Temporarily twisted yarn

Abstract

To provide a false twisted yarn by which textile having sufficient tensive and stiff feeling and linen-like feeling can be obtained.SOLUTION: A false twisted yarn is made of polyester filaments and has non-untwisted sections and untwisted sections alternately existing in a yarn longitudinal direction. The false twisted yarn has 40 to 110 non-untwisted sections having lengths of 0.3 to 12 mm in the yarn longitudinal direction per 1 m yarn. A ratio of lengths in a yarn width direction of the non-untwisted sections to the untwisted sections (non-untwisted sections / untwisted sections) is 1 / 2 to 1 / 14. Furthermore, non-untwisted sections A having lengths less than 0.3 to 3 mm and non-untwisted sections B having lengths of 3 to 12 mm are provided as the non-untwisted sections. The false twisted yarn has 30 to 85 non-untwisted sections A per 1 m yarn and 3 to 25 non-untwisted sections B per 1 m yarn.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a polyester filament, which is a false-twisted yarn having an untwisted portion and a twisted portion in the longitudinal direction of the yarn.

Background Art

[0002] Conventionally, as a processing method for imparting a hemp-like special texture using a polyester multifilament, a method is well-known in which the polyester multifilament is subjected to false-twisting in a fused high-temperature region to partially fuse the single fibers to each other and at the same time to generate an untwisted portion. That is, such a processed yarn has a structure in which the multifilament heated during false-twisting is partially fused, and an untwisted portion fused and fixed in the same direction as the twist direction and a twisted portion untwisted in the direction opposite to the twist direction are alternately present in the longitudinal direction of the yarn.

[0003] Patent Document 1 proposes a fused draw false-twisted yarn capable of forming a fabric having a texture similar to that of a real-twisted yarn or a light kasuri pattern by having the length and number of untwisted portions in the yarn be equal to or greater than a certain quantity.

[0004] Further, Patent Document 2 proposes a fused false-twisted yarn capable of producing a knitted fabric with a rich expression by shortening the untwisted length of the fused draw false-twisted yarn.

[0005] These false-twisted yarns have an untwisted portion and a twisted portion, but the entire yarn after false-twisting has a substantially uniform thickness, and the visual change is only a small amount. Therefore, there is a problem that it is difficult to say that a good texture is produced throughout the yarn. Therefore, in Patent Document 3, a false-twisted yarn is proposed that includes a thin untwisted portion in which a part of the raw yarn is heat-treated to fuse and hold the twist during twisting, and a thick over-twisted portion in which the other part of the raw yarn is excessively twisted to have a bulge.

[0006] However, in any of the false-twisted yarns, it has not been possible to obtain a woven fabric having sufficient stiffness and a linen-like texture by weaving.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0008] The present invention solves the above problems, and it is a technical problem to provide a false-twisted yarn capable of obtaining a woven fabric having sufficient stiffness and a linen-like texture.

Means for Solving the Problems

[0009] The inventors of the present invention conducted intensive studies to solve the above problems, and as a result, found that by setting the lengths in the longitudinal direction, the lengths in the width direction, and the number of the untwisted portions and the twisted portions in the longitudinal direction of the yarn to those within a specific range, the above problems can be solved, and thus the present invention was achieved.

[0010] That is, the present invention has the following gist. (1) A false-twisted yarn made of polyester filaments, in which untwisted portions and twisted portions are alternately present in the longitudinal direction of the yarn, having 40 to 110 untwisted portions with a length of 0.3 to 12 mm in the longitudinal direction of the yarn per 1 m of the yarn, and the ratio of the length in the width direction of the yarn of the untwisted portion to the twisted portion (untwisted portion / twisted portion) is 1 / 3 ~1 / 14 false-twisted yarn. (2) As the untwisted part, it has an untwisted part A with a length of less than 0.3 to 3 mm and an untwisted part B with a length of 3 to 12 mm. There are 30 to 85 untwisted parts A per 1 m of the yarn, and 3 to 25 untwisted parts B per 1 m of the yarn. The false-twisted yarn according to (1). (3) The ratio of the total length of the untwisted parts per 1 m of the yarn to the total length of the untwisted parts per 1 m of the yarn is such that the total length of the untwisted parts / the total length of the untwisted parts = 1 / 3 to 1 / 10. The false-twisted yarn according to (1) or (2). (4) The single fiber constituting the false-twisted yarn has a single fiber fineness of 5 to 20 dtex and a multi-leaf shape having 3 to 8 convex portions in a cross-section perpendicular to the fiber longitudinal direction. The false-twisted yarn according to any one of (1) to (3).

Advantages of the Invention

[0011] In the false-twisted yarn of the present invention, untwisted parts and untwisted parts alternately exist in the longitudinal direction of the yarn. Since the lengths in the longitudinal direction of the yarn, the lengths in the width direction, and the numbers of the untwisted parts and the untwisted parts satisfy specific ranges, it is possible to obtain a fabric with sufficient stiffness, a hemp-like texture, and excellent dyeability by weaving.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0013] Hereinafter, the false-twisted yarn of the present invention will be described with reference to the drawings. FIG. 1 is a partially enlarged view of the false-twisted yarn of the present invention. FIG. 1(a) is an enlarged view of the untwisted part 1, and FIG. 1(b) is an enlarged view of the untwisted part 2. The false-twist textured yarn of the present invention is obtained by subjecting a raw yarn, which is a highly oriented undrawn yarn or a drawn yarn, to false-twist processing, whereby an untwisted portion 1 and a twisted portion 2 are alternately formed in the longitudinal direction of the yarn. The untwisted portion 1 is formed by heating and melting a part of the raw yarn while it is being twisted at a high temperature, and the single fibers constituting the raw yarn are fused to each other, and it retains the twist in the twisted state. The twisted portion 2 is formed by over-twisting the unfused portion of the raw yarn during false-twist processing, and has a large bulge due to the increase in the distance between the single fibers.

[0014] The above-mentioned untwisted portion 1 and twisted portion 2 exist alternately in the longitudinal direction of the yarn. The length of the untwisted portion 1 in the longitudinal direction of the yarn is 0.3 to 12 mm, and the number of untwisted portions 1 per 1 m of the yarn is 40 to 110 pieces / m. If the number of untwisted portions 1 is less than 40 pieces / m or exceeds 110 pieces / m, the resulting fabric will lack stiffness and a linen-like texture (crispness). Among them, in order to obtain a fabric excellent in such stiffness and linen-like texture, the false-twist textured yarn of the present invention preferably has, as the untwisted portion 1, 35 to 85 untwisted portions A having a length of less than 0.3 to 3 mm and 5 to 25 untwisted portions B having a length of 3 to 12 mm per 1 m of the yarn.

[0015] And the ratio of the total length of the untwisted portion 1 per 1 m of the yarn to the total length of the twisted portion 2 per 1 m of the yarn is preferably untwisted portion total length / twisted portion total length = 1 / 3 to 1 / 10, and more preferably 1 / 4 to 1 / 8.

[0016] Furthermore, the false-twist textured yarn of the present invention preferably has a ratio of the length in the width direction of the yarn of the untwisted portion to the twisted portion (untwisted portion / twisted portion) of 1 / 2 to 1 / 14, and more preferably 1 / 3 to 1 / 12.

[0017] As described above, the false-twisted yarn of the present invention has the ratio of the length in the yarn longitudinal direction and the length in the width direction of the untwisted portion where the single fibers are fused together and the untwisted portion where the single fibers are not fused together within the above range. As a result, the appearance of the entire yarn becomes complex and rich in variation, and it is possible to exhibit a hemp-like texture and a feeling of stiffness when made into a fabric. Therefore, when the ratio of these lengths is outside the above range, the resulting fabric will lack a hemp-like texture and a feeling of stiffness.

[0018] The length in the yarn longitudinal direction and the number of the untwisted portions in the false-twisted yarn, and the length in the yarn width direction of the untwisted portions and the twisted portions are measured as follows. Apply an initial load of 0.0882 cN / dtex to the false-twisted yarn and mark it at the 1 m position. Next, measure the length of the untwisted portion using an optical microscope (Keyence Corporation's "Microscope VHX-900") under a light load of 0.00882 cN / dtex, and divide the untwisted portions into untwisted portions A with a length of less than 0.3 to 3 mm and untwisted portions B with a length of 3 to 12 mm per 1 m of the yarn and determine the number. At this time, also measure the yarn widths of the untwisted portions and the twisted portions. Measure with N = 5 and calculate the average value. Note that the yarn widths of the untwisted portions and the twisted portions are measured by visually observing the portion with the maximum yarn width.

[0019] The false-twisted yarn of the present invention is composed of polyester filaments. The polyester filaments may be composed of any polyester typified by polyalkylene terephthalate. Specifically, polyethylene terephthalate (PET), polybutylene terephthalate, polytrimethylene terephthalate, etc. may be mentioned. Further, in view of viscosity, thermal properties, compatibility, etc., aromatic dicarboxylic acids such as isophthalic acid and 5-sulfoisophthalic acid, aliphatic dicarboxylic acids such as adipic acid, succinic acid, suberic acid, sebacic acid, dodecanedioic acid, and aliphatic diols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, and hydroxycarboxylic acids such as glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, hydroxypentanoic acid, hydroxyheptanoic acid, hydroxyoctanoic acid, and aliphatic lactones such as ε-caprolactone may be copolymerized.

[0020] Further, antistatic agents, antibacterial agents, deodorants, etc. for imparting functionality may be added to the above polyester filaments.

[0021] And the single fibers constituting the false-twisted yarn of the present invention preferably have a single fiber fineness of 5 to 20 dtex, and more preferably 8 to 18 dtex. Further, these single fibers preferably have a multi-lobed shape having 3 to 8 convex portions in a cross section perpendicular to the fiber longitudinal direction, and more preferably a cross-shaped cross section having 4 convex portions. Thus, since the single fiber fineness of the single fibers constituting the false-twisted yarn is relatively large and has a cross-sectional shape having convex portions, the appearance of the entire yarn becomes complex and rich in variation.

[0022] That is, during false twisting, the intertwined parts where the convex portions of each single fiber are intertwined like gears and do not easily separate become the non-untwisted parts, and the length in the yarn width direction becomes small. On the other hand, the parts where the convex portions of each single fiber do not intertwine become the untwisted parts. Since they exist without being intertwined, they are bulky due to the convex shape of each single fiber and have a large bulge, and the length in the yarn width direction becomes large.

[0023] Also, the total fineness of the false-twisted yarn of the present invention is preferably 90 to 200 dtex, and more preferably 100 to 180 dtex.

[0024] Furthermore, the crimp ratio of the false-twisted yarn of the present invention is preferably 20 to 60%, and more preferably 30 to 50%. By setting the crimp ratio in this way, there is no puffiness when made into a fabric and it does not become too soft. By balancing and fusing the non-untwisted part and the untwisted part, a fabric with good crispness and stiffness can be obtained.

[0025] The above crimp ratio is measured as follows. After taking a sample of the false-twisted yarn by winding it 5 times using a measuring machine with a frame circumference of 1.125 m, the sample is hung on a stand in a free state at room temperature for one day and one night. Next, while applying a load of 0.000147 cN / dtex to the sample, it is immersed in boiling water and subjected to a wet heat treatment for 30 minutes. Then, the sample is taken out, the moisture is gently removed with filter paper, and it is left in a free state at room temperature for 30 minutes. Then, a load of 0.000147 cN / dtex and a load of 0.00177 cN / dex (light and heavy load) are applied to the sample, and the length X is measured. Subsequently, while the load of 0.000147 cN / dtex is still applied, instead of the light and heavy load, a load of 0.044 cN / dtex (heavy load) is applied, and the length Y is measured. Then, the crimp ratio is calculated by the following formula. Crimp ratio (%) = (Y - X) / Y × 100 The measurement of the crimp ratio is carried out with N = 5, and the average is taken as the crimp ratio.

[0026] In addition, the false-twisted yarn of the present invention preferably has a torque of 90 to 140 T / M, and more preferably 100 to 130 T / M. By setting the torque within this range, excessive entanglement does not occur in the false-twisted yarn. When forming a fabric, the occurrence of pills and creases can be suppressed during the process passage, and troubles do not occur, and a high-quality fabric can be obtained with good operability. And, the false-twisted yarn of the present invention preferably has a Z twist.

[0027] The above torque is measured as follows. A load of 0.0294 (cN / dtex) is applied to the false-twisted yarn so that it does not rotate, and a sample length of 200 cm is collected. Next, the distance between both ends of the collected sample is set to 2 cm and held almost parallel, and a load of 0.00294 (cN / dtex) is applied to the center part (at 100 cm) to form a V shape, and the lower part of the V shape is made in a tension-free state. At this time, rotation due to the residual torque of the sample occurs, and it is left until the rotation stops. After the rotation stops, the number of rotations is measured with a twist tester, and the value obtained by this measurement is taken as the torque number.

[0028] Next, the manufacturing method of the false-twisted yarn of the present invention will be described with reference to FIG. 2. The false-twisted yarn of the present invention is obtained by subjecting a polyester filament to false-twisting. As the filament to be subjected to false-twisting, after melt-spinning a polyester raw polymer, a drawn yarn (FDY) subjected to drawing and heat treatment, or a partially oriented undrawn yarn (POY) wound at a speed of preferably 2000 m / min to 3500 m / min after melt-spinning is preferably used.

[0029] In the present invention, as the drawn yarn (FDY), those having an elongation of 20 to 40% are preferred, and as the partially oriented undrawn yarn (POY), those having an elongation of 80 to 110% are preferred.

[0030] The false-twisting is performed by a heat treatment heater 2 and a false-twist imparting device 3 provided between the supply roller 1 and the first take-up roller 4. When using drawn yarn as the filament for false-twisting, the drawing ratio is 0.90 to 1.20 times, preferably 0.95 to 1.10 times. When using highly oriented undrawn yarn, the drawing ratio is 1.10 to 1.70 times, preferably 1.20 to 1.50 times. When using drawn yarn, it is also preferable to perform false-twisting with a false-twist overfeed rate of 1.8 to 5.0% without drawing.

[0031] Note that the drawing ratio and the false-twist overfeed rate are adjusted by the difference in the roller speeds of the supply roller 1 and the first take-up roller 4. When the speed of the first take-up roller 4 is faster than that of the supply roller 1, it results in drawing, and when the speed of the first take-up roller 4 is slower than that of the supply roller 1, it results in overfeed. The overfeed rate is a value calculated by the following formula, where the yarn speed immediately before being introduced into the false-twist applying device 3 is V1 and the yarn speed immediately after passing through the false-twist applying device 3 is V2. That is, in Fig. 2, the yarn speed V1 is the speed of the supply roller 1, and the yarn speed V2 is the speed of the first take-up roller 4. Overfeed rate (%) = {(V1 - V2) / V2} × 100

[0032] And it is preferable to perform false-twisting under the conditions of a false-twist number of 2000 to 5000 T / M, preferably 2200 to 4000 T / M, and the temperature of the heat treatment heater 2 (false-twist temperature) of 150 to 240°C, preferably 170 to 230°C. The K value (untwisting tension / twisting tension) is preferably 1.5 to 3.0.

[0033] To form an untwisted part where the single fiber yarns of the raw yarn are fused together in the obtained false-twisted yarn, it is preferable that the temperature of the heat treatment heater is equal to or higher than the softening point and lower than the melting point of the polyester filament that becomes the raw yarn. By adjusting the temperature of the heat treatment heater, an untwisted part and an untwisted part are formed in the longitudinal direction of the yarn, and their lengths and widths can be adjusted.

[0034] Examples of the false-twist applying device used for false-twisting include pins, friction disks, belts, etc., among which the pin type is preferable.

[0035] Then, the false-twisted yarn that has been false-twisted by the heat treatment heater 2 and the false-twist imparting device 3 provided between the supply roller 1 and the first take-up roller 4 is taken up through the take-up roller 5 to obtain a package 6 of the false-twisted yarn.

[0036] When obtaining a woven fabric using the false-twisted yarn of the present invention obtained as described above, it is preferable to further perform over-twisting and then supply it to the weaving process. When the false-twisted yarn has a Z twist, the over-twisting is preferably 200 to 400 T / M with an S twist.

[0037] As a woven fabric using the false-twisted yarn of the present invention, the false-twisted yarn of the present invention can be used for either or both of the warp and weft yarns, but it is preferably used for the warp yarn. Among them, as the one preferably used for the weft yarn, a blended spun yarn (20 to 50 counts) of polyester fiber and cotton is particularly mentioned. Such a weft yarn has softness and hygroscopicity, and when combined with the hemp-like texture and sufficient stiffness of the warp yarn, it becomes a comfortable woven fabric. etc. are mentioned.

[0038] And the weave of the obtained woven fabric is not particularly limited, and examples include plain weave, twill weave, damask weave, etc., and it may be a multi-layer weave as required. Among them, plain weave is preferable. Also, the cover factor (CF) is not particularly limited, but it is preferably 1500 to 2600. The cover factor (CF) is a numerical value representing the coarseness and density of woven and knitted fabrics, and is calculated by the following formula. Here, in the formula, D represents the total fineness of the warp yarn. E represents the total fineness of the weft yarn. CF = D 1 / 2 × warp density (ends / 2.54 cm) + E 1 / 2 × weft density (ends / 2.54 cm)

Examples

[0039] Hereinafter, the present invention will be described in more detail according to examples. The measurement methods and evaluation methods of various characteristic values in the examples are shown. (1) Length, number of untwisted parts, and widthwise length of untwisted and twisted parts in the longitudinal direction of the yarn Measured by the method described above. (2) Single fiber fineness, total fineness Measured based on JIS L1013 8.3.1. (3) Crimp ratio, torque Measured by the method described above.

[0040] (4) Fabric evaluation The stiffness and crispness of the obtained fabric (dyeing reaction) were evaluated in four grades by touch, and the quality during dyeing was evaluated visually according to the following criteria. <Stiffness>[[]] ◎: Very good ○: Good △: Normal ×: Bad <Crispness (linen touch like hemp)>[[]] ◎: Very good ○: Good △: Normal ×: Bad <Quality during dyeing (hemp-like texture)>[[]] ◎: Very good ○: Good △: Normal ×: Bad

[0041] Example 1 As the supply yarn, a drawn polyester yarn (109 dtex / 10 filaments) with an elongation of 34%, a single fiber fineness of 10.9 dtex, and a four-lobed cross-sectional shape of the single fiber was used. Then, according to the process shown in Figure 2, false twisting was performed to obtain false-twisted yarn. At this time, as the false-twisting device 3, a spindle pin type device was used, and false twisting was performed under the conditions of a processing speed (first roller speed) of 113.2 m / min, a false-twisting temperature (heat treatment heater temperature) of 220°C, a false-twisting overfeed rate of 3.92%, a false-twisting number of S twist, 2557 T / M, and a K value of 2. The twisting tension was measured between the heat treatment heater 2 and the false-twisting device 3, and the untwisting tension was measured between the false-twisting device 3 and the first take-up roller 4.

[0042] The obtained false-twisted yarn (117 dtex / 10 filaments) was a crimped yarn having an untwisted part and a twisted part (crimp rate 38.7%), and the lengths, widths, and numbers of the untwisted part and the twisted part were as shown in Table 1. This false-twisted yarn was over-twisted (S-300 T / M) and used as a warp yarn. For the weft yarn, a blended spun yarn of 30s polyester fiber and cotton yarn was used, and a plain fabric was woven with a warp density of 84 ends / 2.54 cm and a weft density of 66 picks / 2.54 cm.

[0043] The obtained fabric was scoured at 80 °C for 20 minutes with 2 g / l of a non-ionic surfactant (Sunmorl FL manufactured by Nikka Chemical Co., Ltd.) and subjected to a preset treatment at 180 °C for 30 minutes. Next, under the following dyeing conditions, a dyeing treatment was carried out, and a finishing set was performed at 170 °C to obtain a fabric with a warp density of 87 ends / 2.54 cm, a weft density of 87 picks / 2.54 cm, and a cover factor of 1698. The obtained fabric was extremely excellent in stiffness and crispness, and also had an extremely excellent dyed quality with a linen-like feeling. (Dyeing conditions) · Dye: Dianix Blue UN-SE (manufactured by Dianix Co., Ltd.) 1% o.m.f · Auxiliary agent: Nikkasalt SN-130 (manufactured by Nikka Chemical Co., Ltd.) 0.5 g / L : Acetic acid 0.2 cc / L · Temperature × Time: 130 °C × 30 minutes · Bath ratio: 1:30

[0044] Example 2 As the supply yarn, a polyester high-oriented undrawn yarn (178 dtex / 10 filaments) with an elongation of 94%, a single fiber fineness of 17.8 dtex, and a yarn cross-sectional shape of four-lobed was used. Then, according to the process shown in Figure 2, a false-twisting process was performed to obtain a false-twisted yarn. At this time, stretching was performed during false-twisting, and it was carried out in the same manner as in Example 1 except that the false-twisting processing conditions were changed to those shown in Table 1. The characteristic values of the obtained false-twisted yarn are shown in Table 1. Then, using the obtained false-twisted yarn, a plain fabric was woven in the same manner as in Example 1 except that the warp density and the weft density were changed to those shown in Table 1. Subsequently, the obtained plain woven fabric was subjected to scouring and dyeing in the same manner as in Example 1 to obtain a woven fabric. The obtained woven fabric had extremely excellent stiffness and crispness, and also had extremely excellent dyed quality with a linen-like texture.

[0045] Example 3 Using the same supply yarn as in Example 1, false twisting was performed in the same manner as in Example 1, except that the false twist overfeed rate was changed to 2%. The characteristic values of the obtained false-twisted yarn are shown in Table 1. Then, using the obtained false-twisted yarn, weaving was performed in the same manner as in Example 1, except that the warp density and weft density were changed to those shown in Table 1, to obtain a plain woven fabric. Subsequently, the obtained plain woven fabric was subjected to scouring and dyeing in the same manner as in Example 1 to obtain a woven fabric. Since the number of untwisted parts A and B in the obtained false-twisted yarn was less than the preferable range, the woven fabric obtained using this false-twisted yarn had good stiffness, crispness, and dyed quality.

[0046] Example 4 As the supply yarn, a polyester drawn yarn (54 dtex / 10 filaments) with an elongation of 32%, a single fiber fineness of 5.4 dtex, and a cross-sectional shape of the single fiber being four-lobed was used. Then, false twisting was performed in the same manner as in Example 1, except that the false twist temperature was changed to 180°C according to the process shown in FIG. 2. The characteristic values of the obtained false-twisted yarn are shown in Table 1. Then, using the obtained false-twisted yarn, weaving was performed in the same manner as in Example 1, except that the warp density and weft density were changed to those shown in Table 1, to obtain a plain woven fabric. Subsequently, the obtained plain woven fabric was subjected to scouring and dyeing in the same manner as in Example 1 to obtain a woven fabric. The obtained woven fabric had good stiffness, crispness, and dyed quality.

[0047] Example 5 Using the same supply yarn as in Example 2, false twisting was performed in the same manner as in Example 2, except that the untwisting tension and the twisting tension in the false twisting device were changed to the values shown in Table 1. Table 1 shows the characteristic values of the obtained false-twisted yarns. Then, using the obtained false-twisted yarns, weaving was carried out in the same manner as in Example 2 to obtain a plain woven fabric. Subsequently, the obtained plain woven fabric was subjected to scouring and dyeing processes similar to those in Example 1 to obtain a woven fabric. The obtained woven fabric was good in terms of stiffness, crispness, and dyeing quality.

[0048] Comparative Example 1 Using the same supply yarn as in Example 1, stretching was performed during false twisting according to the process shown in FIG. 3, and heat treatment was carried out with a second heat treatment heater 7 provided between the false twist applying device 3 and the first take-up roller 4. Except for changing the false twisting processing conditions to those shown in Table 1, it was carried out in the same manner as in Example 1. The heat treatment overfeed rate shown in Table 1 is calculated based on the speeds of the first take-up roller 4 and the second take-up roller 8. Table 1 shows the characteristic values of the obtained false-twisted yarns. The obtained false-twisted yarns were flat-ended yarns without untwisted parts and untwisting parts and without torque. Then, using the obtained false-twisted yarns, weaving was carried out in the same manner as in Example 1 except for changing the warp density and weft density to those shown in Table 1 to obtain a plain woven fabric. Subsequently, the obtained plain woven fabric was subjected to scouring and dyeing processes similar to those in Example 1 to obtain a woven fabric. The obtained woven fabric was rigid and inferior in terms of stiffness and crispness.

[0049] Comparative Example 2 Using the same supply yarn as in Example 1, false twisting was carried out in the same manner as in Example 1 except for changing the false twisting temperature to 250°C. Table 1 shows the characteristic values of the obtained false-twisted yarns. The obtained false-twisted yarns were flat-ended yarns in which the single fibers were fused together, without untwisted parts and untwisting parts, and without crimp and torque. Then, using the obtained false-twisted yarns, weaving was carried out in the same manner as in Example 1 except for changing the warp density and weft density to those shown in Table 1 to obtain a plain woven fabric. Subsequently, the obtained plain woven fabric was subjected to scouring and dyeing processes similar to those in Example 1 to obtain a woven fabric. The obtained fabric was rigid, lacked stiffness, crispness, and was inferior in all aspects of dyeing quality.

[0050] Comparative Example 3 The same supply yarn as in Example 1 was used, and false-twist processing was performed to obtain false-twist processed yarn. At this time, stretching was performed during false-twisting, and it was carried out in the same manner as in Example 1 except that the false-twist processing conditions were changed to those shown in Table 1. The characteristic values of the obtained false-twist processed yarn are shown in Table 1. The obtained false-twist processed yarn had no untwisted part. Then, using the obtained false-twist processed yarn, weaving was carried out in the same manner as in Example 1 except that the warp density and weft density were changed to those shown in Table 1, and a plain fabric was obtained. Subsequently, the obtained plain fabric was subjected to scouring and dyeing in the same manner as in Example 1 to obtain a fabric. Since the obtained fabric had no untwisted part in the false-twist processed yarn, the surface feel and touch of the fabric were also different, and it was inferior in terms of stiffness, crispness, and dyeing quality.

[0051] Comparative Example 4 Using the same supply yarn as in Example 2, except that the false-twist draw ratio was changed to 1.55 and the untwisting and twist tension were changed to those shown in Table 1, false-twist processing was carried out in the same manner as in Example 2. The characteristic values of the obtained false-twist processed yarn are shown in Table 1. The obtained false-twist processed yarn had only an untwisted part A and the number was small. Then, using the obtained false-twist processed yarn, weaving was carried out in the same manner as in Example 1 except that the warp density and weft density were changed to those shown in Table 1, and a plain fabric was obtained. Subsequently, the obtained plain fabric was subjected to scouring and dyeing in the same manner as in Example 1 to obtain a fabric. The obtained fabric was inferior in terms of stiffness and crispness.

[0052] Comparative Example 5 Using the same supply yarn as in Example 2, false-twist processing was carried out in the same manner as in Comparative Example 4 except that the false-twist temperature was changed to 190°C. Table 1 shows the characteristic values of the obtained false-twisted yarns. The obtained false-twisted yarns had only untwisted parts A and were few in number. Then, using the obtained false-twisted yarns, weaving was carried out in the same manner as in Example 1 except that the warp density and weft density were changed to those shown in Table 1, and a plain woven fabric was obtained. Subsequently, the obtained plain woven fabric was subjected to scouring and dyeing processes similar to those in Example 1 to obtain a woven fabric. The obtained woven fabric was inferior in stiffness and crispness.

[0053] Comparative Example 6 Using the same supply yarn as in Example 2, false-twisting was carried out in the same manner as in Example 2 except that the false-twisting temperature was changed to 240°C, the false-twisting draw ratio was changed to 1.35, and the untwisting and twisting tensions were changed to those shown in Table 1. Table 1 shows the characteristic values of the obtained false-twisted yarns. The obtained false-twisted yarns had a large number of untwisted parts A and B. Then, using the obtained false-twisted yarns, weaving was carried out in the same manner as in Example 1 except that the warp density and weft density were changed to those shown in Table 1, and a plain woven fabric was obtained. Subsequently, the obtained plain woven fabric was subjected to scouring and dyeing processes similar to those in Example 1 to obtain a woven fabric. The obtained woven fabric was too rigid due to the high false-twisting temperature, resulting in poor stiffness and crispness and inferior dyeing quality.

[0054] Comparative Example 7 Using the same supply yarn as in Example 2, false-twisting was carried out in the same manner as in Example 2 except that the number of false-twists, untwisting, and twisting tensions were changed to those shown in Table 1. Table 1 shows the characteristic values of the obtained false-twisted yarns. The obtained false-twisted yarns had open-ended untwisted parts, and the ratio of the length in the yarn width direction between the untwisted parts and the untwisted parts was large. Then, using the obtained false-twisted yarns, weaving was carried out in the same manner as in Example 1 except that the warp density and weft density were changed to those shown in Table 1, and a plain woven fabric was obtained. Subsequently, the obtained plain woven fabric was subjected to scouring and dyeing processes similar to those in Example 1 to obtain a woven fabric. The obtained woven fabric was inferior in all aspects of stiffness, crispness, and dyeing quality.

[0055]

Table 1

Explanation of Symbols

[0056] 1 Supply roller 2 Heat treatment heater 3 False twist imparting device 4 First take-up roller 5 Winding roller 6 Package of false twist yarn 7 Second heat treatment heater 8 Second take-up roller

Claims

1. A false-twisted yarn made of polyester filaments, in which untwisted portions and twisted portions alternately exist in the longitudinal direction of the yarn, having 40 to 110 untwisted portions with a length of 0.3 to 12 mm in the longitudinal direction of the yarn per meter of the yarn, and a ratio of the length in the width direction of the untwisted portion to the length in the width direction of the twisted portion (untwisted portion / twisted portion) is 1 / 3 to 1 / 14.

2. The false-twisted yarn according to claim 1, having an untwisted portion A with a length of less than 0.3 to 3 mm and an untwisted portion B with a length of 3 to 12 mm as the untwisted portions, having 30 to 85 untwisted portions A per meter of the yarn, and having 3 to 25 untwisted portions B per meter of the yarn.

3. The false-twisted yarn according to claim 1 or 2, wherein the ratio of the total length of the untwisted portions per meter of the yarn to the total length of the twisted portions per meter of the yarn is untwisted portion total length / twisted portion total length = 1 / 3 to 1 / 10.

4. The false-twisted yarn according to any one of claims 1 to 3, wherein the single fiber constituting the false-twisted yarn has a single fiber fineness of 5 to 20 dtex and a multi-lobed shape having 3 to 8 convex portions in a cross section perpendicular to the fiber longitudinal direction.

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