JPH0366409B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyester processed yarn having untwisted parts and overtwisted parts alternately along the longitudinal direction of the yarn, and more specifically, untwisted parts and overtwisted parts obtained by performing an unsteady false twisting operation. The present invention relates to a polyester processed yarn having a yarn having untwisted portions alternately along the longitudinal direction, having a high initial modulus of elasticity, and having a small degree of cross-sectional deformation of a single filament. In recent years, fabrics made from polyester threads have become extremely important for clothing, especially for inner and outer clothing, because they have excellent features such as wash-and-wear properties and wrinkle resistance. However, when polyester yarn is processed into a fabric as it is, it has a high initial elastic modulus, so it has excellent firmness and stiffness, but on the other hand, the surface is smooth and there is little change in appearance, and it has a slimy feel and texture. The disadvantage is that it is bad. In order to eliminate the above-mentioned drawbacks due to the use of raw yarn, the proportion of fabricated yarns that are crimped and that use false-twisted yarn has increased significantly. Since the initial elastic modulus is significantly lower than that of polyester fibers, it is not possible to effectively realize the excellent characteristics of polyester fibers such as firmness and stiffness, and although it has bulkiness due to crimping, it is difficult to achieve uniform bulkiness. Therefore, the change in appearance was not sufficient. Furthermore, as consumer demands for fibers have diversified, many yarns have been proposed that have irregularly shaped cross sections to give them special luster, such as silk-like luster. Even if it had luster, the cross section was deformed during the false twisting process, so it was not possible to fully exhibit the desired luster as a textured yarn. The present invention has been made in view of the above points, and its purpose is to provide not only a natural appearance by the twist patterns of the untwisted part and the vortex-untwisted part, but also firmness. To provide a processed polyester yarn that has a firm waist and does not feel slimy, and does not impair the luster of the raw yarn. The above purpose is to provide untwisted portions and tentatively twisted portions having only twists in the direction of false twisting, which are obtained by subjecting a polyester multifilament yarn to an active unsteady false twisting operation in which it is twisted intermittently in the S or Z direction. A yarn that alternately has over-untwisted parts that are only twisted in the twisting/untwisting direction, where the untwisted parts and over-untwisted parts are both 50 cm or more in length, and the following (1) , (2) is achieved by a polyester processed yarn that is characterized in that it simultaneously satisfies formula (2). A>40 (1) 33<A/B<A (2) However, A: Initial modulus of elasticity (g/d) B: Cross-sectional deformation of single filament The present invention will be explained in detail below based on the attached drawings. . The processed polyester yarn of the present invention is a yarn obtained by subjecting a polyester multifilament yarn to an active unsteady false twisting operation in which it is twisted intermittently in the S or Z direction, and the yarn is twisted as shown in FIG. Along the longitudinal direction of the strip, untwisted portions 1 having only twists in the false-twisting direction and over-twisted portions 2 having only twists in the false-twisting and untwisting direction coexist alternately. Non-twisted portions 3 and 4 are formed between the over-untwisted portion 1 and the over-untwisted portion 2, and between the over-untwisted portion 2 and the untwisted portion 1, respectively. As will be described later, the untwisted portion 1 is a yarn portion with poor bulkiness in which the supplied yarn is bundled because the twisting by the false twisting body remains sufficiently heat-fixed, and on the other hand, The over-twisted part 2 is a state in which the twisted yarn is heat-set and then untwisted beyond the zero point of the twist number in the opposite direction, so the yarn has more bulk than the untwisted part 1. This is the strip part. Since untwisted parts 1 and overtwisted parts 2 having different bulkiness exist alternately along the longitudinal direction of the yarn, untwisted parts 1 and overtwisted parts 2 that exist between untwisted parts 1 and overuntwisted parts 2 Together with parts 3 and 4, it is possible to give the yarn a natural appearance unevenness. Further, in the yarn of the present invention, the untwisted portion and the untwisted portion are as described above.
Since it satisfies formulas (1) and (2) at the same time, it has the advantage of having firmness and firmness without feeling slimy, and furthermore, does not impair the luster of the yarn. That is, FIG. 4 is an example of the overload elongation curve of the polyester yarn a, the untwisted part b ₁ and over-untwisted part b ₂ of the yarn of the present invention obtained from the raw yarn, and the normal false twisted yarn c. The initial elastic modulus of normal false twisted yarn is about 35 g/d, which is small compared to the initial elastic modulus of polyester yarn, whereas the initial elastic modulus of the yarn of the present invention is about 35 g/d, which is small compared to the initial elastic modulus of polyester yarn. Since both exceed 40 g/d, it is possible to maintain the firmness, waist, and drape properties of the polyester yarn due to its high initial elastic modulus. In addition, although polyester yarn has a slimy feel, the yarn of the present invention does not have a slimy feeling and has a moderate silkiness due to the actual twist remaining in the untwisted portion and the over-twisted portion. In order to give the yarn firmness and stiffness comparable to that of raw yarn, it is preferable that the initial elastic modulus A is large. The initial elastic modulus A is especially 40 to 60, as the number of twists decreases, causing a slimy feeling and the natural appearance caused by uneven twisting becoming more likely to be lost.
A range of g/d is preferred. Furthermore, since false twisted yarn is usually heat set in a close-packed state during twisting, the cross section of the single filament is deformed, for example, in the case of a circular cross section yarn, it deforms into a polygonal shape as shown in Figure 3. The gloss will be lost.
However, in the yarn of the present invention, the relationship between the degree of cross-sectional deformation B and the initial elastic modulus A of the single filament satisfies the relationship 33<A/B<A, so the untwisted portion and the over-untwisted portion shown in FIG. The degree of cross-sectional deformation of the single filament in both parts is small, so the luster of the yarn is not impaired. In recent years, many polyester yarns have been proposed in which the cross section of a single filament is made into various shapes such as polygonal or multilobal to give the yarn a special luster for silk-like luster. It is particularly effective when such irregular cross-section yarn is used as the supplied yarn, since it does not cause any damage. As mentioned above, in order not to damage the luster of the yarn
33<A/B<A Preferably, it is necessary to satisfy the relationship 35<A/B<A, and if 33≧A/B, the initial elastic modulus is too small or/and the cross section of the single filament is Since the degree of deformation is too large, the luster, firmness, and elasticity of the yarn are impaired, which is not desirable. On the other hand, in the case of A/B=A, the single filament is not deformed at all, so the number of remaining twists in untwisted and overly twisted areas is extremely small, and the natural appearance due to uneven twisting is lost. This is not preferable because it gives a slimy feeling. In addition, in the yarn of the present invention, there are untwisted parts between the untwisted part and the overly untwisted part and between the overly untwisted part and the untwisted part, but neither of the untwisted parts (1) above,
Since it satisfies formula (2), it has firmness and elasticity without feeling slimy, and does not impair the advantage of retaining the luster of the yarn. In addition, when measuring the initial elastic modulus centering on the boundary between a non-twisted part and an untwisted part or a non-twisted part and an over-untwisted part, or a sample containing a non-twisted part, an untwisted part and an over-untwisted part, When measuring with a fabric, the initial elastic modulus may fall below 40 g/d due to the propagation of twist, but since the non-twisted part is short, if it is made into a fabric, it will be restrained by the tissue and the propagation of twist will be prevented. The above effects can be maintained. Therefore, the measurement of the initial elastic modulus described below was carried out separately for the untwisted part and the over-untwisted part, and for the untwisted part, the untwisted part and the over-untwisted part were included. Measure with a sample. The initial elastic modulus A as used in the present invention was determined by converting the stress value corresponding to 100% elongation into per denier from the inclination angle of the rising portion of the load elongation curve (average value of 5 measurements). Furthermore, when the cross section of the yarn of the present invention is approximately circular, the degree of cross-sectional deformation B of the single filament is determined by the line segment bisecting the cross section perpendicular to the diameter of the circumscribed circle
It is the average value of the diameter of the circumscribed circle divided by the shortest line segment, and on the other hand, in the case of irregular cross-section yarn, the ratio of the diameter of the circumscribed circle and the circumscribed circle is calculated for the yarn of the present invention and the supplied raw yarn, This is the value obtained by dividing the larger ratio by the smaller ratio, and in each case, measurements were taken on five arbitrary single filaments, and the average value was used. Next, an example of the manufacturing method of the present invention will be explained. First, the polyester multifilament yarn is passed through an unsteady false-twisting zone consisting of a heater and a false-twisting nozzle (hereinafter simply referred to as a nozzle) that intermittently supplies fluid, and by intermittently supplying liquid to the nozzle. The yarn is repeatedly turned in one direction and then stopped, giving the yarn an alternating twist that utilizes the transient phenomenon of false twisting.
In this case, when fluid is first supplied to the nozzle, the twists twisted in the twisting zone before passing through the nozzle are heat-set by the heater, and then when the fluid supply is stopped, the twists heat-set in the twisting zone are In the untwisting zone after passing through the nozzle, the untwisted portion passes through without being subjected to the untwisting action, and the untwisted portion having a twist in the false twisting direction is pulled out. When the liquid stops, the twisting of the yarn passing through the untwisting zone decreases, but when the fluid supply is restarted, the untwisting action occurs rapidly in the untwisting zone, causing the false twisting and untwisting to occur. The over-twisted part with twist in the direction is pulled out, and the untwisted part is pulled out in the section from the untwisted part to the over-untwisted part and the section from the over-untwisted part to the untwisted part, and if necessary, It is reheated and rolled up into a package. The yarn of the present invention is basically obtained by the active unsteady false-twisting operation as described above, but in addition, the yarn can be used as a yarn supply roller to the unsteady false-twisting zone in conjunction with the supply and stop of liquid to the nozzle. By using a roller with a variable speed function or by using a passive yarn supply device that rotates depending on the running tension of the yarn, the yarn overfeed rate when liquid is supplied to the nozzle can be adjusted to the overfeed rate when the liquid is stopped. greater than the rate;
And adjust the heater temperature, fluid pressure, and flow rate to reduce the number of remaining twists in the untwisted part from 4900/√D to 12200/√D (T/M)
, the number of remaining twists in the over-twisted part is 2300/√D ~ 7700/√D (T/M) (
However, by setting D in the range of the denyl number of the supplied yarn, the initial elastic modulus and the degree of cross-sectional deformation of the single filament can simultaneously satisfy equations (1) and (2). Further, even when using a constant speed yarn supply roller, the yarn of the present invention can be obtained by appropriately adjusting the heater temperature, fluid pressure, flow rate, etc. Further, the over-untwisted portion of the processed yarn of the present invention is formed when the nozzle is pressurized, and the untwisted portion is formed when the nozzle is stopped. In Example 1, which will be described later, the delivery roller speed is 80 m/min, so the speed per second is
It is 1.33mm. In Example 1, the nozzle pressure supply time and nozzle stop time are both 0.5 seconds, so the length of 67 cm
As is clear from the over-untwisted degree and the formation of untwisted parts, the processed yarn of the present invention has a length of both the untwisted part and the over-untwisted part of 50 cm or more, and the length of the untwisted part is 50 cm or more. There are few In the present invention, polyester is a polymer having an ester bond in its molecular chain, and includes homopolymers typified by polyethylene terephthalate, copolymers or blend polymers thereof, and one of these threads One or more yarns can be used as supply yarns. In addition, the false-twisting bodies used in the unsteady false-twisting process include the above-mentioned false-twisting nozzle using compressed fluid and spindle-type twisting bodies driven by a belt, as well as friction-type twisting bodies and air spindles. A type twisted body etc. can be used. Hereinafter, the present invention will be specifically explained with reference to Examples. Example 1 Polyester filament 150d/72f (circular cross-sectional shape, semi-dull yarn, initial elastic modulus 94 g/d) was supplied to a processing process consisting of a variable-speed supply roller, a heater, a false-twisting nozzle, and a delivery roller, and was false-twisted. An unsteady false twisting process was performed in which intermittent twisting was performed in one direction using a nozzle to obtain a textured yarn in which untwisted portions and overly twisted portions alternated in the longitudinal direction of the yarn. Table 1 shows the processing conditions.

【table】 Table 2 shows the properties of the processed yarn obtained.

【table】

[Table] Using the obtained processed yarn, the fabric was made into a plain weave structure with a warp density of 80 threads/inch and a weft density of 68 threads/inch, which has natural appearance unevenness due to twist irregularities in untwisted parts and over-twisted parts. It also had firmness, firmness, and no slimy feeling, and furthermore, it retained the luster of the supplied yarn. The number of remaining twists is calculated by applying a tension of 2 mg/d to the yarn, and testing the twist at 5 cm intervals over the entire length of each untwisted section and over-untwisted section at 5 points each. The number of twists was defined as the number of unraveled twists or the number of twists in the over-twisted portion (converted to T/M).

[Brief explanation of drawings]

Fig. 1 is a schematic side view of the processed polyester yarn of the present invention, Fig. 2 is a sectional view of the untwisted portion of the same as above, Fig. 3 is a sectional view of the normal false twisted yarn, and Fig. 4 is the polyester raw yarn a and this Untwisted portion of the yarn of the present invention obtained from the raw yarn
It is a graph of overload elongation curves of b ₁ and over-untwisted portion b ₂ and normal false twisted yarn c. In the figure, 1 is an untwisted part, and 2 is an over-twisted part.

Claims (1)

[Claims] 1. Untwisted polyester multifilament yarn having only twists in the false-twisting direction, obtained by subjecting polyester multifilament yarn to an active unsteady false-twisting operation in which it is twisted intermittently in the S or Z direction. A yarn having alternating sections and over-untwisted sections having twists only in the false-twisting/untwisting direction, in which the lengths of both the ununtwisted section and the over-untwisted section are 50 cm or more, and the following: A processed polyester yarn characterized by satisfying formulas (1) and (2) at the same time. A>40...(1) 33<A/B<A...(2) However, A: Initial elastic modulus (g/d) B: Cross-sectional deformation of single filament