component hollow spontaneous crimp fiber having excellent compression recovery, characterized in that the single component fiber-forming polymer is melt-spun through a hollow spinneret having a slit of right and left asymmetrical forms. The step of claim 1, wherein the left and right asymmetric hollow spinning dies have superior radius recovery force, characterized in that the radius r ₁ of one semicircular slit 1 is smaller than the radius r ₂ of the other semicircular slit 2. Component Hollow spun winding fabric. The single component hollow spontaneous crimp according to claim 1, wherein the left and right asymmetric hollow spinnerets have a curved slit (3) on one side and a wing slit (4) on the other side. Method of making fibers.