KR920008967B1 - Process for the preparation of shaped fibers - Google Patents

Abstract

polyester resin containing more than 85 % of reacted compn. of at least one sort of terephthalic acid or its ester and at least one sort of alkylene glycol with polamide resin; spinning the polymerized compn., solidifying, bundling by guide in a way the cross-sectional shape of a fiber among bundles of the same shape fibers satisfies equation of 3 x (A/π)0.5 <= P/π [A; cross sectional area of a fiber, P; length of fiber cross sectional circumference , while the cross-sectional shape of a fiber among bundles of different shape satisfies equation Ai; >= 1.5 x Aj [Ai=Aj= cross sectional area of a arbitrary fiber ; heat-treating at temp. of more than Tm-10 deg.C and less than Tm + 50 deg.C (Tm; melting temp.) for at least 0.001 sec. at the site within 140 cm from solidifying point.

Description

Method of manufacturing a release cross section fiber

The present invention relates to a method for producing a release cross-section fiber. More specifically, it relates to a method of improving the physical properties and manufacturing process of the fiber by heat treatment at any stage from the spinning of the cross-sectional fiber until the spun polymer material is solidified before winding.

Recently, the development trend of synthetic fiber has reached the limit of improving the physical properties by polymer modification, and is seeking a way out by the complexation of various modified fibers or the diversification of fiber types.

This phenomenon is represented by a series of development competitions, which are called new synthetic islands, and are widely spread as economic development methods in terms of cost and success rate.

Therefore, the demand for composite fibers or release cross-section fibers constituting them is increasing day by day, but not all problems have been solved from the producer's point of view.

That is, because the cross-sectional shape of the fiber is more characteristically deformed, the difference in the orientation in the cross-sectional direction is increased due to the difference in cooling rate for each part in the fiber cross-section, which is less problematic in the existing ○ -shaped or △ cross-section. In the post-process such as twisting or twisting, the distribution of the force applied to the fiber becomes uneven, which is often broken.

As a result, the quality of the produced yarn is degraded, and in severe cases, the yield that can be normally used is less than 50%, which leads to a disadvantage in that the manufacturing cost is greatly increased. However, the existing production method solves the problem to some extent by strict management level, but the productivity per person is inevitably reduced because it usually yields only 70 ~ 80% yield and manpower is continuously managed.

In order to solve this problem, the researchers carefully analyzed and analyzed the fractured part of the stretched section yarn drawing process. As a result of discovering the technology and examining various technical possibilities, the present inventors have arrived at the present invention which adds a step of reducing the difference in the degree of orientation in the cross-sectional direction between the spinning and drawing processes.

That is, in spinning the cross-sectional fiber, the melting temperature (Tm) of the polymer used at a proper position within 140 cm from the freezing point by connecting single yarns using a guide from a position from the bottom of the position where the spun polymer material is solidified to before the heat treatment part. ) Is a method for producing a release cross-section fiber, characterized in that the heat treatment for at least 0.001 seconds at a temperature of Tm-10 ℃ or more Tm + 50 ℃ or less based on) When the forms of are all the same, the cross section of the fiber is represented by the following general formula (1).

(Where A is the cross-sectional area of the fiber and P is the length around the cross-section of the fiber)

It means that it is in the range which satisfies, and when the form of several single yarns radiate | emitted from one nozzle contains a different thing, at least 1 or more of them is represented by following General formula (2)

Where A _i and A _j are the cross-sectional areas of any single yarn

It means that it is in the range to be satisfied.

In manufacturing the fiber according to the present invention, the heat treatment portion needs to be performed at a position within 140 cm from the solidification point, and more preferably within 100 cm. After this range, the temperature of the single yarn drops to about room temperature, so the effect of heat treatment is not obvious, and since the energy of the heat treatment part is concentrated only on the surface, the surface and the internal disproportionation agent are not good.

The temperature of the heat treatment portion is preferably Tm-10 ℃ or more Tm + 50 ℃ or less, more preferably Tm or more Tm + 30 ℃ or less of the polymer used. Outside this range, if the temperature is low, rather promote the crystallization to increase the disproportion between the center and the outside of the cross-section, when the temperature is high, it is not good because the site where the energy is concentrated melts and destroys the shape of the heteromorphic single-sided surface.

In addition, the heat treatment should be able to be carried out for at least 0.001 seconds, if less than that of course it can not supply the required energy is not effective. However, in the case of a section having a low release rate, the difference in cooling rate for each part in the general manufacturing conditions is not so large, so the improvement of the method of the present invention is hardly seen and at least a release in a range satisfying the general formula (1) or (2). The effect can only be seen in single-sided yarns.

The polymer fiber having such a sectional cross-sectional effect may be applied to not only polyester-based but also polyamide-based fibers.

For example, the present invention will be described below.

Example 1

A polyethylene terephthalate resin having a melting temperature (Tm) of 265 ° C. was spun into 24 short fibers using a conventional spinning equipment and a nozzle for a release cross-section fiber, and after being heat-treated for 0.001 second at a position of 80 cm from a solidification point at 285 ° C. It was.

Fibers thus wound do not yet have sufficient crystals and fiber structure and thus have been drawn to obtain 75D / 24F complete fiber.

The fiber produced was evaluated as a sectional cross-section yarn with a distinct Y-shape of average cross-sectional area (A) of 0.0305 mm ² and average cross-sectional length (P) of 1.4237 mm.

The manufacturing processability was regarded as a defect phenomenon in which at least one of the 24 short fibers was broken in the drawing process, and when a defect occurred at least once until 1 kg of the stretched fiber was wound, it was excluded from the regular product.

As a result, 53 out of 56 products of 1kg each were judged as regular products, and the yield of the product was 94.6%, which was very good.

Example 2

A 75D / 24F fiber was prepared under the same conditions as in Example 1 except that the heat treatment was started at a position of 130 cm from the freezing point. The average cross-sectional area (A) of the fabrics produced was 0.0306mm ² , the length of the average cross-section (P) was 1.4582, and the yield of 1 kg product was 89.1% for 64 production.

Example 3

Except for setting the heat treatment temperature to 300 ° C, 55 kg of 1 kg products were produced under the same conditions as in Example 1 to obtain a regular product having a yield of 90.9%. It was found that the Y-type had a good release cross section with an average cross-sectional area (A) of 0.040 mm ² and a length (P) of 1.4104 mm of the prepared fiber.

Comparative Example 1

Fibers were prepared under the same conditions as in Example 1 except that the heat treatment of the present invention was not performed at all. The average cross-sectional area (A) of the fabrics produced was 0.0307 mm ² , and the average cross-section length (P) was 1.4573 mm.

Comparative Example 2

Fibers were prepared under the same conditions as in Example 1 except that the heat treatment portion started from the bottom of 160 cm from the freezing point. The average cross-sectional area (A) of the fabrics produced was 0.0306 mm ² , and the length of the average cross-section (P) was 1.4604 mm.

Comparative Example 3

Fibers were prepared under the same conditions as in Example 1 except that the heat treatment temperature was 320 ° C. The cross-sectional shape of the manufactured fiber was not the desired shape, such as the part is melt-bonded and the end is crushed, and the yield was only 17, 42.5% of 40 1kg products.

[Comparative Example 4]

46 1kg products were manufactured under the same conditions as in Example 1 except that the length of the heat treatment portion was adjusted to 5 cm and the heat treatment time was 0.0005 sec at a winding speed of 6000 m / min, but the yield was not very good at 69.6%. .

[Comparative Example 5]

In the manufacture of 75D / 24F fiber having a circular cross section using the same polymer as in Example 1, the heat treatment of the present invention was not performed at all and the heat treatment was performed as in Example 1, respectively. Yields of% and 94.8% were obtained.

In this way, when the cross section is circular, the improvement of product yield is evaluated as a level that is not so remarkable.

Claims (5)

In preventing the release cross-section fibers, the melting temperature (Tm) of the polymer used, from the position below the position where the spun polymer material is solidified, to the single yarns using a guide from a position from before the heat treatment portion and from within 140 cm from the freezing point Method for producing a release cross-section fiber, characterized in that the heat treatment for at least 0.001 seconds at a temperature of Tm-10 ℃ or more Tm + 50 ℃ or less on the basis of. The form of the fiber cross-section of one strand of single yarns of the same type which is radiated and connected from one nozzle as a measure of the cross-sectional fiber of claim 1 3 x (A / π) ^0.5

P / π (Wherein A is the cross-sectional area of the fiber and P is the length of the cross-sectional area of the fiber). The method of claim 1, wherein at least one single yarn is formed by the following equation when the types of single yarns radiated from one nozzle are different from each other as a measure of the cross-sectional fiber. A

1.5 × A _j (Wherein A _i and A _j are the cross-sectional areas of any single yarn). The release cross section according to claim 1, wherein the polymer material is a polyester-based resin having 85% or more of the components reacted with at least one terephthalic acid or ester-forming derivative thereof and at least one alkylene glycol. Method of making fibers. The method for producing a release cross-section fiber according to claim 1, wherein the polymer material is a polyamide-based resin.