JPS641568B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for stretching and simultaneously twisting highly oriented undrawn yarns such as polyester. More specifically, the present invention relates to a method capable of stably performing the simultaneous stretching and twisting process at high speed and over a long period of time.

[Conventional examples and their problems]

In recent years, the speed of false twisting processing of polyester fibers has increased, and high-speed processing machines exceeding 600 m/min, especially friction false twisting machines, have become mainstream in the market. Most machines are equipped with a three-axis external type for the friction applying part.
As for the most important friction member for adding yarn, polyurethane disks are generally superior in terms of the quality of processed yarn obtained, but on the other hand, the durability of polyurethane disks has been highlighted as a major problem.

In other words, the previously known Tokuko Sho 39-
Even when the polyurethane of the flange-type false twister described in Publication No. 10688 was used in the disc of the above-mentioned triaxial circumscribed false-twister, the light resistance was poor and it could not be used stably for a long period of time, which was a big problem in practical use.

Therefore, the present inventors conducted intensive studies to improve the durability of disks whose main component is polyurethane, which has the highest quality of processed yarn.
We obtained the knowledge that the disk surface is degraded by light with short wavelengths below μ. In other words, the present inventors have already proposed that the problem of disk life can be greatly improved by covering the false-twisted disk portion to prevent such short wavelength light from irradiating the disk (see Japanese Patent Application Laid-Open No. Publication No. 54-11351) is
The threading operation becomes quite complicated, and the disk may be inadvertently exposed to short-wavelength light when storing or assembling it, so this problem has not been solved at all. is the current situation.

In particular, in simultaneous drawing and false twisting of highly oriented undrawn filament yarns, since the processing tension is high, the yarns tend to break at high speeds, and scratches on the disk surface can be a fatal defect.

Although many of those skilled in the art have recognized the above-mentioned problems, they have not yet been improved, and such improvements have been strongly desired.

[Object of the present invention]

In view of this, the inventors of the present invention have conducted further studies and have discovered the friction false-twisting disk of the present invention in which the light resistance of the disk itself has been positively improved. In other words, the present invention improves light resistance and durability by using a specific material of polyurethane as a disk, and also allows for high-speed processing without generating fuzz even when high tension is applied to the yarn during false-twisting at the same time as drawing. The purpose is to ensure stable machining over a long period of time.

[Configuration of the present invention]

The present invention has the following configuration.

``In drawing and simultaneously false-twisting highly oriented undrawn filament yarn, a triaxial circumscribed friction false-twisting device is used as the false-twisting device, and the following monomers are used as isocyanate components as the friction false-twisting disk of the friction false-twisting device. A method for simultaneously drawing and simultaneously false-twisting a highly oriented undrawn yarn, the method comprising simultaneously drawing and simultaneously false-twisting the polyurethane containing polyurethane as a main component.

(However, R ₁ and R ₂ are organic groups.) [Operations and effects of the present invention] In the present invention, a highly oriented undrawn filament yarn is stretched and simultaneously false-twisted. Since stretching and false twisting can be performed in one step, efficient production is possible. In addition, in the present invention, the processing speed is 600
It is preferable that it is more than m/min. This is to improve productivity.

Next, in the present invention, it is necessary to use a triaxial circumscribed friction false twisting device. This is because it gives a feeding effect to the yarn, does not increase tension even during high-speed processing, and does not generate fluff.

Next, in the present invention, as the isocyanate component of polyurethane, its main component is It is necessary to use a diisocyanate represented by (R ₁ , R ₂ : organic group). This is because it not only improves durability and light resistance, but also has favorable friction properties, hardness, etc., allows stable production, and provides a high-quality temporarily twisted yarn.

The above isocyanates are industrial &
Engineering Chemistry.Vol6No.1, March.1967
pages 12 to 19 of 2006, it is known to be used as an elastomer. However, polyurethane containing such an isocyanate is not known to have any properties such as being used for friction materials or having excellent light resistance, and this is the first attempt in the technical field of the present invention, that is, in the textile industry.

The disc of the present invention uses polyurethane obtained by polymerizing the isocyanate component and polyol as at least the twisting member of the friction false twist disc. Any polyether or copolymer may be used. Adipic acid, phthalic acid, etc. are used as the polyester. Further, as the polyether, polytetrahydrofuran, ethylene oxide, etc. are used.

Of course, in the present invention, the isocyanate component is
It goes without saying that 100% of the monomer does not necessarily have to be the monomer represented by the above formula, and other monomers may be included within the range that does not impair the effects of the present invention. Further, copolymerizing polyester is a preferred embodiment because it improves the abrasion resistance and false twisting properties.

The above organic groups for R ₁ and R ₂ are particularly preferably alkyl groups. Furthermore, it appears that R ₁ and R ₂ in the ortho position relative to the isocyanate group have a further effect of improving light resistance.

According to the findings of the present inventors, a polyurethane disc using tolidine diisocyanate as the above-mentioned isocyanate component exhibits the most remarkable effect of improving light resistance.

Next, it will be explained using drawings.

FIG. 1 is a sketch of a friction twisting device having three axes. a disk 6 mounted on shafts 3, 4, and 5 that rotate via pulleys 2 as the belt 1 runs;
The running thread 9 is twisted by the frictional force on the surfaces of the threads 7 and 8. The twisting action is controlled by the state of contact between the disks 6, 7, 8 and the running yarn 9, that is, the coefficient of friction and the yarn path. Therefore, in order to maintain stable false twisting over a long period of time, it is important that the surface conditions and shapes of the disks 6, 7, and 8 do not change as much as possible from their initial settings.

Figure 2 shows an example of disks 6, 7, and 8.
Core metal 1 made of aluminum or plastic
The polyurethane 11 of the present invention is adhered to the outer periphery of 0. The outer peripheral surface of the polyurethane 11 has a surface roughness suitable for stable and desired false twisting.
It is made with hardness and shape.

The friction twisting disk of the present invention is capable of obtaining uniform, high-quality textured yarn without impairing the twisting effect on the yarn, which is the original purpose of friction false twisting. Therefore, in the same procedure as normal friction false twisting, the life of the disk can be significantly extended, and the quality of the resulting textured yarn can be maintained stably for a long period of time.

Example 1 A polyurethane obtained by polymerizing tolidine diisocyanate and adipic acid polyester was molded into a disk shape to form the apparatus shown in FIGS. 1 and 2.

As a comparative example, commonly used naphthalene diisocyanate was used.

On the other hand, as a highly oriented undrawn filament yarn, a polyethylene terephthalate yarn having a birefringence Δn of 37×10 ⁻³ , a fineness of 127.5 denier, and a constituent number of filaments of 36 was used, and was subjected to indraw false twisting (false twisting at the same time as stretching). The stretching ratio was 1.70 times, the heater temperature was 210° C., and the number of false twists was 3400 T/m. Continuous long-term production was carried out under these conditions.

The point at which the wear of the disk progressed by 1% in terms of diameter was defined as the durability limit (life) of the disk. The degree of wear was determined as an average value for over 200 spindles, as there were many variations between devices and between spindles.

Comparing the two, the disk of the present invention had a lifespan approximately three times longer than that of the comparative product.

In other words, the comparative product had a lifespan of only 3.0 months, but the disk of the present invention had a lifespan of 9.0 months.
Durability has been significantly extended.

Furthermore, the obtained false twisted yarn had good product characteristics over a period of 9 months. On the other hand, in the comparative example
After 2.5 months, fluff, etc. appeared in the false twisted yarn, and the product was not satisfactory. Therefore, there was a difference of approximately 3.6 times in durability in terms of product yield.

[Brief explanation of drawings]

FIG. 1 shows an overall view of an example of a friction temporary twisting device using the polyurethane disk of the present invention. FIG. 2 shows a cross-sectional view of the polyurethane disc of the invention. 6,7,8,...polyurethane disk, 9...
... Running yarn, 10 ... Core metal, 11 ... Polyurethane part.

Claims (1)

[Claims] 1. In drawing and simultaneously false-twisting a highly oriented undrawn filament yarn, a triaxial circumscribed friction false-twisting device is used as the false-twisting device, and a friction false-twisting disk of the friction false-twisting device is used. A method for simultaneous stretching and twisting of highly oriented undrawn yarn, characterized in that polyurethane containing the following monomer as the main isocyanate component is subjected to simultaneous stretching and false twisting. (However, R ₁ and R ₂ are organic groups.) 2. Drawing of highly oriented undrawn yarn according to claim 1, wherein the organic groups of R ₁ and R ₂ are alkyl groups. Simultaneous false twisting method. 3. The drawing and simultaneous false twisting method of highly oriented undrawn yarn according to claim 1, wherein R ₁ and R ₂ are in the ortho position with respect to the isocyanate group. 4. Claim 1, characterized in that the isocyanate component is tolidine diisocyanate.
A method for simultaneously drawing and false-twisting a highly oriented undrawn yarn as described in 2.