KR840000778B1 - A process for producing a variable - Google Patents

Abstract

Irregular denier polyester filament is prepd. from several polymer melts transported at different speed. The melt is converged below the surface of the yarning nozzle; the speed and angle of the converging stream and selected so that the first stream may be transported more slowly, and be transported straight to the position where it contacts the second stream for the first time. The second stream moves faster to the position where it forms a bent loop. The second stream contacts with the first one on a straight-lined loop through the first stream elongation; and the resulting complex stream is quenched to produce the filaments.

Description

Method of Making Anomalous Denier Filaments

1 is a vertical sectional view of a preferred embodiment of a spinning nozzle usable in accordance with the present invention.

2 is a bottom plan view of the radiation nozzle of FIG.

3 is a graph of the radial velocity versus shrinkage used in the description of the principle underlying the form of the present invention.

4 is a cross-sectional view of the filament according to the present invention.

5 is a cross-sectional side view of the melt flow discharged from the spinneret of FIG. 1 for a form of the present invention.

6 is a graph illustrating the change of denier along a representative filament in accordance with an aspect of the present invention.

FIG. 7 is a graph illustrating the variation distribution shown in FIG. 5 with respect to the multi-orifice spinneret according to the aspect of the present invention. FIG.

The present invention relates to a method for producing an irregular denier polyester filament. In particular, the present invention relates to a spinning process that provides novel useful yarns which are spun by spinning two melts of the same polyester polymer.

BACKGROUND OF THE INVENTION A method for producing a magnetic crimped yarn which is produced by combining converging streams of other jet stretching, cooling the combined flow into filaments, and then stretching the fabric is known. Such prior art methods are described in US Pat. No. 3,387,327 to Privott et al. And US Pat. No. 3,497,585 to Chapman et al., Which are incorporated herein by reference.

By operating at speeds faster than those described in Freeboat et al., Chapman et al., It was found that improved methods and unique and useful products were provided.

The present invention provides a method for producing an irregular denier filament. This method produces a pair of fiber-forming molecular weight molten polymers that run at different speeds and collect them at a point below the spinneret surface, where the velocity of the stream and the angle to focus the stream are slower than the first of the stream. Choose to move nearly linearly after the first point of contact of the stream, and to form a loop that is bent back and forth between successive points in combination with the first one of the stream; Straightening the bent loop by the above-mentioned lengthening the first one so that the second one of the stream is in continuous contact with the first one of the stream; Then, the obtained composite flow rule is quenched to obtain a filament.

In another aspect of the invention, the first one of the class has a larger cross-sectional area than the second of the class. According to another aspect of the present invention, there is provided a method for producing a multifilament anomaly denier, characterized in that the method described above is simultaneously performed by supplying one common polymer source to one common spinning nozzle having a plurality of composite orifices. In this case, the geometry and spinning conditions of the composite orifice are chosen such that the filaments obtained have thick and thin sections continuously from the phase between the filaments and the filaments.

Another main aspect of the present invention provides a plurality of filament yarns characterized by non-round cross-sections, each of which is repeatedly changed in area by more than ± 10% depending on the length of the filament, the variation in the cross-sectional area of the filament Out of phase up to the filament. In another aspect of the present invention, the cross section is repeatedly varied by ± 25% (preferably ± 30% or more) according to the length of the filament.

In another form of the invention, the yarn has at least 2.5% U of the woster disproportionate.

In another form of the invention, the individual filaments are formed from a single molten polymer.

In another aspect of the present invention, there is provided a spinneret plate characterized by a composite orifice consisting of a capillary with a large cross-sectional area and a capillary with a small cross-sectional area, the capillary providing a communication portion between the surface of the plate and the opposite side of the plate and close to the surface. And the length of the capillary tube is selected so that the capillary tube having a small cross-sectional area is less resistant to polymer flow than the capillary tube having a large cross-sectional area.

Other aspects of the invention are apparent from the following description taken in conjunction with the accompanying drawings.

The present invention is specifically exemplified using polyester polymers, and it can be understood that certain forms of the present invention are generally applicable to melt spinnable polymers. As used herein, “polyester” refers to a fiber-forming polymer that can be produced by reacting at least 85% by weight of terephthalic acid with a dihydric alcohol. Polyesters are typically prepared by direct esterification of ethylene glycol and terephthalic acid, or by transesterification between ethylene glycol and dimethyl terephthalate.

1 and 2 illustrate preferred embodiments of spinnerets that can be used to obtain all forms of the invention. The spinneret comprises a large counterbore 20 formed on the upper surface 21 of the spinneret plate 22. The small counterbore 24 is formed at the bottom of the large counterbore 20. The large capillary tube 26 extends from the bottom of the large counterbore 20 on the opposite side of the small counterbore 24 and also connects the bottom surface 28 of the plate 22 with the bottom of the large counterbore 20. Doing. The small capillary 30 connects the bottom 28 of the counterbore 24 with the surface 28. Capillaries 26 and 30 are inclined 4 degrees from vertical and thus have an angle of 8 degrees. The counterbore 20 has a diameter of 0.0625 inches (1.588 mm) while the other counterbore 24 has a diameter of 0.031 inches (0.787 mm). The capillary tube 26 has a diameter of 0.0165 inches (0.419 mm) and a length of 0.150 inches (3.81 mm), while the other capillaries 30 have a diameter of 0.012 inches (0.259 mm) and a length of 0.0286 inches (0.726 mm). Have Lands 32 separate them as capillaries 26 and 30 exit the surface 28, and they also have a width of 0.056 inches (0.142 mm). Plate 22 has a thickness of 0.554 inches (14.07 mm). Capillary tubes 26 and 30, together with counterbore 20 and 24, form a joining orifice for spinning the various types of useful filaments of the present invention, as described in detail later herein. .

3 is a graph showing how the shrinkage ratio of the polyester filament fluctuates depending on the spinning speed when the jet operation is performed. The dashed curve shows the shrinkage rate when using spinneret capillaries with a diameter of 0.063 inches (1.6 mm), or when simultaneously producing 34 threaded filaments that are simultaneously flared and stretched to produce 34 filaments. Shows a drop from about 65% at 3400ypm (about 3100mpm) to about 5% at 5000ypm (about 4500mpm).

The solid line curve is used when spinnerets having a diameter of 0.015 inch (0.38 mm) are used, and when 150 strands of filaments are spun at the same shape to simultaneously spin 34 filaments. Indicates that the shrinkage drops at high speed. When capillaries of different diameters are used, there is one group of curves between the left and the right of the curves shown. Here the curve can be shifted by varying the amount of polymer produced (for a given capillary diameter). In other words, this curve can be shifted by varying the jet stretch, which is the ratio of the average melt polymer velocity in the capillary at the dead velocity immediately after solidification.

Preferably, the spinneret is configured such that the speed in one of the classes of capillaries differs in speed from 2.0 to 7 times (preferably 3.5 to 5.5 times) in the capillaries of the other class. More advantageous advantages are obtained when two fast streams have a smaller cross-sectional area than a slow stream. Productivity is increased when the spin rate is selected such that the shrinkage rate of the bonded filaments is less than 30%, and the productivity is maximum when the shrinkage rate is less than 10%.

The present invention, which can be used for melt-spinable polymers as a class, can be achieved by using spinnerets with cross flow outside the spinneret. As a specific example, the measurement is made through spinnerets having 34 bonded orifices as specifically described above at a temperature of 290 ° C. of a molten polyester polymer of conventional molecular weight. The amount of polymer produced is controlled to produce an average of 4 denier filaments per filament at a spinning speed of 5,200 inches / minute, with the melt flow being quenched by quenching air flowing in the normal transverse direction.

Under these spinning conditions, a surprising phenomenon occurs as shown in FIG. Because of the geometry of the spinneret, the speed of the polymer flowing through the small capillary 30 is much faster than the polymer flowing through the large capillary. The speed and angle of the pair of streams coming from each associated orifice, the angle at which the streams are connected outside the spinneret, are defined between the successive adhesion points 38 with each of the small and fast streams 36 being large. While forming a circular line back and forth, the slow stream actually moves in a straight line just after the pair of streams first touch and bond.

This action can be easily observed by using a stroboscopic beam directly in the stream directly below the spinneret 28. As the melt flow accelerates away from the spinneret, the slower flow becomes thinner between the bond points 38, and the faster flow annular line is straightened until the faster flow is in continuous contact with the slower flow. do. Slower streams become thinner between these bond points than at the first point of attachment, resulting in a larger cross section than the portion between their bond points at the first point of attachment. The composite flow obtained becomes thinner to some extent until the transverse direction is entrained into their filaments 40 by quenching air.

Each solidified filament 40 has a non-round cross-sectional area that varies repeatedly in the longitudinal direction.

As shown qualitatively in FIG. 6, when the above spinning conditions are used, the filament cross-sectional area is repeatedly changed at a repetition speed of about 1 m. However, this can be varied by modifying the radiation conditions and the geometry of the spinneret passages.

Due to the slight differences between the combined orifices, the spinneret temperature change, and the same shape variations from each other in exactly the same treatment for each pair of streams, the multiple orifice spinneret typically differs between several obtained streams and filaments. Give a repeat speed. One example of this is qualitatively shown in FIG. 7, which shows that various orifices produce somewhat different repetition rates when measured by stronomically a complex flow just below the spinneret. In the obtained multifilament yarns, the filaments have a non-round cross section that varies by more than ± 10% depending on the length of the filament, and the variation of the cross-sectional area is outside from the phase between the filaments. The yarn gets twisted by heating.

Multifilament yarns have a variety of applications and uses. When woven into a fabric, this fabric has a new effect by directing it to a fabric comprising yarns spun from staple fibers in this respect. Other new effects can be easily obtained by changing the spinneret and the spinning conditions small.

For some of these effects, it is preferable that the cross-sectional area of the filament fluctuate repeatedly in the longitudinal direction by ± 25% or more (preferably ± 30% or more). This effect is particularly emphasized when the yarn has a Worcester heterogeneity of at least 2.5% u. The measurement of Worcester is carried out using the Uster Evenness Tester Models in conjunction with the integrator ITG-101 for this device. The firing speed is 182.8 meters per minute (200 ypm), fixed at the service selector or standard, and the sensitivity selector at 12,5%. u% is read from the Interceptor after the sample has been tested for 5 minutes.

Shrinkage is measured according to the method described below. Generally speaking, measure the initial length (L ₀ ) of the sample yarn while the yarn is under tension of 0/1 g / denier. The yarn is then subjected to a tension of 0.0025 g / denier and then placed in an oven at 120 ° C. for 5 minutes. Next, the yarn is taken out of the oven and subjected to tension of 0.1 g / denier again to measure the length (L ₀ ). Shrinkage (%) is as follows.

Claims (1)

A pair of fibrous, molecular weight molten polymers running at different speeds are generated to focus at a point below the surface of the spinneret, wherein the velocity of the stream and the angle of focusing the stream are slower than the first of the stream Selects to move almost linearly after the first contact, and to form a curved loop back and forth between successive points in combination with the first one of the above class; Straightening the curved loop by elongating the first of the stream so that the second of the stream is in continuous contact with the first of the stream; And a composite denier filament obtained by quenching the obtained composites to form a filament.

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