Crimped yarn

Abstract

To provide a crimped composite yarn with a uniform yarn width having a process passability and weavability and capable of obtaining a fabric with a satisfactory fabric grade.SOLUTION: In a crimped yarn made of a composite fiber having a coil diameter of 100 to 300 μm and a coil number of 1.0 to 2.0 pieces / mm, a distance in a vertical direction with respect to a yarn longer direction is 100 to 150 μm and a difference between the maximum value and the minimum value of the distance in the yarn longer direction is 200 μm or less.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a crimped yarn having excellent soft stretchability. More specifically, the present invention relates to a crimped yarn having fine and uniform entanglement, which provides excellent processability and fabrics of excellent quality. [Background technology]

[0002] Synthetic fibers made of polyester, polyamide, etc. have excellent mechanical properties and dimensional stability, and are therefore widely used in a variety of applications, from clothing to non-clothing. As clothing applications become more sophisticated, there is a strong demand for fabrics with stretch properties.

[0003] To meet these demands, many crimped composite fibers have been proposed, in which two types of polymers are bonded side-by-side or eccentrically, and then crimped after heat treatment. Fine-fineness composite fibers offer excellent softness and stretchability.

[0004] However, due to the yarn characteristics of crimped composite fibers, they are prone to defects such as slack, in which single yarns protrude in a loop shape, and fluff, which occurs when the slack rubs against a guide during the manufacturing process. In order to improve the passability and windability during the manufacturing process, a jet of fluid is directed at the yarn in an interlace nozzle during the entanglement treatment step, causing entanglement between the single yarns. However, this actually causes the yarn to collide with the nozzle wall, resulting in defects such as fluff.

[0005] Reducing the amount of fluid injected to reduce the number of times the yarn collides with the nozzle wall surface results in insufficient bundle strength, which can lead to the yarn breaking into single yarns and the generation of slack and fuzz. The occurrence of slack and fuzz leads to poor yarn handling during warping and weaving, making yarn breakage more likely and significantly reducing product productivity. Furthermore, the occurrence of fuzz causes streak-like defects in the fabric quality, making dyeing unevenness more likely. In other words, imparting bundle strength to the yarn without causing defects such as slack and fuzz is an important issue in crimped composite fibers.

[0006] To solve these problems, for example, Patent Document 1 proposes a method of applying a treatment agent containing a specific component, entangling the film before stretching with a jet fluid pressure in the range of 0.08 MPa to 0.15 MPa, and controlling the temperature of the preheating rolls for stretching to 45°C to 49°C, thereby suppressing fusion of polytrimethylene terephthalate molecules and poor stretching during preheating and improving the occurrence of sagging.

[0007] Patent Document 2 proposes a composite polyamide fiber for false twisting that is finely entangled by oiling before entangling to add moisture. It is proposed that adding moisture makes it difficult for single yarns to entangle with each other during entangling, thereby achieving appropriate entanglement and providing sufficient stretchability and excellent fabric quality.

[0008] Patent Document 3 proposes that by suppressing the flow of fluid in the opposite direction to the yarn running direction near the nozzle, it becomes possible to perform entanglement treatment with a fluid at a high fluid injection pressure while suppressing collision damage between the yarn and the nozzle wall surface. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-24575 [Patent Document 2] JP 2018-3190 A [Patent Document 3] Japanese Patent Application Publication No. 2018-127737 Summary of the Invention [Problem to be solved by the invention]

[0010] Although Patent Document 1 proposes entanglement treatment before drawing and control of the preheat roll temperature to prevent fusion between single yarns and poor drawing, it is not possible to perform uniform and fine entanglement treatment while preventing sagging and fuzz. For crimped yarns with a large number of three-dimensional coils and fine crimps, the entanglement treatment method of Patent Document 1 indicates a suitable jet fluid pressure, but does not indicate suitable interlace nozzle specifications, and known nozzle specifications do not result in preventing sagging and fuzz.

[0011] In particular, small slack in crimped yarns having fine crimps is likely to be rubbed and turn into fluff when it collides with the nozzle wall in a known interlace nozzle. When a large amount of fluff is generated, the single yarns get caught and tangled in the guide during warping, which can cause pilling and remain in the fabric, resulting in defects.

[0012] Furthermore, Patent Document 2 proposes adding moisture before entanglement to achieve fine entanglement, but it is unable to achieve uniform entanglement with high entanglement strength while suppressing sagging and fuzz. Although adding moisture effectively reduces friction with the interlace nozzle wall, the nozzles shown in Patent Document 2, which have fluid injection holes arranged opposite each other, are prone to turbulence due to interference from the injected fluid, making it impossible to achieve uniform entanglement quality in the longitudinal direction. Yarns with fine crimps are prone to sagging due to their yarn characteristics, and large loops of sagging are likely to occur because the single yarns do not entangle uniformly due to pressure fluctuations caused by turbulence or contamination of the injected fluid or clogging of the injection holes. Furthermore, large loops of sagging are prone to friction and fuzz during advanced processing, and are also prone to streaks on the fabric due to uneven tension and uneven entanglement during the process.

[0013] Furthermore, Patent Document 3 proposes suppressing fuzz by suppressing the flow of fluid in the opposite direction to the yarn running direction, but it is not possible to achieve uniform entanglement treatment with high entanglement strength while suppressing slack and fuzz. The backflow of the injected fluid toward the yarn introduction side of the nozzle is suppressed to reduce loosening of process tension and friction with the nozzle wall, but because the yarn path where the yarn is entangled and opened is wide, the yarn exposed to the injected fluid is likely to open into loops of various sizes, easily resulting in large slack loops. The formation of large loops makes it difficult to handle the yarn during weaving, which can easily lead to yarn breakage and streak-like defects on the fabric.

[0014] Simply applying the methods described in Patent Documents 1, 2, and 3 tends to result in large loop slack, making it impossible to provide crimped yarn that is excellent in processability and fabric quality. [Means for solving the problem]

[0015] In order to solve the above problems, the present invention comprises the following configuration. (1) A crimped yarn made of a composite fiber having a coil diameter of 100 μm to 300 μm and a coil number of 1.0 / mm to 2.0 / mm, and a distance in a direction perpendicular to the longitudinal direction of the yarn Average value of and the difference between the maximum and minimum values ​​of the distance in the longitudinal direction of the yarn is 200 μm or less. (2) The crimped yarn according to (1) above, in which the CV% (coefficient of variation) of the distance in the direction perpendicular to the longitudinal direction of the yarn is 5% to 25%. (3) Crimped yarn according to (1) or (2) above, having a CF value of 10 to 30. (4) The crimped yarn according to any one of (1) to (3) above, wherein the single yarn fineness of the conjugate fiber is 0.5 dtex to 3.0 dtex. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide crimped yarns that are free from slack and have fine and uniform entanglement. [Brief explanation of the drawings]

[0017] [Figure 1]1 is a schematic diagram of the crimp morphology of a conjugate fiber of the present invention. [Figure 2] FIG. 10 is a schematic diagram illustrating the position at which the distance in the direction perpendicular to the longitudinal direction of the yarn is measured. [Figure 3] FIG. 2 is a schematic diagram of an example of an interlace nozzle before stretching suitable for the production method of the present invention. [Figure 4] FIG. 2 is a schematic diagram of an example of an interlace nozzle before winding, suitable for the production method of the present invention. [Figure 5] 1 is a schematic diagram of a spinning facility showing one embodiment of the present invention. [Figure 6] FIG. 10 is an explanatory diagram of a method for measuring a distance in a direction perpendicular to the longitudinal direction of the yarn. [Figure 7] FIG. 2 is a schematic diagram showing an example of crimped and non-crimped portions in the longitudinal direction of the yarn. [Figure 8] FIG. 2 is a chart showing data results obtained by measuring yarn morphology in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0018] The crimped yarn of the present invention will be described below.

[0019] The synthetic fibers constituting the crimped yarn of the present invention are fibers made of high molecular weight polymers, and fibers made of thermoplastic polymers produced by melt spinning, etc. The synthetic fibers are composite fibers in which two or more polymer components are arranged.

[0020] Examples of thermoplastic polymers constituting the synthetic fibers of the present invention include melt-moldable polymers such as polyethylene terephthalate or its copolymers, polyethylene naphthalate, polytrimethylene terephthalate, polypropylene, polyolefin, polycarbonate, polyacrylate, polyamide, polylactic acid, thermoplastic polyurethane, etc. Among these thermoplastic polymers, polycondensation polymers such as polyester and polyamide are preferred because they are crystalline and have relatively high melting points, and therefore do not deteriorate even when heated at relatively high temperatures during heat treatment steps in post-processing and in actual use (washing, dry cleaning, etc.).

[0021] The thermoplastic polymer may contain various additives, such as inorganic substances such as titanium oxide, silica, and barium oxide, colorants such as carbon black, dyes, and pigments, flame retardants, fluorescent brighteners, antioxidants, and ultraviolet absorbers, as long as the effects of the present invention are not impaired.

[0022] To obtain good crimp properties, the composite fiber of the present invention has a configuration in which high-viscosity and low-viscosity polymers are bonded side-by-side or an eccentric sheath-core configuration. By forming polymers with different viscosities into a side-by-side or eccentric sheath-core cross section, stress is concentrated on the high-viscosity side during spinning and drawing, resulting in different internal strains between the components. Therefore, due to differences in elastic recovery after drawing and differences in thermal shrinkage during the heat treatment process of the fabric, the high-viscosity side shrinks significantly, causing strain within the single fiber and resulting in a three-dimensional coil configuration. The eccentric sheath-core configuration refers to a configuration in which the center of gravity of the core component polymer in the composite fiber cross section is different from the center of the composite fiber cross section. It is also preferable that the high-viscosity polymer component is covered by the low-viscosity polymer component. Complete coverage of the high-viscosity polymer component by the low-viscosity polymer component makes it less likely to cause whitening or fuzzing even when the fiber or fabric is subjected to friction or impact, making it easier to maintain fabric quality.

[0023] The three-dimensional coil diameter and the number of coils per unit fiber length, i.e., the number of crimps, of the composite fiber of the present invention are determined by the difference in shrinkage between the high-viscosity polymer component and the low-viscosity polymer component. The coil diameter of the composite fiber is 100 μm to 300 μm, and the number of coils of the composite fiber is 1.0 / mm to 2.0 / mm. By setting these ranges, the coil crimp characteristics required for a stretch material can be obtained. The coil diameter and number of coils referred to here refer to the coil diameter and number of coils when the crimp morphology of a single fiber is observed under an optical microscope. Specifically, the crimped yarn was disassembled, and the crimp morphology of each single fiber was observed under a digital microscope. The coil diameter was determined as the distance between the peaks and valleys in the crimp phase (Figure 1-2), and the number of peaks per unit fiber length (Figure 1-3) was determined as the number of coils.

[0024] The crimped yarn of the present invention has a distance (X) (Fig. 2-6) perpendicular to the longitudinal direction of the yarn, as shown in Figure 2, of 100 μm to 150 μm. This distance (X) indicates the dispersion state of the single yarns perpendicular to the longitudinal direction of the yarn, with a larger value indicating a more dispersed state and a smaller value indicating a more entangled and focused state. By achieving this range, an appropriate dispersion state of the yarns can be obtained, resulting in excellent processability and fabric quality suitable for clothing applications. If the distance (X) is less than 100 μm, the yarns will be thin and tight, resulting in gaps between adjacent yarns when woven into a fabric, resulting in fabric with streak-like defects. If the distance (X) exceeds 150 μm, the yarns will be thick and dispersed, resulting in single yarn breakage due to contact between adjacent yarns during warping and weaving, resulting in poor processability. Furthermore, gaps will be formed between adjacent yarns on the fabric, resulting in fabric with streak-like defects. Furthermore, as applications become more sophisticated, the distance is preferably in the range of 110 μm to 140 μm, which allows for better fabric quality to be obtained.

[0025] In the crimped yarn of the present invention, the difference (R) between the maximum and minimum distances in the direction perpendicular to the yarn longitudinal direction, as shown in Figure 2, is 200 µm or less. This difference (R) between the maximum and minimum values ​​indicates the dispersion state of single yarns in the yarn longitudinal direction, with a larger value indicating a more non-uniform entanglement state and a smaller value indicating a more uniform entanglement state. Setting the difference (R) within this range makes the entanglement state of the yarn uniform. That is, the difference in shape between the entangled portions and the spread portions is reduced, thereby reducing the apparent unevenness of the yarn and achieving excellent fabric quality. If the difference (R) exceeds 200 µm, a difference in shape occurs between the entanglement points of the yarn and the large loop spread portions, resulting in an apparent unevenness of the yarn. The local unevenness, i.e., slack in the single yarn, generates fuzz and the fabric has streak-like defects due to the unevenness. Furthermore, with the increasing sophistication of applications, it is preferable that the difference (R) between the maximum and minimum values ​​is 150 µm or less. Furthermore, for yarns for high-density thin fabrics with a total fineness of 30 dtex or less, the difference (R) between the maximum and minimum values ​​is preferably 100 μm or less. By setting it in this range, the effect of a small single yarn fineness can be reduced.

[0026] The crimped yarn of the present invention preferably has a CV% (coefficient of variation) of 5% to 25% for the distance perpendicular to the longitudinal direction of the yarn, as shown in Figure 2. This CV% for distance indicates the dispersion state of single yarns perpendicular to the longitudinal direction of the yarn, with a larger value indicating a more non-uniform entanglement state depending on the fineness, and a smaller value indicating a more uniform entanglement state depending on the fineness. By setting the CV% for distance within this range, the entanglement state of the yarn becomes uniform in the longitudinal direction. When weft insertion is performed on a water jet loom, the yarn is held in the accumulator for the length to be inserted. Because the entanglement is uniform in the longitudinal direction, even when tension is applied to the yarn, the entanglement is less likely to loosen or unravel, and the weft yarn can be held with uniform tension. Furthermore, when made into a fabric, the gaps between adjacent yarns are uniform, resulting in a fabric without streaks. By setting the CV% for distance to 25% or less, variation in the entanglement state is suppressed, and the entanglement is less likely to loosen or unravel partially when high tension is applied during advanced processing. Furthermore, for yarns for high-density thin fabrics with a total fineness of 30 dtex or less, the distance CV% is preferably 20% or less. By setting it in this range, the effect of a small single yarn fineness can be reduced.

[0027] The distance perpendicular to the longitudinal direction of the yarn is measured using a dimension measuring instrument (Keyence Corporation, Ultra-High-Speed, High-Precision Dimension Measuring Instrument LS-9006). Specifically, the yarn unwound from the yarn package at a speed of 100 m / min was passed, under constant tension, between a light projecting unit that irradiates the yarn and a detector that detects the amount of irradiated light. The position information for each of the yarns was measured based on the change in the amount of light blocked by the single yarn group. The sampling frequency was 4000 times / second or more, and the measurement distance was 30 m. The dimension measuring instrument was positioned perpendicular to the line connecting a pair of alumina slit guides, which are yarn guide means, and the distance perpendicular to the longitudinal direction of the yarn was measured. Using a computing device, the average distance (X) calculated from all measurement data and the largest value (R) between the maximum and minimum values ​​every 1 m were calculated. The standard deviation divided by the average value was used to calculate the CV% (coefficient of variation) of the distance.

[0028] The CF value of the crimped yarn of the present invention is preferably 10 to 30. By setting it in this range, the entanglement state of the yarn becomes uniform, and the yarn does not come apart during warping or weaving. Since the yarn does not loosen or unravel, streaks due to single yarn unraveling do not occur in the fabric, and a fabric with excellent quality can be obtained. When the CF value is 10 or more, sufficient binding force can be obtained, so the yarn is less likely to come apart even when tension is applied, and when the CF value is 30 or less, the distance of the entangled parts is short, so that a difference in shape with the spread parts is less likely to occur, and sagging is less likely to occur. A more preferable CF value range is 15 to 25.

[0029] The CF value here is measured using an entanglement tester (Entanglement Tester R-2060 manufactured by Rothschild) according to the method described in JIS L 1013 (2010). Specifically, a needle with a constant tension is run between groups of single yarns on a yarn unwound from a yarn package at a speed of 5 m / min, and the frequency at which the tension exceeds a specified value (reference tension 10 g, threshold tension 15 g) at the entanglement point is measured. A 150 m measurement is performed, and the CF value is calculated by dividing the distance by the number of entanglement judgments.

[0030] The fineness of the crimped yarn of the present invention is not particularly limited, but considering its use in clothing applications such as innerwear, sportswear, and casual wear, it is preferably 15 dtex to 250 dtex, and as the applications become more sophisticated, it is preferably 15 dtex to 100 dtex.

[0031] The number of filaments in the crimped yarn of the present invention is preferably as many as possible, preferably six or more, from the viewpoint of achieving a bundled state with many fine entanglements. As the number of filaments increases, the number of microscopically complex voids between the single filaments increases, allowing for a balanced expression of a light, flexible, and resilient texture. Furthermore, the number of intermingled single filaments increases in accordance with the number of filaments, making it easier for entanglement to occur.

[0032] The single yarn fineness of the conjugated fiber of the present invention is preferably 0.5 dtex to 3.0 dtex. A single yarn fineness of 0.5 dtex or more enables industrially stable spinning, while a single yarn fineness of 3.0 dtex or less provides a sufficiently soft feel when used in fabrics made from the crimped yarn of the present invention. The smaller the single yarn fineness, the softer the fabric will be, so a single yarn fineness of 0.5 dtex to 2.5 dtex is preferred. To achieve the above single yarn fineness, the discharge rate and spinneret (number of holes) may be appropriately adjusted in the production process. The smaller the single yarn fineness of the crimped yarn of the present invention, the more likely it is that slack will rub against the interlace nozzle wall, causing fluffing, and the crimped yarn is more susceptible to the effects of entanglement conditions. Within this fineness range, the entangled state of the present invention provides a fabric without streaky defects and a soft feel.

[0033] The crimped yarn of the present invention preferably has a breaking strength in the range of 3.0 cN / dtex to 4.5 cN / dtex. By making the breaking strength 3.0 cN / dtex or more, good tear strength can be obtained in the fabric. Furthermore, if the breaking strength is high, whitening and fluffing are likely to occur in the fabric due to friction, etc., so it is preferable to make it 4.5 cN / dtex or less. In order to suppress whitening and fluffing, a more preferable breaking strength is in the range of 3.0 cN / dtex to 4.0 cN / dtex.

[0034] The crimped yarn of the present invention preferably has a breaking elongation in the range of 20% to 80%. By making the breaking elongation 20% or more, it is possible to prevent yarn breakage during drawing, enabling industrially stable production, and from the viewpoint of advanced processability, it is preferable to make it 80% or less. For stable advanced processability, a more preferable breaking elongation is in the range of 30% to 70%.

[0035] The crimped yarn of the present invention preferably has a stretching extension percentage in the range of 40% to 150%. The stretching extension percentage is a value that indicates the degree of crimp, with a higher value indicating higher stretch performance. From the perspective of dimensional stability, the stretching extension percentage is preferably 150% or less, and for formal applications such as women's and men's clothing, a stretching extension percentage in this range can achieve both excellent stretchability and dimensional stability. To obtain even better dimensional stability, a more preferred stretching extension percentage is in the range of 50% to 120%.

[0036] The crimped yarn of the present invention preferably has a crimp expression rate of 80% or more. The crimp expression rate is calculated from the ratio of the crimped portion to the non-crimped portion in the longitudinal direction of the yarn. A crimp expression rate of 80% or more results in a high elastic elongation rate and excellent stretchability. A crimp expression rate of 90% or more is more preferable because it eliminates variation in the longitudinal direction of the yarn and improves fabric quality.

[0037] For the crimped yarn of the present invention, it is important to impart appropriate entanglement in order to achieve good crimp expression, suppress sagging and fluffing, and achieve a good crimp morphology. The present inventors have found that by imparting sufficient entanglement according to the coil characteristics in order to suppress crimp variation between single yarns, which is a cause of sagging defects, it is possible to uniform the crimp state in the yarn longitudinal direction and obtain a crimped yarn that is free of sagging and fluffing and has excellent processability.

[0038] Next, a preferred method for producing the crimped yarn of the present invention will be described.

[0039] The method for producing crimped yarn of the present invention is characterized by a two-stage entanglement process, which consists of an entanglement process before drawing for the purpose of uniformly dispersing the yarns, and an entanglement process before winding for the purpose of increasing the number of entanglement points with low binding force. In the entanglement process before drawing, twin-flow jets of fluid are directed at the single yarn group to disperse the single yarn group, and in the entanglement process before winding, a jet of fluid rotating at high speed is directed at the single yarn group to increase the entanglement-opening frequency of the single yarn group.

[0040] The entanglement treatment of the crimped yarn of the present invention is a two-stage entanglement treatment in which entanglement treatment is carried out before drawing and before winding. Preferred interlace nozzles for each are shown in Figs. 3 and 4.

[0041] In FIG. 3, the cross-sectional area of ​​the yarn path 10 of the interlace nozzle 7 used before drawing gradually expands toward the yarn outlet side after passing through the injection hole, and it is preferable that the maximum value 11 of the cross-sectional area of ​​the yarn path is increased by 20% to 80% compared to the cross-sectional area of ​​the yarn path 10 at the injection hole. As the cross-sectional area of ​​the yarn path gradually expands after passing through the injection hole, the mixed single yarns are uniformly dispersed and the oil is uniformly applied. Uniform dispersion of the yarns can prevent fusion of the single yarn surfaces during drawing, resulting in a crimped yarn with uniform physical properties without uneven drawing. Furthermore, the twin flows generated by the collision of the jet fluid with the nozzle wall surface are efficiently applied to the single yarns, and the cross-sectional area of ​​the yarn path expands, resulting in a uniform entanglement state because the single yarns are entangled without forming large spread portions. The cross-sectional area of ​​the yarn path referred to here is the narrowest area through which the yarn can pass when observed using an optical microscope from the direction of the yarn running axis of the nozzle, and the area at the yarn outlet end of the nozzle is set to the maximum value 11.

[0042] In FIG. 4, the cross-sectional area of ​​the yarn path 10 of the interlace nozzle 13 used before winding is different from that of the interlace nozzle 7 before drawing, and the cross-sectional area of ​​the yarn path is kept constant even after passing through the injection hole, and the cross-sectional area of ​​the yarn path is 0.5 mm 2 ~1.0mm 2 By setting the rotational speed in this range, a swirling flow with high rotation speed and a small diameter is generated in the nozzle, and the single yarns are entangled without forming large spread portions. Therefore, the frequency of switching between entangled portions and spread portions is high, and uniform entanglement quality in the yarn longitudinal direction can be obtained.

[0043] The ratio of the maximum value 11 of the cross-sectional area of ​​the yarn path of the interlace nozzle before drawing to the cross-sectional area of ​​the yarn path 10 of the interlace nozzle before winding is preferably in the range of 5:1 to 8:1. By setting the ratio in this range, the yarn distribution before winding can be made uniform, and contact between the yarn entrance side wall surface of the interlace nozzle before winding and the slack in the yarn can be prevented, thereby suppressing the generation of fuzz. Typically, during entanglement, the process tension is relaxed and the entanglement is performed inside the interlace nozzle. Therefore, the jetted fluid ejected in the reverse direction toward the yarn entrance side can collide with the yarn, causing it to slacken. Setting the ratio of the cross-sectional areas of the yarn path in this range limits the width between the individual yarns, making it easier for the yarn to enter the interlace nozzle before winding. Setting the ratio to 5:1 or more makes it easier for the yarn to smoothly enter the interlace nozzle before winding, preventing contact between the yarn entrance side wall surface of the interlace nozzle and the slack in the yarn, thereby suppressing the generation of fuzz. In other words, the difference (R) between the maximum and minimum yarn distances in the direction perpendicular to the yarn longitudinal direction can be controlled to be small. By setting the ratio to [8:1] or less, the yarn path when the yarn enters the pre-winding interlace nozzle can be regulated, and the yarn can run over the injection holes and be efficiently entangled. In other words, the CV% of the distance perpendicular to the yarn longitudinal direction can be reduced.

[0044] In addition, in the interlace nozzle before drawing, the angle 12 between the yarn running axis and the fluid injection hole is preferably 75° to 85°. The injected fluid is usually discharged in the yarn running direction, following the running yarn. However, if turbulence occurs in the nozzle, the injected fluid may be reverse-ejected toward the yarn introduction side of the nozzle, opposite the yarn running direction. The reverse-ejected fluid may cause the yarn to slacken, causing the slackened yarn to strike the nozzle wall and generate fuzz. Therefore, by providing the fluid injection hole at an angle of 85° or less with respect to the yarn running axis, the injected fluid can be actively urged in the direction opposite to the yarn running direction. Furthermore, by setting the angle at 75° or more, a swirling flow is likely to occur when the fluid injected from the fluid injection hole strikes the opposing nozzle wall, resulting in entanglement with sufficient restraint force. This is a preferred embodiment because the crimped yarn of the present invention is prone to fuzz due to friction with slack.

[0045] The hole diameter of the fluid injection holes 9 of the interlace is preferably Φ0.8 mm to Φ2.0 mm, and compressed air of 0.10 MPa to 0.40 MPa is preferably used as the injected fluid. By using such a range, the necessary amount of injected fluid can be secured, and entanglement with sufficient binding force can be achieved. Furthermore, by using a nozzle with a fluid injection hole diameter of Φ2.0 mm or less and using compressed air of 0.4 MPa or less as the injected fluid, the frequency of collision between the nozzle wall surface and slack yarns can be reduced, thereby reducing the risk of fuzz generation. Furthermore, the hole diameter of the fluid injection holes of the interlace nozzle before winding is preferably Φ1.4 mm or less. By using such a range, a swirling flow with high rotation speed is generated, making it easier to achieve entanglement with a high frequency of switching between entangled portions and spread portions.

[0046] In addition, the ratio of the fluid pressure jetted from the interlace nozzle before drawing to the fluid pressure jetted from the interlace nozzle before winding is preferably 1:1.4 to 1:3.4, and it is desirable to perform the entanglement treatment in a balanced manner. By setting the ratio within this range, the apparent unevenness of the yarn is reduced. If the entanglement treatment is not performed before drawing and is performed strongly before winding, entanglement points with strong binding force are likely to be created. Therefore, it is preferable to perform the entanglement treatment at a pressure ratio of [1:3.4] or less. A ratio of 1:1.5 to 1:2.5 is even more preferable.

[0047] By setting the range in this way, the entanglement becomes uniform in the longitudinal direction of the yarn, and the CV% of the distance in the direction perpendicular to the longitudinal direction of the yarn can be reduced.

[0048] The intrinsic viscosity (IV) of the polymer in the present invention is preferably in the range of 0.7 to 2.0 for the high-viscosity polymer component. By setting the intrinsic viscosity to 0.7 or more, it becomes easy to produce fibers that combine sufficient strength and elongation. A more preferred intrinsic viscosity is 0.8 or more. Furthermore, by setting the intrinsic viscosity to 2.0 or less, production stability is easily achieved. A more preferred intrinsic viscosity is 1.8 or less. On the other hand, the low-viscosity polymer component is preferably 0.4 or more. A more preferred intrinsic viscosity is 0.5 or more. By setting it in this range, stable spinnability can be achieved. Even more preferably, by setting the intrinsic viscosity to 0.7 or less, high crimp properties can be achieved.

[0049] In the present invention, in order to obtain a raw yarn with excellent crimp properties, the difference in intrinsic viscosity between the high-viscosity polymer component and the low-viscosity polymer component is preferably 0.3 or more. Increasing the intrinsic viscosity difference to 0.5 or more results in a raw yarn with even better stretchability. On the other hand, if the intrinsic viscosity difference exceeds 1.5, although the obtained yarn has good crimp properties, the spun yarn will bend excessively toward the high-viscosity component, making it impossible to stably spin for a long period of time. Therefore, in order to satisfy both stable spinnability and stretch recovery, it is desirable that the intrinsic viscosity difference be in the range of 0.3 to 1.5.

[0050] The intrinsic viscosity here is the value calculated by dissolving 0.8 g of a sample polymer in 10 mL of o-chlorophenol with a purity of 98% or higher at 25°C, and determining the relative viscosity at 25°C using an Ostwald viscometer.

[0051] The conjugation ratio of the high-viscosity component to the low-viscosity component of the conjugated fiber of the present invention is preferably in the range of 80:20 to 20:80 (wt %) of high-viscosity component:low-viscosity component in terms of spinnability, expression of crimp performance, and dimensional uniformity of the coil in the fiber length direction, and a more preferred conjugation ratio is in the range of 70:30 to 30:70. The conjugation ratio defined in the present invention is the ratio (cross-sectional area × polymer density) of the two polymer components constituting a single fiber in the cross section of the single fiber.

[0052] The spinning method for the crimped yarn of the present invention is not particularly limited and can be based on known techniques. As shown in Fig. 5, yarn 16 discharged from spinneret 14 passes through cooling device 17, is oiled by oiling device 18, is entangled by first entanglement treatment device 19, is taken up by first godet roller 20 and second godet roller 21, is again entangled by second entanglement treatment device 22, and is then wound on winder 23.

[0053] The drawing method for the crimped yarn of the present invention is not particularly limited and can be based on known techniques. For example, it can be suitably selected from the following: a method of one-stage heating and drawing between a first hot roll and a second hot roll; a method of one-stage heating and drawing between a first hot roll, an unheated roll, and a hot roll between them; a method of first-stage heating and drawing between a first hot roll and a second hot roll; and a method of second-stage heating and drawing between a second hot roll and a third hot roll. The drawing temperature is not particularly limited, but it is preferably set to a temperature that prevents the surfaces of the single yarns from fusing together. Although this depends on the polymer, polymers with low glass transition points tend to soften on the hot rolls, potentially causing the surfaces of the single yarns to fuse together. Therefore, in multi-stage drawing, the temperature of the first hot roll is preferably 50°C to 80°C, and the temperature is gradually increased from the second hot roll onwards, with the temperature of the final hot roll preferably being in the range of 120°C to 180°C. The draw ratio of the crimped yarn of the present invention is preferably 2.0 to 4.0 times, more preferably 2.5 to 3.5 times.

[0054] The spinning and drawing method of the present invention may be a two-step method in which the spun undrawn yarn is wound up and drawn in a drawing machine, or a one-step method in which the undrawn yarn is drawn immediately after being wound up. In either step method, it is important to carry out an appropriate entanglement treatment before drawing and before winding.

[0055] It is preferable that an oil be applied to the fiber surface of the crimped yarn of the present invention in order to improve smoothness, abrasion resistance, and electrostatic properties. The method for applying the oil is not particularly limited and can be based on known techniques. For example, either an oiling roller method or guide oiling method may be used. In either method, oiling the yarn discharged from the spinneret after it has been cooled and solidified through a cooling device can reduce friction with the yarn path guide in the spinning process and stabilize the yarn running properties over the guides and rollers.

[0056] The crimped yarn of the present invention can be suitably used as a stretch woven knitted fabric, for example, in women's and men's clothing such as shirts, blouses, pants, suits, etc. As a fabric, the crimped yarn may be used alone as the warp and weft, or may be mixed or interwoven with other yarns, and any method that allows the characteristics of the crimped yarn of the present invention to be exhibited may be used without any problems. [Example]

[0057] The present invention will be described in detail below with reference to examples, but is not limited to these examples. Measurement values ​​in the examples were measured by the following methods.

[0058] (1) Intrinsic viscosity (IV) (polyester) The intrinsic viscosity (IV) was calculated from the definition of ηr by dissolving 0.8 g of a sample polymer in 10 mL of o-chlorophenol (hereinafter abbreviated as OCP) with a purity of 98% or higher at 25°C, and determining the relative viscosity ηr using an Ostwald viscometer at 25°C using the following formula: For PTT, 0.8 g of a sample polymer was dissolved in 10 mL of OCP with a purity of 98% or higher at 160°C, and after cooling to 25°C, the intrinsic viscosity (IV) was calculated from the relative viscosity ηr using an Ostwald viscometer using the following formula: ηr=η / η0=(t×d) / (t0×d0) Intrinsic viscosity (IV)=0.0242ηr+0.2634 where η is the viscosity of the polymer solution, η0 is the viscosity of the OCP, t is the solution drop time (seconds), and d is the density of the solution (g / cm 3), t0: OCP fall time (sec), d0: OCP density (g / cm 3 ).

[0059] (2) Melt viscosity The sample polymer was dried in a vacuum dryer to a moisture content of 200 ppm or less, and the melt viscosity was measured by a Toyo Seiki Capillograph 1B at a strain rate of 5 minutes, with the same temperature as the spinning temperature. -1 The value of is evaluated as the melt viscosity of the polymer. The spinning temperature is the temperature at which the polymers used, mainly those with high melting points or high viscosity, show fluidity. The temperature at which this fluidity is shown varies depending on the molecular weight, but is set between the melting point of the polymer and (melting point + 60)°C.

[0060] (3) Melting point of the polymer The sample polymer was dried in a vacuum dryer to a moisture content of 200 ppm or less, and approximately 5 mg was weighed out. A differential scanning calorimeter (DSC) Model Q2000 manufactured by TA Instruments was used to measure the sample by heating it from 0°C to 300°C at a heating rate of 16°C / min, and then holding it at 300°C for 5 minutes. The melting point was calculated from the melting peak observed during the heating process. Each sample was measured three times, and the average value was taken as the melting point. When multiple melting peaks were observed, the melting point was determined to be the top of the highest melting peak.

[0061] (4) Relative viscosity of sulfuric acid (polyamide) 0.25 g of the sample polymer was dissolved in 100 ml of 98 wt% sulfuric acid to adjust the concentration to 1 g / L, and the flow time (T1) at 25°C was measured using an Oswald viscometer. Subsequently, the flow time (T2) of the 98 wt% sulfuric acid alone was measured. The ratio of T1 to T2, i.e., T1 / T2, was defined as the relative viscosity of sulfuric acid.

[0062] (5) Coil diameter (μm) The yarn was broken down into individual single yarns, and the coil diameter (μm) was determined by observing the crimp morphology from the center of the coil using a digital microscope manufactured by KEYENCE Corporation. The coil diameter was determined by drawing lines parallel to the center of the coil at the peaks of the crimp morphology as shown in Figure 1, and determining the distance between the two points where a line perpendicular to the two lines intersects. Measurements were taken at 10 random locations per single yarn, and the number average of the results obtained for 10 different single yarns was used as the coil diameter (μm).

[0063] (6) Number of coils (pcs / mm) The yarn was broken down into individual single yarns, and the crimp morphology was observed from the center of the coil using a digital microscope manufactured by KEYENCE Corporation. The distance between crimps in the crimp phase (μm) was taken as the coil pitch. The distance between 20 crimps per single yarn was measured, and the number average of the results obtained for 10 different single yarns was taken as the number of coils (pieces / mm).

[0064] (7) Total fineness (dtex) A 500 m length of yarn was spooled, and the mass (g) of the skein was multiplied by 20 to obtain the fineness.

[0065] (8) Breaking strength (cN / dtex) and breaking elongation (%) Measurement was carried out in accordance with JIS L 1013 (2010) using Orientec Tensilon UCT-100.

[0066] (9)Stretching rate (%) Measurement was carried out in accordance with JIS L 1013 (2010) Section 8.11, Method C (convenient method). The wet heat treatment was carried out by immersing the sample in 90°C hot water for 20 minutes and then air drying for 5 hours or more.

[0067] (10)CF value Measurement was performed using an ENTANGLEMENT TESTER R-2060 manufactured by Rothschild in accordance with JIS L 1013 (2010). Specifically, a needle was run between single yarn groups while applying a constant tension to a yarn unwound from a fiber package at a speed of 5 m / min, and the frequency at which the tension at the entanglement point exceeded a specified value (reference tension 10 g, threshold tension 15 g) was measured. The measurement was performed over a distance of 150 m, and the CF value was calculated by dividing the distance by the number of entanglement judgments.

[0068] (11) Distance of the yarn perpendicular to the longitudinal direction of the yarn, CV% As shown in Figure 6, the yarn was passed through a tensor guide (Yusa Shido Kogyo Co., Ltd.) made of alumina, which served as a tensioning means 25 and was placed 400 mm from the package stand 24. The tension at the tensor guide outlet was adjusted to 0.15 cN / dtex. A Keyence ultra-high-speed, high-precision dimension measuring instrument 26 (LS-9006) was then placed 50 cm from the tensor guide. The yarn was run through alumina slit guides (2 mm slit width) at 5 cm intervals before and after the tensor guide. The yarn was fed around a yarn feed roller 27, and the running speed was controlled at 100 m / min. The sampling frequency was 4000 times / s, and the measurement distance was 30 m. The dimension measuring instrument was positioned perpendicular to the line connecting the pair of alumina slit guides. The distance of the thread perpendicular to the longitudinal direction of the thread was measured, and the average value of all the data obtained using the built-in calculation device was determined as the distance (X), the largest difference between the maximum and minimum values ​​every 1 m as (R), and the value obtained by dividing the standard deviation by the average value as the CV% (coefficient of variation).

[0069] (12) Crimp occurrence rate (%) The crimp rate per meter was calculated by lining up 1m of yarn in an unloaded state and measuring the distance where crimps like those in the crimped portion of Figure 7 had occurred. Measurements were made over 10m of each yarn, and the number average of the results obtained for five different yarns was taken as the crimp rate.

[0070] (13) Number of sagging and fluffing particles (per 10 million m) The packaged yarn was put on a warper equipped with a fluff detector and taken up at a speed of 600 m / min. The number of slacks and fluffs 3 mm or longer was counted. A total of 50,000 m was measured, and the average number per 10,000,000 m was calculated.

[0071] (14) Fabric quality The fabric was woven using a water jet loom, with the basis weight adjusted according to the total fineness of the yarn used. The weaving properties were evaluated by visually checking the appearance of streaks that appeared when the fabric was passed through in a certain direction per 100 m, and the presence or absence of streaks was evaluated on a two-point scale.

[0072] 〇: Good (no streaky defects) ×: Poor (streaky defects present). (15) Weaving evaluation In addition, the number of times the machine was stopped due to thread breakage during weaving was evaluated on the following two-point scale.

[0073] 〇: Good (Number of thread breaks: less than 3 times) ×: Bad (Number of thread breaks: 3 or more) Example 1 The high-viscosity polymer component was polytrimethylene terephthalate (intrinsic viscosity 1.43, specific gravity 1.16), and the low-viscosity polymer component was polyethylene terephthalate (intrinsic viscosity 0.51, specific gravity 1.19). The high-viscosity polymer and the low-viscosity polymer were melted at 250°C and 285°C, respectively, using an extruder. Then, the high-viscosity and low-viscosity polymers were pumped to a weight ratio of 50:50 to obtain a 56 dtex. The resulting mixture was then pumped through a spinneret formed to form 24 filaments with a side-by-side cross-section. The yarn discharged from the spinneret at a spinning temperature of 270°C was cooled and solidified through a cooling device, then oiled through an oiling device, and entangled in a first entanglement treatment device. The yarn was then taken up by a first godet roller set at a surface temperature of 55°C at a speed of 1250 m / min. Without winding, it was continuously heat-treated and drawn by a second godet roller set at a surface temperature of 130°C at a speed of 4200 m / min. The drawn yarn was entangled in a second entanglement treatment device, tensioned by a godet roller set at a speed of 4010 m / min, and wound into a cheese-shaped package at a speed of 3980 m / min. At this time, the jet fluid pressure of the interlace nozzle in the first entanglement treatment (before drawing) was 0.12 MPa, and the maximum cross-sectional area of ​​the yarn path was 7.5 mm. 2 The nozzle used had the following specifications: 50% increase rate, 1.9 mm diameter of injection hole, and 80° angle between the axis of the yarn traveling through the nozzle and the fluid injection hole. The injection fluid pressure of the interlace nozzle for the second interlacing treatment (before winding) was 0.40 MPa, and the cross-sectional area of ​​the yarn path was 1.1 mm. 2 A nozzle with an injection hole diameter of 1.4 mm was used.

[0074] The evaluation results of the obtained polyester crimped composite yarn are shown in Table 1. The yarn of Example 1 maintained the distance perpendicular to the longitudinal direction of the yarn and had little unevenness in the yarn width. When the obtained raw yarn was woven, no yarn breakage occurred, and the processability and fabric quality were good.

[0075] Example 2 The maximum cross-sectional area of ​​the interlace nozzle before drawing is 5.5 mm 2 , the cross-sectional area of ​​the interlace nozzle before winding is 0.7 mm2 A crimped composite yarn was obtained in the same manner as in Example 1, except for changing the above.

[0076] Compared with Example 1, the number of sagging and fluffing was significantly improved, and the processability and fabric quality were also good.

[0077] Example 3 A crimped composite yarn was obtained in the same manner as in Example 2, except that the injection hole diameter of the interlace nozzle before winding was changed to Φ1.2 mm and the fluid injection pressure ratio used in the entanglement treatment before drawing and before winding was changed to 2.7. Compared to Example 2, the sagging and fuzz counts were significantly improved, and the processability and fabric quality were also good.

[0078] (Examples 4 and 5) A crimped composite yarn was obtained in the same manner as in Example 3, except that the fluid injection pressure ratios before drawing and before winding were changed to 2.5 and 2.3, respectively. Compared to Example 3, the lower the pressure ratio, the more improved the number of slacks and fluffs, and the processability and fabric quality were also good.

[0079] Figure 8(a) shows the measurement results for Example 5, with the apparent yarn width on the vertical axis and the measurement position on the horizontal axis. The yarn of Example 5 had little unevenness in the yarn width, significant improvements in sagging and fuzz count, and good fabric quality.

[0080] (Comparative Example 1) A crimped composite yarn was obtained in the same manner as in Example 1, except that the fluid injection pressure of the interlace nozzle before drawing was changed to 0.10 MPa and the fluid injection pressure ratio before drawing and before winding was changed to 4.0. The yarn had a large amount of slack and fluff, yarn breakage occurred four times during weaving, which deteriorated processability, and the fabric had streak-like defects and was of poor quality.

[0081] (Comparative Example 2) The cross-sectional area of ​​the interlace nozzle before winding is 1.6 mm 2 A crimped composite yarn was obtained in the same manner as in Example 1, except that the fluid injection pressure was changed to 0.45 MPa and the fluid injection pressure ratio before drawing and before winding was changed to 3.8.

[0082] There was a large amount of slack and fluff, yarn breakage occurred three times during weaving, which deteriorated processability, and the fabric had streak-like defects, resulting in poor fabric quality. Figure 8(b) shows the measurement results for Comparative Example 2. Compared to Example 5, there was a clear distinction between wide and narrow ranges, resulting in a yarn with uneven width.

[0083] (Comparative Example 3) The maximum cross-sectional area of ​​the interlace nozzle before drawing is 3.0 mm 2 A crimped composite yarn was obtained in the same manner as in Example 1, except that the increase rate of the yarn path cross-sectional area was changed to 0%.

[0084] There was a large amount of sagging and fuzz, thread breakage occurred four times during weaving, the processability was poor, and streaky defects were observed in the fabric, resulting in poor fabric quality.

[0085] Example 6 Nylon 610 (relative viscosity in sulfuric acid: 2.71, melting point: 226°C, specific gravity: 1.14) was used as the high-viscosity polymer component, and nylon 6 (relative viscosity in sulfuric acid: 2.63, melting point: 210°C, specific gravity: 1.14) was used as the low-viscosity polymer component. After melting at 270°C in an extruder, the mixture was pumped to a 22 dtex and fed into a conventional spinneret with 20 holes. The yarn discharged from the spinneret was cooled and solidified through a cooling device, then oiled in an oiling device and entangled in a first entanglement treatment device. The yarn was then taken up on a take-up roll at 2800 m / min, stretched 1.4 times, and heat-set at 155°C. The yarn was then entangled in a second entanglement treatment device, and a polyamide crimped composite yarn was obtained at a take-up speed of 3500 m / min. The interlacing and entanglement treatment conditions were the same as in Example 5.

[0086] The evaluation results of the obtained polyamide crimped composite yarn are shown in Table 1. Even with polyamide crimped composite yarns with small total fineness and single yarn fineness, the number of slacks and fluffs was low, and although yarn breakage occurred once during weaving, the processability was good and the fabric quality was also good.

[0087] Comparative Example 4 The maximum cross-sectional area of ​​the interlace nozzle before drawing is 3.0 mm 2 A crimped composite yarn was obtained in the same manner as in Example 6, except that the increase rate of the yarn path cross-sectional area was changed to 0%.

[0088] There was a large amount of sagging and fuzz, thread breakage occurred four times during weaving, the processability was poor, and streaky defects were observed in the fabric, resulting in poor fabric quality.

[0089] [Table 1] [Explanation of symbols]

[0090] 1: Crimped single yarn 2: Coil diameter 3: Coil mountain 4: Coil valley 5: Crimped yarn 6: Distance of the thread perpendicular to the longitudinal direction of the thread 7: Pre-stretching interlace nozzle 8: Yarn running axis 9:Fluid injection hole 10:Thread path 11: Yarn path (maximum cross-sectional area of ​​the yarn path) 12: Fluid injection hole angle 13: Pre-winding interlace nozzle 14: Spinneret 15: Heating body 16: Thread 17: Cooling device 18: Refueling equipment 19: First interlacing treatment device 20: First Godet Roller 21: Second Godet Roller 22: Second interlacing treatment device 23: Winder 24: Package stand 25: Tensioning means 26: Dimension measuring instrument 27: Yarn feed roller 28:Thread suction device

Claims

1. A crimped yarn made of a conjugated fiber having a coil diameter of 100 μm to 300 μm and a coil count of 1.0 / mm to 2.0 / mm, wherein the average distance in a direction perpendicular to the longitudinal direction of the yarn is 100 μm to 150 μm, and the difference between the maximum and minimum values ​​of the distance in the longitudinal direction of the yarn is 200 μm or less.

2. 2. The crimped yarn according to claim 1, wherein the CV% (coefficient of variation) of the distance in the direction perpendicular to the longitudinal direction of the yarn is 5% to 25%.

3. The crimped yarn according to claim 2, having a CF value of 10 to 30.

4. 4. The crimped yarn according to claim 1, wherein the single yarn fineness of the composite fiber is 0.5 dtex to 3.0 dtex.

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