JP4189288B2 - Special cross-section false twisted yarn manufacturing method - Google Patents

Description

The present invention relates to a method for producing a special section false twisted yarn. More specifically, it has a soft texture, and since it has little flat cross-sectional deformation, when it is made into a fabric, it can have a smooth dry feeling, water absorption, quick feeling, and has a draping texture. The present invention relates to a method for producing a special cross-section false-twisted yarn suitable for obtaining a fabric having both stretchability and elasticity.

It is well known that polytrimethylene terephthalate fibers have a low Young's modulus in terms of stretchability and that soft fibers can be obtained. However, in recent years, higher stretch properties have been required for fabrics made of fibers capable of expressing such bulkiness.
Conventionally, as a polyester fiber excellent in elastic recovery and suitable for a stretch material, for example, Patent Document 1 (Japanese Patent Laid-Open No. 11-93026) discloses a polyester false twisted yarn having polytrimethylene terephthalate as a main polymer component. Has been proposed. However, although the stretchability is excellent, the feeling of roughness due to crimping is strong, and the fabric lacks a soft texture.
Similarly, Patent Document 2 (Japanese Patent Laid-Open No. 2000-256925) proposes a polyester-based false twisted yarn in which polytrimethylene terephthalate is a main polymer component and is subjected to relaxation heat treatment continuously with a single-stage heater false twist. However, too much emphasis was placed on stretchability, and the fabric lacked a soft texture.
Patent Document 3 (Japanese Patent Laid-Open No. 2003-147649) also discloses a method for obtaining stretch properties using a side-by-side conjugate yarn in order to achieve these. However, in order to express the crimp of the conjugate yarn, it is necessary to make the restraining force acting on the conjugate yarn as small as possible. Therefore, the fabric structure must be loosened or the crimp is expressed. For this reason, there are characteristics such as that the fabric tends to be thick or that the crimps sag due to elongation and it is difficult to return to the original dimensions.
In Patent Document 4 (Japanese Patent Application Laid-Open No. 2003-82540), it exhibits a soft texture, and since flat cross-sectional deformation is small, when it is made into a fabric, it can maintain a smooth dry feeling, water absorption, quick drying, and Although a false twisted yarn having a draping property is disclosed, on the other hand, there is a drawback that the stretch property cannot be exhibited.

  In this way, with the conventional false twisting technology, workability (frequent yarn breakage), processed fluff occurs, and when the product is manufactured, the quality is lowered and the cross section is crushed, soft texture, water absorption The stretch property could not be expressed. In other words, with the conventional false twisting technology, the fabric has sufficient stretchability after false twisting so as to satisfy the sensitivity and functionality at the same time, and also has water absorption and quick drying properties. A polyester false twisted yarn and a method for producing the same have not been proposed so far.

JP-A-11-93026 JP 2000-256925 A JP 2003-147649 A JP 2003-82540 A

The present invention is a polyester false twisted yarn that has not been able to be produced until now, and the fabric has a sufficient stretch property and simultaneously exhibits water absorption and quick-drying properties. It had drape, and to provide a method for producing a polyester false twisted yarn of polytrimethylene terephthalate-based that may be expressed more woven or knitted fabric having excellent water absorption quick-drying simultaneously.

According to the present invention , an unstretched fiber comprising a polytrimethylene terephthalate-based polyester fiber and having a flat cross-sectional shape in which the cross-sectional shape of the fiber has two or more recesses on at least one side in the major axis direction is obtained by using a noncontact heater. Special cross-section false twisting, characterized in that, using a false twisting process equipped with a triaxial friction false twist type disk false twisting tool, the drawing simultaneous false twisting process is performed under the conditions satisfying the following (1) to (4) simultaneously: method for producing a yarn Ru are provided.
(1) The hardness of the urethane disk of the false twisting tool is 70 to 80 degrees (2) The false twist heater temperature is 100 to 300 ° C
(3) The draw ratio is 1.1 to 1.4 times (4) The number of false twists (times / m) is (10,000 to 25,000) / D ^1/2
(However, D indicates the fineness (dtex) of the false twisted yarn.)
The cross-sectional shape is as follows: (1) The cross-sectional shape of the fiber is a flat cross-sectional shape having two or more constrictions and a flatness of 2 to 7 (hereinafter also referred to as “cross-sectional shape (1)”). Alternatively, (2) a flat cross-sectional shape (hereinafter also referred to as “cross-sectional shape (2)”) having an opening angle of 100 to 150 degrees and a flatness of 2 to 4 in the cross-sectional shape of the fiber is preferable.
As the undrawn fibers used in the production method of the present invention, the polytrimethylene terephthalate polyester melt spinning, after heat treatment at 50 to 170 ° C., this wound in 2,000～4,000M / min The fibers obtained by taking are preferred.

  According to the present invention, it is possible to obtain stretch properties, and also has excellent drape and swell, eliminates stickiness and glare, and further exhibits excellent water absorption and quick drying properties in woven and knitted fabrics. Thus, it is possible to provide a special cross-section false twisted yarn made of polytrimethylene terephthalate-based polyester having a highly deformed fiber cross section that can simultaneously exhibit low air permeability.

The polytrimethylene terephthalate-based polyester used in the present invention is a polyester having a trimethylene terephthalate unit as a main repeating unit, and the polyester does not impair the object of the present invention, for example, 20 moles based on the acid component. % Or less, preferably 10 mol% or less, and other components may be copolymerized.
The copolymer component preferably used includes, for example, phthalic acid, isophthalic acid, 5-sodium sulfoisophthalic acid, adipic acid, sebacic acid and the like as the acid component, and butylene glycol as the glycol component. , Neopentyl glycol, bisphenol A, 2,2-bis {4- (β-hydroxyethoxy) phenyl} propane, and the like.

The intrinsic viscosity of the polyester used in the present invention (measured at 35 ° C. using orthochlorophenol as a solvent) is preferably from 0.60 to 1.20 dl / g from the viewpoint of yarn production.
In addition, the above-mentioned polyester has a known additive, for example, a pigment, a dye, a matting agent, an antifouling agent, a fluorescent brightening agent, a flame retardant, a stabilizer, and an ultraviolet absorber as long as the object of the present invention is not impaired. A lubricant or the like may be blended.

The special cross section false twisted yarn of the present invention is a false twisted yarn made of such polytrimethylene terephthalate polyester fiber.
In the present invention, it is necessary from the viewpoint of stretchability and elasticity that the filament yarn to be formed is a polytrimethylene terephthalate multifilament yarn.

In the special cross-section false twisted yarn of the present invention, first, the cross-sectional shape of the fiber is a flat cross-sectional shape having two or more concave portions on at least one side in the major axis direction.
As this cross-sectional shape, for example, (1) a flat cross-sectional shape having two or more constrictions (hereinafter sometimes referred to as a constricted portion) and a flatness of 2 to 7 [cross-sectional shape (1) Or a flat cross-sectional shape having a W-shape with an opening angle of 100 to 150 degrees and a flatness of 2 to 4 [cross-sectional shape (2)].

As the cross-sectional shape (1), it is necessary that the cross-sectional shape of the fiber has a constriction at two or more, preferably 3-5, and the flatness is 2-7, preferably 3-5. is there.
Here, the flatness refers to the maximum width (long axis) (A) of the cross section and the maximum width (B) of the short axis perpendicular to the long axis, as shown in FIG. Ratio (A / B), which is an average of 10 locations from the cross-section of the false twisted yarn. When the flatness is less than 2, it is difficult to form a collective form in which each single fiber spreads wide when it is made into a fabric, so that it is difficult to obtain sufficient anti-permeability and low air permeability. Not only that, but also recesses to be described later can be easily fitted to each other and water absorption is lowered, or bending resistance is increased and soft feeling is liable to be lowered. On the contrary, when the cross-sectional flatness exceeds 7, it is not preferable because the yarn-making property and false twisting are difficult.

  Here, the constricted portion of the present invention is a portion where the length of the short axis schematically shown in FIG. 1 is shortened. In such a constricted portion, the depth of the concave portion is 1.05 or more, preferably 1.1 or more, as a ratio (B / C) of the maximum width (B) to the minimum width (C) of the short axis. It is preferable from the viewpoint of water absorption and quick drying. If the depth is too large, the single fibers are easily separated in the fiber axis direction, so the ratio is preferably 3.0 or less, particularly 2.5 or less.

2A to 2C exemplify those in which the concave portion is formed so as to face both sides, but even if it is formed without facing both sides, only one side is formed. It may be formed. The number of the constricted portions needs to be two or more. If the number of constricted portions is one or less, the capillary phenomenon in the constricted portion becomes insufficient, and satisfactory water absorption cannot be obtained, which is not preferable. The number of constricted portions is not particularly limited as long as it is two or more, but 3 to 5 is appropriate in consideration of the yarn forming property.
2 (d) and 2 (e), the number of constricted portions is 1 or 6, and is out of the scope of the present invention.

On the other hand, the cross-sectional shape (2) is a flat cross-sectional shape having a W-shape with an opening angle of 100 to 150 degrees and a flatness of 2 to 4. Specific examples of the cross-sectional shape (2) include polytrimethylene terephthalate W cross-sectional yarn described in JP-A-2001-316943.
Here, the opening angle refers to an angle between tangent lines drawn in the lower concave portion of the W-shaped cross section as shown in FIG. Further, the flatness is a value obtained by drawing a rectangle circumscribing the W-shaped filament as shown in FIG. 3 and dividing the long side H by the short side L.

  In the filament having the cross-sectional shape (2), for example, when the false twisted yarn of the present invention is woven only when the flatness of the W-shaped cross section has this limited range, the warp in the woven fabric structure is formed. Each filament is regularly arranged in a certain direction. This is schematically shown in FIG. That is, most of the multifilaments overlap well with the unevenness of the W-shaped cross section, and are packed as close as possible in a “brick-stacked form”. Such a “brick stacking form” of the woven fabric does not collapse even after the subsequent scouring and dyeing finishing process, and is maintained until the final product. It is assumed that the filaments at the intersections of the woven fabric structure are closely packed and develop a soft texture by this characteristic structure. Moreover, since the bending stress of a multifilament falls and a crimp becomes large by this form, it is thought that stretch property expresses.

  The false twisted yarn having the cross-sectional shape (2), for example, is not clear why warp yarns in a woven fabric structure constitute a “brick pile”, but the warp tension during weaving and the loom of the loom It is presumed that the kinetic force coincided by chance to allow the rearrangement of the filaments in the multifilament. If the flatness is less than 2, the overlapping of the filaments does not become “brick-stacked”, and the texture becomes close to a conventional round cross section, and the object of the present invention is not achieved. On the other hand, if the flatness exceeds 4, the spinning stability becomes poor at the stage of spinning. The preferred flatness is in the range of 2-3.

  Moreover, in cross-sectional shape (2), it is necessary that the opening angle of each recessed part of a W-shaped cross section is 100 to 150 degrees. Preferably it is 110-140 degree | times. The opening angle means the sharpness of the cross-sectional shape. The smaller the angle, the sharper the cross-section, and the larger the angle, the dull. If the opening angle is less than 100 degrees or more than 150 degrees, it becomes difficult to form a “brick pile”, and the object of the present invention is not achieved.

Next, the special cross-section false twisted yarn of the present invention needs to have a crimp rate of 15 to 25%, preferably 18 to 23%. By having the crimp of this range, while maintaining stretchability, the obtained fabric exhibits a soft texture and suppresses a decrease in color tone due to conjugation spots. If the crimping ratio is less than 15%, the stretchability is insufficient, the inter-yarn gaps increase, the dye becomes easy to enter, and the dyed spots are easily expressed, which is not preferable. On the other hand, if it exceeds 25%, the surface of the resulting fabric tends to have a whitish tone, and a feeling of roughness is exhibited, which is not preferable. By setting it within this range, a knitted or knitted fabric having stretchability and excellent soft feel and at the same time having no color tone deterioration due to entanglement spots can be obtained.
The crimp rate can be easily adjusted by optimizing false twist conditions (temperature, magnification, false twist number).

Similarly, it is necessary for the special cross-section false twisted yarn of the present invention that the 10% stretch elastic recovery rate is 70% or more in order to maintain the stretch property. If it is less than 70%, the desired stretchability and elasticity cannot be obtained. Preferably, it is 75 to 95%.
The 10% stretch elastic recovery rate can be adjusted by optimizing the flatness of the cross-sectional shape and false twist conditions (temperature, magnification, false twist number).

  In addition, since the single fiber fineness of the special cross-section false twisted yarn of the present invention is too large, the texture tends to be hard, and conversely, if it is too small, the yarn forming property and false twist workability are liable to be reduced. A range of ˜5.0 dtex, particularly a range of 1.5 to 4.0 dtex is suitable.

The special cross-section false twisted yarn of the present invention described above can be manufactured, for example, by the following method.
That is, an unstretched fiber comprising a polytrimethylene terephthalate-based polyester fiber and a cross-sectional shape of the fiber having a flat cross-sectional shape having two or more recesses on at least one side in the major axis direction is obtained by using a non-contact heater and triaxial friction. What is necessary is just to carry out the extending | stretching simultaneous false twist process on the conditions which satisfy simultaneously the following (1)-(4) mentioned later using the false twist processing machine provided with the false twist type disk false twist tool.

  In general, it is thought that the reason why the skin feels uncomfortable is mainly due to the large contact area per unit fineness when touching the skin, but in the case of fibers with a high water retention rate, such as cotton fibers. Instead, it wets the skin surface and gives it a sticky feeling. On the other hand, in the false twisted yarn of the present invention, the surface in contact with the skin is always covered with flat fibers, and always feels dry and gives a dry feeling. The water retention of the false twisted yarn at this time is 60 to 90% in the appropriate region. When the water retention rate is less than 50%, the water absorption and quick drying properties are insufficient. On the other hand, when the water retention rate exceeds 90%, a sticky feeling is felt, which is not preferable.

Here, the production method of the undrawn fiber used for the production of the false twisted yarn of the present invention is not particularly limited, but the special cross-section false twisted yarn for the woven or knitted fabric of the present invention is, for example, by the following method. Can be manufactured.
That is, after the polymer is melted and discharged to cool the yarn group, the polytrimethylene terephthalate is heat treated at 50 to 170 ° C., and then the spinning speed is 2,000 to 4,000 m / min, particularly 2,500 to 3,500 m. Sink within the range of / min.
Here, heat treatment at 50 to 170 ° C. is an important point for stabilizing the appearance and quality against changes with time. If the temperature is less than 50 ° C, the object cannot be achieved. On the other hand, if the temperature exceeds 170 ° C, winding cannot be performed.
Further, when the spinning take-up speed is less than 2,000 m / min, the polyester fiber becomes brittle and yarn breakage occurs frequently during the drawing false twisting described later, which is not preferable. On the other hand, if it exceeds 4,000 m / min, fluff is likely to occur during the drawing false twisting, which is not preferable.

  Next, in the present invention, at the time of false twisting, the following (1) to (4) are simultaneously performed using a false twisting machine provided with a non-contact type false twisting heater and a triaxial friction false twisting type disk false twisting tool. It is necessary to perform satisfactory simultaneous simultaneous false twisting.

(1) At the time of simultaneous false twisting, it is important that the friction disk of the triaxial friction false twist type disk false twisting tool is a urethane disk and the hardness thereof is 70 to 80 degrees. The thickness is preferably 5 to 9 mm, and the traveling angle of the yarn is preferably 30 to 40 degrees with respect to the rotating shaft.
As a material of the friction disk of the triaxial friction false twist type disk false twist tool, it is necessary to use a urethane disk. In particular, when imparting false twist to polyester unstretched yarn of polytrimethylene terephthalate, it is excellent in twisting property, and since there is less decrease in the strength and elongation of processed yarn and generation of fluff, polyurethane or a modified product thereof is Preferably used.

In the present invention, the hardness of the friction disk needs to be in the range of 70 to 80 degrees, preferably 75 to 80 degrees. Therefore, in the present invention, a friction disk having a lower hardness and softer than a conventionally used friction disk is used. If the friction disk has a hardness of less than 70 degrees, the force to grip the running yarn is increased, but the friction disk is heavily worn, the service life is shortened, and breakage due to wear of the friction disk is likely to occur. This is inappropriate. On the other hand, when polytrimethylene terephthalate unstretched yarn is stretched and false twisted, the amorphous yarn is stretched and twisted while twisting at a high speed and at high magnification, so the hardness exceeds 80 degrees. For example, in a hard friction disk having a hardness of 85 degrees or more that is usually used, the yarn is damaged, and yarn breakage and fluff are likely to occur. Further, when the hardness of the friction disk is out of the above range, the crimping performance and the strong elongation of the processed yarn are lowered.
Here, the hardness of the friction disk is measured by the method of JIS K6301-1971.

The thickness of the friction disk is also related to the running angle of the yarn, and is preferably 5 to 9 mm, more preferably 7 to 9 mm in the present invention.
If the thickness is less than 5 mm, the twisting force is increased, but the yarn feeding force is reduced, so that high-speed processing becomes difficult. On the other hand, if the thickness exceeds 9 mm, the yarn feeding force is increased, but the untwisting tension is too low, the occurrence of yarn breakage and fluff is increased, and the thread catching property becomes difficult. The number of friction disks is preferably 4-9.

Moreover, in this invention, it is preferable to carry out contact driving | running | working with the running angle of a thread | yarn 30-40 degrees with respect to a rotating shaft.
Here, the traveling angle means an angle θ formed by the rotating shaft and the yarn traveling in contact on the outer periphery of the friction disk.

Furthermore, the twisting force is necessary for imparting sufficient crimping performance to the traveling yarn, and the yarn feeding force is indispensable for achieving a high processing speed. Usually, as the processing speed increases, the running condition of the yarn tends to become unstable, and it is necessary to increase the twisting tension (the tension on the entry side to the friction disk) to stabilize the running condition. Along with this, untwisting tension (tension on the exit side from the friction disk) inevitably increases. As a result, yarn breakage and fluff are likely to occur.
This tendency is particularly prominent as surging (yarn sway) when unstretched polytrimethylene terephthalate yarn is stretched as in the present invention, and there is also a concern about the problem of friction disk wear. It becomes.

  Therefore, in the present invention, the yarn running angle θ is preferably selected within the range of 30 to 40 degrees (more preferably 35 to 40 degrees), thereby increasing the yarn feeding action and reducing the untwisting tension. Thus, high-speed machining is possible without reducing the crimping performance of the processed yarn. When the running angle θ is less than 30 degrees, the twisting force is increased, but the yarn feeding force is decreased, and thus high-speed processing becomes difficult. On the other hand, when the running angle θ exceeds 40 degrees, the yarn feeding force increases, but the twisting force decreases, the crimping performance of the processed yarn decreases, the strength elongation decreases, and there are many occurrences of yarn breakage and fluff. This is inappropriate.

  In order to set the running angle θ within the range of 30 to 40 degrees, the diameter and thickness of the friction disks and the interval between the friction disks may be adjusted. The traveling angle θ needs to be set so as to be within the above range for all the friction disks, and for this purpose, it is convenient to use a guide disk.

In the present invention, the air entanglement treatment may be performed in a step different from the stretching false twisting process, but as shown in FIG. 5, an interlace nozzle is installed in the stretching false twisting apparatus and is performed immediately before the stretching false twisting process. Is preferred. This has a positive effect on the handleability, and furthermore, by applying air entanglement to the yarn after heat-set false twisting, the mixed fiber entanglement is perfectly uniformed and a texture that gives a sense of quality is expressed. It is.
If the degree of air entanglement is too small, the yarn surface will be separated during drawing false twisting, and the surface of the fabric will be uneven when woven or knitted, and the degree of entanglement measured with false twisted yarn is 15 / M or more, preferably 20 / m or more. On the other hand, if the degree of entanglement becomes too high, the entanglement between single yarns becomes too strong, and the texture when knitted or knitted is likely to be coarse, so 80 / m or less is preferable.

  Next, the unstretched polyester fiber is stretched and false twisted using, for example, a stretch false twisting machine equipped with a two-stage heater as shown in FIG. FIG. 5 shows a process of subjecting the unstretched polyester fiber (1) to an air entanglement treatment by an interlace nozzle (4) installed between two pairs of feed rollers (3, 3 ′). ing. The unstretched fibers entangled here are twisted by friction with the rotating false twisting disk (7) while being stretched between the feed roller (3 ') and the first delivery roller (8). Is done. In the meantime, it is heat-treated by the first stage heater (5), cooled by the cooling plate (6), passed through the false twist disk (7) and untwisted. Furthermore, the traveling yarn is reheated by a second stage heater (9) installed between the first deliberry roller (8) and the second deliberry roller (10), and more preferably, the heat set temporary After twisting the yarn, air entanglement (not shown) is performed, and then wound as a cheese-like package (12) by a winding roller (11).

  In the above-mentioned drawing false twisting machine, it is preferable that both the first stage heater (5) and the second stage heater (9) are non-contact type in consideration of drawing false twist processability at high speed. However, it is not necessary to use the second stage heater, but it is preferable to set the heat again with the second stage heater in consideration of the shrinkage rate (width filling rate) when it is made into a woven fabric.

Next, in the drawing false twisting process, drawing false twisting is performed under the conditions satisfying the following (2) to (4).
(2) The false twist first heater temperature is 100 to 300 ° C.
(3) Work stretch ratio: 1.1 to 1.4
(4) Number of false twists (times / m) is (10,000 to 25,000) / D ^1/2 [D is the fineness (dtex) of polyester false twisted yarn]

  Here, when the first heater temperature is less than 100 ° C., sufficient crimp cannot be imparted, and only a crimp rate of less than 15% can be obtained. On the other hand, when the temperature of the first heater exceeds 300 ° C., the deformation of the cross-sectional shape during false twisting becomes too severe, and there is no recess (necked portion), resulting in a decrease in water absorption as well as an average flatness. Since it becomes easy to exceed 7, it is not preferable. Furthermore, during the drawing false twisting process, fusion between single yarns is likely to occur partially, and only false twisted yarns that are rough and inferior in quality with a rough feel can be obtained. Also, the crimp rate tends to be too high.

  Also, with respect to the processing draw ratio: 1.1 to 1.4, if the draw ratio is less than 1.1, the twisting tension at the time of processing cannot be made uniform, and surging occurs and heat set spots are avoided. There is a need. On the other hand, if the draw ratio exceeds 1.4, the processed fluff tends to frequently occur, which is not preferable.

Next, when the number of false twists (times / m) is less than 10,000 / D ^1/2 , sufficient crimp cannot be imparted, and only those having a crimp rate of less than 15% are obtained. Disappear. On the other hand, when the number of false twists (times / m) exceeds 25,000 / D1 / ² , the single yarn is likely to be cut at the time of drawing false twisting, which is preferable because fluff and yarn breakage are likely to occur. Absent.

The first stage heater of the drawing false twisting machine may be divided into a first half and a second half, but in that case, for example, the first half and the second half are set at the same temperature. That's fine.
The heat treatment time of the yarn in the first stage heater may be set as appropriate depending on the type of heater, its length and its temperature, etc., but if it is too short, the crimping rate tends to be insufficient, and the tension may vary. The resulting stretched false twisted yarn, fuzz of false twisted yarn, and dyeing spots on the woven or knitted fabric tend to occur. Conversely, if the length is too long, the crimp rate tends to be too large. Therefore, in the case of a normal non-contact type heater, it is appropriate to set it in the range of 0.04 to 0.12 seconds, particularly in the range of 0.06 to 0.10 seconds.

Hereinafter, the present invention will be described in more detail with reference to examples. In addition, each item in an Example was measured with the following method.
In each table, “C3T” means polytrimethylene terephthalate, and “PET” means polytriethylene terephthalate. “Spinning speed” indicates the spinning take-up speed, “C3T-P0Y GR temperature ° C.” indicates the temperature (° C.) of the godet roller during melt spinning, and “Processing DR” indicates the draw ratio during draw false twisting.

(4) with 10% elongation elastic recovery Autograph, as shown in FIG. 7, by multiplying the initial load (1/30 dtex) to the sample, and removing the load to restore after elongation was up to 10% (L), After standing for 2 minutes, the film was again stretched to a certain elongation (L ₁ ), and the recovery rate was determined from the following formula.
Tensile elastic recovery rate (%) = [(L−L ₁ ) / L] × 100
(5) Young's modulus Measured according to JIS: L1013 (6) Cross-sectional flatness Unstretched polyester fiber or false twisted yarn was sampled at 10 locations every 10 m in the fiber axis direction, and a cross-sectional micrograph was taken. For the entire fiber cross-section, the maximum width A (long axis) of the cross-sectional shape and the maximum width B of the short axis perpendicular to the long axis are measured, A / B is calculated, and the average value of all measured values is the cross-section Flatness was assumed.

(7) Neck portion ratio Ten unstretched polyester fibers or false twisted yarns were sampled every 10 m in the fiber axis direction, and cross-sectional micrographs were taken. The ratio (B / C) of the short axis maximum width B to the minimum width C (width in the short axis direction of the recess) (B / C) of the entire cross section of the imaged fiber is defined as the constriction portion ratio.

(8) Method for measuring water retention rate After knitting a processed yarn and immersing a sample obtained by drying in water for 30 minutes or more, it is dehydrated for 5 minutes by a dehydrator of a domestic electric washing machine. From the weight of the dried sample and the weight of the sample after dehydration, it was determined by the following formula.
Water retention rate (%) = [(weight of sample after dehydration−weight of dried sample) / (weight of dried sample)] × 100

(9) Breathability Based on JIS L-1096-79-6.27 Breathability A method, it measured using the Frazier type air flow rate measuring device.
(10) Wicking property The wicking value (second) was measured with the sample fabric according to JISL1907-5.1.1 (drop method).
(11) Birec method water absorption performance According to JIS-L1018B, one end of a 2.5 cm wide fabric was immersed in water, and the height mm of the water sucked up after 10 minutes was measured.

(12) Traveling angle Photographing the yarn running on the false twisted disk, measuring the running angle θ of the yarn on each false twisted disk on the photograph, and averaging the measured values Was taken as the running angle.
(13) Entanglement degree: Applying a load of 0.2 cN / dtex to the end of a polyester false twisted yarn of about 1.2 m, pulling it perpendicularly from the fixing point attached to the upper part of the screen, 0.1 cN / dtex A fishhook hook having a weight corresponding to the load is used, the fishhook hook is inserted from the upper fixing point, and it is removed after the hook naturally falls and stops. The hook is then reinserted at a position 2 mm below the stop point. This repetition was performed over a length of 1 m, and the number of hooks stopped during that time was defined as the degree of entanglement (pieces / m).

(14) Number of stretched false twisted yarns Stretch false twisting was continuously carried out for 1 week with Teijin Seiki's 216-cage HTS-15V (2-heater false twisting machine, non-contact heater specification). The number of yarn breaks per unit / day was defined as a drawn false twist yarn. However, yarn breakage due to man-made or mechanical factors such as yarn breakage before and after yarn joining (knot breakage) or yarn breakage during automatic switching was excluded from the number of yarn breaks.

(15) Crimp rate A tension of 0.044 cN / dtex was applied to the false twisted yarn sample and wound around a cassette frame to produce a cassette of about 3,300 dtex. Two loads of 0.0177 cN / dtex and 0.177 cN / dtex were applied to one end of the cassette, and the length S0 (cm) after 1 minute was measured. Subsequently, it was treated in boiling water at 100 ° C. for 20 minutes with the load of 0.177 cN / dtex removed. Remove the load of 0.0177 cN / dtex after boiling water treatment, let it dry naturally for 24 hours, load 0.0177 cN / dtex and 0.177 cN / dtex again, and adjust the length after 1 minute. Measurement was made S1 (cm). Next, the load of 0.177 cN / dtex was removed, the length after 1 minute was measured and set to S2, and the crimp rate was calculated by the following formula, and expressed as the average value of 10 measurements.
Crimp rate (%) = [(S1-S2) / S0] × 100

(16) Strength and elongation of false twisted yarn Measured according to JIS L-1013-75.
(17) Number of fluffs Using a DT-104 type fluff counter device manufactured by Toray Industries, Inc., a polyester false twisted yarn sample was continuously measured at a speed of 500 m / min for 20 minutes, and the number of fluffs was measured. Expressed as the number per 10,000 m.

(18) Criteria for Evaluation of Textiles (Texture) Tube Knitting Stretch Texture Level 1: Extremely repulsive and stretchy.
Level 2: Stretch is poor, but resilience is felt.
Level 3: No elasticity or stretch feeling.
(Texture) Soft sensation Level 1: Soft and supple feel Level 2: Slightly soft feeling but repellent feel Level 3: Rough feel or hard touch (Texture) Drapability Level 1: Extremely draped It is large.
Level 2: Normal drape.
Level 3: Small drape.

(19) Stickiness (feel)
The resistance (dynamic friction coefficient) when sliding the fabric with water retained on the cowhide (numerical value for detecting the frictional force between the test fabric and the metal roller with a U gauge) is measured and evaluated as the degree of stickiness (g). (The higher the number, the greater the stickiness.)

Example 1
From a die having 36 discharge holes having a cross-sectional shape of polytrimethylene terephthalate having an intrinsic viscosity of 0.95 dl / g and containing 0.07% by weight of titanium oxide as shown in FIG. 1 and FIG. After melt discharge at 265 ° C., extrusion was performed at a discharge rate of 26.7 g / min, heat treatment was performed at 110 ° C., and then the undrawn yarn was wound at a spinning speed of 2,500 m / min, and the elongation was 100%. 110 dtex (100 d) / 36 fil of flat section undrawn yarn was obtained.
Stretching simultaneous false twisting was performed using the apparatus shown in FIG. 5 and a false twisting machine in which the false twist heat set heater is a non-contact type. At that time, the false twist draw ratio is 1.35 times, the false twist temperature 1H is 230 ° C., a triaxial friction disk is used as a false twister, twisting tension (K) 40 g (0.24 g / dtex), untwisting It was processed at a speed of 800 m / min with a tension of 30 g to obtain a stretch false twisted yarn of 83 dtex (75 d) / 36 fil. The obtained false twisted yarn had a crimp rate TC of 20% and a stretch property.

  When the obtained false twisted yarn was subjected to a twist of 2,000 turns / m in the direction opposite to the false twist direction, and a 10% elongation elastic recovery rate was obtained at a test length of 200 mm, it was surprisingly 90% The recovery rate was shown. Next, a fabric with a shoulder mat structure having a warp density of 118 yarns / inch and a weft density of 80 yarns / inch was produced using the false twisted yarn for the evaluation of stretch properties, and a 10% stretch elastic recovery rate was obtained. The recovery rate was 91% in the warp direction and 89% in the weft direction.

  The obtained false twisted yarn was knitted into a tubular knitted fabric, and the knitted fabric that was dyed and finished according to a conventional method had a smooth surface touch that was slatted, had stretchability, and exhibited a soft texture. . In addition, this false twisted yarn is subjected to a 1,800 T / m twisted yarn, woven into a twill structure with a warp density of 176 / 3.79 cm, and a weft density of 106 / 3.79 cm. Temperature 120 ° C, 20 minutes) Preset (temperature 180 ° C, 45 seconds), alkali weight loss treatment (weight loss rate 17%), dyeing (temperature 130 ° C, 45 minutes), and final set (temperature 160 ° C, 45 seconds) ) To obtain a woven fabric. The resulting woven fabric does not have a fluffy texture due to crimping like conventional false twisted yarn, has a feeling of elasticity, has no dyeing waste, has high quality, and exhibits excellent drape. It was an excellent fabric. The results are shown in Table 1.

Comparative Example 1
Polyethylene terephthalate is melted and discharged from a die having 36 discharge holes having the cross-sectional shape shown in FIGS. 1 and 2A at a die temperature of 265 ° C., and then spun at a spinning speed of 3,200 m / min. A highly oriented unstretched polyester filament having a degree of 125%, 138 dtex (125d) / 36 fil was obtained.
After the filament is mixed and entangled (number of entanglement: 50 / m), using a triaxial friction disk as a false twisting tool under a draw ratio of 1.63 and a false twisting temperature of 300 ° C., and twisting tension (T1) 45 g and 30 g of untwisting tension (T2) were processed at a speed of 800 m / min to obtain 83 dtex (75 d) / 36 fil false twisted yarn. The obtained false twisted yarn was subjected to a twist of 2,000 turns / m in the same manner as in Example 1, and a 10% elongation elastic recovery rate was obtained at a test length of 200 mm. As a result, it was 50% at most.

  When this false twisted yarn was processed into a woven fabric in the same manner as in Example 1, the 10% stretched elastic recovery rate was determined to be inferior levels of 53% in the warp direction and 57% in the weft direction. The obtained woven fabric was low in quality with no stretchability, no elasticity, and poor quality.

Examples 2-4, Comparative Examples 2-4
Under the conditions shown in Table 1, stretch false twisting was performed in the same manner as in Example 1.

Examples 5-7, Comparative Examples 5-7
Stretch false twisting was performed in the same manner as in Example 1 except that the cross-sectional shape was changed to the W shape, flatness, and opening angle shown in FIG. The results are shown in Table 2. In addition, the cross-sectional shape of the comparative example 6 is a round shape.

Examples 8-11, Comparative Examples 8-11
Except for changing the drawing false twisting conditions, drawing false twisting was performed in the same manner as in Example 1 under the conditions shown in Table 3. The results are shown in Table 3.

The polytrimethylene terephthalate false twisted yarn having a special cross-sectional shape according to the present invention is supplied to a conventionally known woven or knitted process, and is used for woven or knitted fabrics, preferably for woven fabrics. Therefore, the special cross-section false twisted yarn of the present invention can be woven stably without breaking if it is made into a plain fabric with a basis weight of 135 g / m ^{2 in} a water jet loom, for example, without twisting and without glue. After weaving or knitting, dyeing is performed to obtain a woven or knitted fabric having stretchability and a soft and good swell texture. In addition, if weaving using the special cross-section false twisted yarn of the present invention and dyeing, it has a high-class feeling effect with a very deep texture, and water absorption and quick drying performance, low air permeability, A functional woven fabric is obtained. Therefore, the special cross-section false twisted yarn of the present invention is particularly useful in the fields of stretchy garments that are actively supported, and that do not stick quickly by absorbing sweat and are suitable for women's suits and slacks.

It is a schematic diagram explaining the single yarn cross section of the special cross-section false twisted yarn of this invention. (A)-(c) is the schematic diagram of the single yarn cross section of the special section false twisted yarn of this invention, (d)-(e) is the schematic diagram of the single yarn cross section of the false twisted yarn of a comparative example. is there. It is a schematic diagram of the single yarn section of the special section false twisted yarn of the present invention. It is a mimetic diagram of each single yarn arrangement when weaving using the special section false twisted yarn of the present invention. It is the front view which showed one embodiment of the false twist disk unit used by this invention. It is a block diagram of the false twist tool used by this invention. It is a graph which shows the relationship between the expansion | extension of a thread | yarn, and stress.

Explanation of symbols

1: Polyester unstretched yarn 2: Thread guide 3, 3 ′: Feed roller 4: Interlace nozzle 5: First heater 6: Cooling plate 7: False twist disk unit 8: First delivery roller 9: Second heater 10: Second delivery roller 11: Winding roller 12: Polyester false twisted yarn cheese 13: False twist disk 14: Guide disk 15: Rotating shaft 16: Timing belt 17: Drive belt

Claims (4)

An unstretched fiber comprising a polytrimethylene terephthalate-based polyester fiber and having a flat cross-sectional shape in which the cross-sectional shape of the fiber has two or more recesses on at least one side in the major axis direction is made of a non-contact heater and triaxial friction false twist A method for producing a special cross-section false twisting yarn, characterized in that a false twisting machine equipped with a mold disk false twisting tool is used to simultaneously stretch and falsely twist under the conditions satisfying the following (1) to (4).
(1) The hardness of the urethane disk of the false twisting tool is 70 to 80 degrees (2) The false twist heater temperature is 100 to 300 ° C
(3) The draw ratio is 1.1 to 1.4
(4) Number of false twists (times / m) is (10,000 to 25,000) / D ^1/2
(However, D indicates the fineness (dtex) of the false twisted yarn.) Cross-sectional shape is, have two or more constricted, special sectional false twisted yarn manufacturing method of the flat degree according to claim 1, which is a 2-7 flat cross-sectional shape. Cross-sectional shape is, at the opening angle is 100 to 150 degrees W-shaped, profile cross section false twisted yarn manufacturing method of the flat degree claim 1, wherein is 2-4 flat cross-sectional shape. Undrawn fibers, and melt spinning the polytrimethylene terephthalate-based polyester after heat treatment at 50 to 170 ° C., according to claim 1 which is a fiber obtained by taking wound in 2,000～4,000M / min 4. A method for producing a special cross-section false twisted yarn according to any one of 3 above.

Images