JPS6050885B2 - Method for manufacturing high bulky yarn - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for producing a high bulky yarn by drawing and stringing undrawn synthetic fibers.

(Prior art) Conventionally, the method of obtaining high bulky yarn from undrawn synthetic fibers is to draw the yarn normally and then cut or cut the stable into two parts, one of which has the same shrinkage rate without being heat-treated. A common method for producing high bulky yarn is to heat-treat the yarn to reduce the shrinkage, and then mix the two to make a spun yarn, thereby creating a mixture of shrinkage rates in the yarn.

(Purpose of the invention) In the conventional high bulky yarn production method, when two types of staples with different shrinkage rates are not uniformly mixed when turned into yarn (for example, when only high shrinkage or only low shrinkage is hardened), , the final yarn obtained is not a uniform yarn.

Therefore, strict control is required for such equalization. The present invention has been devised to produce an excellent high bulky yarn that does not require such management. (Structure of the Invention) The present invention provides a roller for supplying an end-drawn synthetic fiber filament, a roller that rotates at a circumferential speed greater than the circumferential speed of the supply roller and draws the filament between the supply roller and the supply roller. a heating means installed and extending along the yarn path from the roller to the drawing roller, and the heating means is located on the supply roller side and extends in the yarn path direction while maintaining a gap with the yarn path. Stretching the fiber at a lower stretching ratio than the usual stretching ratio using a stretching device having a contact heating section connected to the tip of the stretching roller side of the preheating section and causing the fiber to run in contact with each other. It is a high bulky yarn characterized in that it is then heat-shrinked to form high-elongation, low-shrinkage fibers, and then this fiber is woven.

7 (Principle of action) In view of the above points, we devised a way to create a shrinkage difference in the fibers without mixing staples that have a shrinkage difference.
We focused on the fact that when the filaments are pulled apart, the extent to which they are stretched before being torn off varies among single fibers.

That is, the elongation of the single fiber before it is cut reaches its maximum before and after the tearing point, and once it is cut, it is gradually elongated again until it reaches the breaking elongation, but the elongation is not uniform depending on the location. In other words, it is the same as changing the draw ratio for each part of the fiber, and if the draw ratio changes greatly, the shrinkage rate will naturally change as well. However, in normal tension cutting, the supplied fibers are completely stretched, so during early tension cutting, there is little room for elongation before breaking, and in reality, there is almost no difference in shrinkage. .
The present invention is different from the conventional method in that it leaves as much room as possible for the fibers to be stretched during tension cutting, so that the fibers can be easily stretched. To explain using a specific example, the first
The figure is a front view showing one embodiment of the present invention.

In the figure, an undrawn fiber Y stored in a supply can 1 is pulled out by a supply roller 3 consisting of a pair of nip rollers 3a and 3a'' through a guide 2, and is pulled out by a pair of nip rollers 4
A and 4a'' are supplied to a stretching roller 4.The stretching roller 4 rotates at a circumferential speed of a predetermined stretching ratio relative to the supply roller 3, and stretches the filament Y between both rollers.

A heating means 5 is provided along the yarn path between the supply roller 3 and the stretching roller 4, and includes a preheating section 5a and a contact heating section 5b.
Consisting of

The preheating section 5a is located close to the supply roller 3 and extends in the direction of the yarn path while maintaining a gap with the yarn path of the filament. The contact heating section 5b is connected to the tip of the preheating section 5a on the stretching roller 4 side,
The filaments Y are made to run in contact. The contact heating portion 5b preferably has an arcuate cross section with a radius of curvature γ as shown in the figure.
This radius of curvature γ is 57707! ~60mm.
is preferred. The heating means 5 may uniformly heat the preheating section and the contact heating section, or may provide a temperature difference or a temperature gradient. While the undrawn fiber Y pulled out from the supply can 1 travels from the supply roller 3 toward the drawing roller, it is preheated in the preheating section 5a of the heating/heating means 5, and is gradually crystallized until it reaches the contact heating section 5b. contact, and a stretching point is fixed to the contact portion.

Therefore, since the undrawn fiber is preheated and then stretched with a fixed drawing point, the fiber Y is drawn without being cut and with the drawing point constant, so that no drawing unevenness occurs even at low magnification. . That is, if the stretching ratio is simply lowered in an attempt to increase the elongation, the result will be so-called thick-and-thin stretching, which will result in uneven stretching and will not produce a proper fiber, but in the case of the present invention, a sufficiently low stretching ratio is possible. . The lower the stretching ratio, the better; for example, it is preferably 0.8 times or less of the predetermined stretching ratio. The filament drawn in this manner is heat-set by a contraction heat setting means J6, and then tension-cut between a take-up roller 7 and a tension-cutting roller 8.

This shrink heat set has two meanings.

One of them is to shrink the drawn fibers to further increase the elongation margin. The method of the present invention prevents variegation. Because we have devised a way to stretch the fibers at a low magnification so that the fibers are stretched at a low magnification, the fibers can be stretched easily, but if the magnification is too low, uneven stretching will occur and there will be a limit, so shrinking is done here to further increase the margin for stretching. Therefore, the higher the shrinkage rate, the better, as long as it does not cause trouble in the process, for example, 10% or more, preferably 20%.
It is better to do more than that. The second purpose of this shrink heat set is
The reason lies in the reduction in the shrinkage of the filaments.

In other words, when the filament is stretched during tension cutting, internal strain occurs and the shrinkage rate increases, which causes a shrinkage difference between the unstretched part and creates bulkiness, but the unstretched part causes bulkiness. If the contraction rate of the filament (that is, the original filament) is high, even if the contraction rate is increased by elongation, the effect will be small. Therefore, the lower the shrinkage rate of the original filament, the more effective the difference in shrinkage due to elongation will be, so the more heat-setting it is, the better. For example, the boiling water shrinkage rate is 5% or less, preferably 2% or less. Then,
The fibers treated in this way are torn into strips by tension cutting,
It is made into short fibers.

Conventionally, fibers are cut in multiple stages to make them as even as possible, but when doing so, fibers with different physical properties are cut in multiple stages many times. By returning it, the unstretched parts are stretched and balanced, and the bulky effect is reduced. Therefore, in the present invention, if possible, use one-stage tension cutting as in this example, or limit it to two-stage tension cutting at most. It is desirable to keep it. Further, in this example, stretching, shrink heat setting, and tension cutting are performed in a series of steps, and after the stretching roller 4, a take-up roller 7 consisting of a pair of nip rollers 7a and 7b is provided between the stretching roller 4 and the take-off roller 7. A contraction heat setting means 6 is provided, followed by a tension cutting roller 8 which rotates at a circumferential speed of a predetermined magnification relative to the take-off roller 7 and cuts the filament in tension between it and the take-up roller 7. In addition, the tension roller 8
consists of a pair of nip rollers 8a and 8b. This can also be carried out by separating the steps as necessary. The short fibers obtained in this way are formed into yarn by adding drafting and twisting effects in the same way as conventional high-low shrinkage differential blended yarns, and after being converted into yarn or woven or knitted fabrics, they are heated to create high bulk. It is sufficient to produce a thread effect. (Effects of the Invention) According to the present invention, it is possible to obtain a beautiful bulky yarn without any concerns about blending unevenness and without any hanging, and moreover, it is economical because it can be produced with a simple device.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of the present invention, in which 3 is a supply roller, 4 is a stretching roller, 5 is a heating means, 5a is a preheating section,
5b is a contact heating section.

Claims (1)

[Claims] 1. A roller that supplies an undrawn synthetic fiber filament, a roller that rotates at a circumferential speed greater than the circumferential speed of the supply roller and stretches the filament between the supply roller and the yarn from the supply roller to the stretching roller. heating means extending along the road;
The heating means includes a preheating section located on the supply roller side and extending in the yarn path direction while maintaining a gap with the yarn path, and a contact heating section that is connected to a tip of the preheating section on the stretching roller side and causes the fiber to run in contact with the preheating section. Stretching the filament at a lower stretching ratio than the usual stretching ratio using a stretching device having a
Next, heat shrink treatment is performed to create high elongation and low shrinkage fibers,
A method for producing a high bulky yarn, which is characterized in that the fibers are then cut.