JPH0610226A - Bulky elastic yarn and its production - Google Patents

Abstract

PURPOSE:To provide a covered elastic yarn capable of preventing MEMUKI which is a defect of a conventional covered elastic yarn even in an untwisted state, rich in bulkiness, and having a soft touch, a spun yarn-like appearance and a good elastic performance. CONSTITUTION:(1) The bulky elastic yarn is characterized by covering an elastic yarn with a crimped yarn (A) and a crimped yarn (B) having specific physical properties, respectively, blended and interlaced parts being partially imparted between the elastic yarn and the crimped yarn (A) and between the crimped yarn (A) and the crimped yarn (B), and by having a breaking elongation of 10-70%, a Young's modulus of <=800kg/mm<2>, and a crimp constant of 8-60%. (2) The method for producing the bulky elastic yarn is characterized by simultaneously blending and interlacing 5 an elastic yarn 1 in a unstretched state with at least two kinds of thermoplastic synthetic fibers (a) and (b) different in elongation therebetween and subsequently subjecting the blended and interlaced yarn to a false-twisting treatment 7, a thermal fixation 8 and an untwisting treatment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bulky elastic yarn obtained by coating an elastic yarn with at least two kinds of crimped yarns.

[0002]

2. Description of the Related Art Conventionally, a core span method, a covering method using a hollow spindle, and the like have been adopted as a method for producing a covered elastic yarn composed of an elastic yarn and a thermoplastic synthetic fiber. However, these methods have drawbacks such as low processing speed and difficulty in handling during knitting and weaving.

In order to improve such a defect, for example, Japanese Patent Publication No. 50-5305 discloses a method in which a stretched elastic yarn and a thermoplastic non-elastic fiber bundle are aligned and false twisted, and then relaxed. Japanese Patent Publication No. 60-20489 discloses a coated wound yarn rich in elasticity by mixing and interlacing polybutylene terephthalate and a polyester filament having a higher elongation than the filament, and then simultaneously drawing false twisting. Is disclosed. However, in all of these methods, the elastic yarn is coated with only one kind of thermoplastic fiber, and the coating is insufficient, so that stress is concentrated only on the elastic yarn when processing into a woven or knitted fabric. Threading and scoring of the elastic thread (a phenomenon in which the elastic thread jumps out due to cutting of the elastic thread, plastic deformation or displacement of the coated thread), which not only impairs the appearance of the product but also reduces elasticity. It has a fatal drawback that it may become unusable.

In Japanese Patent Publication No. 49-40017, a core yarn of an elastic yarn is falsely twisted with a yarn arranged so as to cover a sheath yarn of a thermoplastic synthetic fiber in a substantially parallel state. A method is disclosed in which another fiber yarn is supplied to the twisted region of the yarn and wound. However, in this method, since there is no mixed fiber / entanglement portion between the elastic yarn, the covering yarn, and the wrapping yarn, stress is still concentrated on the elastic yarn, and it is not possible to prevent the occurrence of eye blinding and the wrapping yarn is tight. Only tightly woven and knitted fabric with a tight texture can be obtained.

Further, these coated elastic yarns are generally twisted in order to improve the covering effect, but when twisted, the texture becomes hard and the quality when woven or knitted is improved. It also had the drawback of being damaged.

[0006]

DISCLOSURE OF THE INVENTION The object of the present invention is to prevent bulking, which is a drawback of conventional coated elastic yarns, and to have a high bulkiness, a soft texture and a span-like appearance. To provide the yarn.

[0007]

Means for Solving the Problems As a result of intensive studies for achieving the above object, the present inventors have found that when a bulky elastic yarn having a multi-step stress relaxation function described below is used, the elastic yarn is It has been clarified that a bulky elastic yarn which can prevent the eyes from peeling, has a high bulkiness, and has a soft hand and a span-like appearance can be obtained. Thus, according to the present invention, (1) the elastic yarn is coated with the crimped yarn (A) and the crimped yarn (B) having the following characteristics (a) to (d), in which case the elastic yarn and the crimped yarn are A mixed fiber / entanglement part is partially provided between the crimped yarn (A) and between the crimped yarn (A) and the crimped yarn (B), and the cutting elongation of the whole yarn is 10 ~ 70%, Young's modulus 800kg / mm ² or less,
A bulky elastic yarn having a crimp ratio of 8 to 60%. (B) The difference in the crimped yarn (B) from the crimped yarn (A) is 5%.
(B) The difference in cutting elongation of the crimped yarn (B) with respect to the crimped yarn (A) is 1
0% or more (C) Variation in cutting elongation of the single fibers that make up the crimped yarn (B) is 10% or more (D) Stress rate of the crimped yarn (B) is 70% or less, and (2) Tension state A method for producing a bulky elastic yarn, which comprises simultaneously mixing and entanglement of an elastic yarn of 1) and at least two or more kinds of thermoplastic synthetic fibers having a difference in elongation, and then false-twisting, heat-setting and untwisting the yarn. Provided.

The present invention will be described below with reference to the accompanying drawings. FIG. 1 is a side view showing an embodiment of the present invention. First, the elastic yarn 1 is applied to the first roller 2 and the second roller 3
After being stretched by a factor of 2 to 5 between them, the thermoplastic synthetic fibers a and b are supplied and entangled by the entanglement nozzle 5 provided between the second roller 3 and the third roller 4. Pneumatic pressure at this time is
1 to 6 kg / cm ² and an overfeed rate of 0.5 to 4% are suitable. By performing this entanglement treatment, it is possible to prevent the misalignment between yarns, and it is also possible to significantly reduce the number of yarn breakages during false twisting. The entangled yarn is simultaneously drawn and false twisted by using a heating plate 8 provided between the third roller 4 and the drawing roller 6 and a false twisting disk 7. The temperature of the heating plate may be appropriately set within a range that does not cause fusion or deterioration of the elastic yarn or the thermoplastic synthetic fiber a or b, and is preferably 100 to 200 ° C. The draw ratio may be appropriately set according to the elongation of the thermoplastic synthetic fiber used, but is preferably 1.1 to
1.9 times. The peripheral speed of the false twist disk 7 is preferably about twice the yarn speed. Then, the heat-set and untwisted entangled yarn is wound by a winder 9 to obtain a bulky elastic yarn 10.

The elastic yarn used in the present invention includes polyurethane yarn, rubber yarn, polybutylene terephthalate, block copolymer polyether-ester elastic yarn, and the like.
From the viewpoint of heat resistance and chemical resistance, it is preferable to use block copolymerized polyether-ester elastic yarn, which has an elongation of 200 to 900%. Further, pre-drawing of the elastic yarn can be omitted by adjusting spinning conditions and the like to reduce the elongation of the elastic yarn in advance.

The crimped yarns (A) and (B) are false-twisted crimped yarns composed of thermoplastic synthetic fiber multifilaments. For example, a semi-stretched yarn of polyester multifilament is shown in FIG. Simultaneous drawing false twisting may be performed by using a drawn yarn for b in FIG. At this time, the elongation difference between the thermoplastic synthetic fiber multifilaments needs to be 50% or more, and when this difference is 50% or less, a desired difference in yarn length between the crimped yarn (A) and the crimped yarn (B), It becomes difficult to give a difference in cutting elongation.

The above-mentioned thermoplastic synthetic fiber multifilaments may include modifiers, antioxidants, antitwisting agents, antistatic agents, optical brighteners, colorants, stabilizers, and inorganic materials as long as the object of the present invention is not impaired. You may add particles etc. Further, the thermoplastic synthetic fiber multifilaments may be spun from the same spinning cap. For example, when the raw yarn disclosed in Japanese Patent Publication No. 2-8043 is used, the raw yarn creel in false twisting is 1 This can be omitted and workability is improved.

It is necessary that the difference between the crimped yarn (B) and the crimped yarn (A) is 5% or more, and the difference in breaking elongation is 10% or more. If the difference in thread length is less than 5% or the difference in elongation at break is less than 10%, the multi-step stress relaxation function described later cannot be provided. However, if it is too large, it may cause thread misalignment and the like. Therefore, it is preferable that the difference in thread length is 100% or less and the difference in cutting elongation is 150% or less.

Further, the variation in cutting elongation of the crimped yarn (B) (shown by R in FIG. 2) must be 10% or more. When the variation is less than 10%, the stress of the crimped yarn (B) is too uniform and a soft and smooth stretch feeling cannot be obtained. However, if it is too large, single yarn breakage or the like will occur, so it is preferable to keep it below 100%.

Furthermore, the stress factor of the crimped yarn (B) is 70% or less,
It is preferably 50% or less. The stress rate is the ratio of the 10% elongation stress (shown as c in FIG. 2) to the cutting stress (shown as d in FIG. 2), and when this value exceeds 70%, soft stretching performance is obtained. I can't.

The crimped yarn (A) and the crimped yarn (B) having such characteristics are the spinning speed, the draw ratio and the draw temperature of the thermoplastic synthetic fiber multifilament, or the draw ratio in the simultaneous draw false twist. It can be obtained by appropriately adjusting the temperature of the heating plate, the peripheral speed of the false twist disc, and the like.

The bulky elastic yarn satisfying the above requirements of the present invention has a breaking elongation of 10 to 70%, preferably 20 to 60%.
If the elongation is less than 10%, cutting occurs before the elastic yarn stretching effect appears, while if it exceeds 70%, the elastic yarn is stressed too much and accelerates deterioration of the elastic yarn as well as restores it. The force may weaken and cause plastic deformation. Also,
The crimping ratio is 8 to 60%, preferably 20 to 45%, and if it is less than 8%, the stretching performance is impaired, while if it exceeds 60%, the elastic yarn is excessively stretched, which is not preferable. Furthermore, the Young's modulus is
It should be 800 kg / mm ² or less. If it exceeds 800 kg / mm ² , a strong force is required to expand and contract, and good expansion and contraction performance cannot be obtained.

[0017]

Since the present invention has the above-mentioned structure, it has the following effects. The bulky elastic yarn of the present invention includes an elastic yarn and a crimped yarn.
(A) and the crimped yarn (A) and the crimped yarn (B) have a mixed fiber / entangled portion, and the crimped yarn (A) and the crimped yarn (B) have an appropriate foot gap and Since it has a difference in elongation at break, it has a multi-step stress relaxation function and can prevent unfolding even in a non-twisted state, and can obtain a soft and smooth stretch property excellent in wearing feeling. That is, the multi-stage stress relaxation function means that when the bulky elastic yarn is stretched, the elastic yarn of the core is first stretched, then the stretching stress is transmitted to the crimped yarn (A), and the crimped yarn (A) is crimped. This is a function that enables the bulky elastic yarn as a whole to resist tensile stress, such that the crimp yarn (B) further expands while crimp resists tensile stress. Furthermore, since the crimped yarn (B) has physical properties that tend to cause stress dispersion, a soft and smooth stretch feeling can be imparted. On the other hand, in the conventional coated elastic yarn, the covering of the wound yarn is insufficient, and only the elastic yarn resists the tensile stress and is stretched more than necessary, so that the deterioration is accelerated and the wound yarn is not covered. The phenomenon occurs.

In other words, the multi-stage stress relaxation function of the bulky elastic yarn of the present invention is that the elastic yarn and the crimped yarn (A) and the crimped yarn (B) are mixed with each other in an appropriate amount.
Providing a entangled portion Providing a specific difference between the crimped yarn (A) and the crimped yarn (B) and a difference in cutting elongation. Providing the crimped yarn (B) with physical properties that tend to cause stress dispersion. It can be obtained only by simultaneously satisfying the three constituent requirements.

Furthermore, the bulky elastic yarn of the present invention is capable of maintaining a bulky and soft texture even after performing strong twisting. That is, since the crimped yarn (A) and the crimped yarn (B) are entangled in a state with a difference in thread length, there are many inter-fiber voids, and when such a yarn is twisted, Causes a so-called twist corrosion phenomenon in which the fibers in the outer peripheral portion are not twisted inside and remain in the outer peripheral portion as they are. Therefore, since the crimped yarn (B) on the outer peripheral portion can freely move as if there is no twist, it is possible to prevent the texture from becoming hard.

[0020]

EXAMPLES The present invention will be described in more detail below with reference to examples. In addition, each physical property in an Example is measured by the following method.

(1) Breaking elongation of bulky elastic yarn Using a tensile tester manufactured by Toyo Baldwin (type RTM-100), measurement was carried out under the conditions of a sample length of 200 mm and a pulling speed of 200 mm / min. Since the bulky elastic yarn of the present invention has a multi-stage stress relaxation function, breakage of constituent fibers occurs successively and the breaking point becomes unclear. Therefore, the elongation at the maximum stress point was defined as the breaking elongation. The measurement was performed 10 times and the average value was shown.

(2) Young's modulus of bulky elastic yarn Using a Toyo Baldwin tensile tester (type RTM-100), the load elongation curve recorded under the conditions of sample length 250 mm, pulling speed 50 mm / min, chart speed 200 mm / min. It was calculated from the maximum value of the initial tangent gradient of the above by a conventional method. The measurement was performed 10 times,
The average value is shown.

(3) Crimping rate of bulky elastic yarn The bulky elastic yarn is formed into a fold shape, a light load of 2 mg / denier is hung on this fold, and a heavy load of 0.2 g / denier is further hung and left for 1 minute. After the length of the ridge (l ₀ )
To read. Next, remove the heavy load, treat for 20 minutes in boiling water, remove it, remove the light load, and air dry for 24 hours. After air-drying, light and heavy loads are hung and left for 1 minute.
Read (l ₁ ). Next, remove the heavy load and set the length of the ridge (l ₂ )
To read. The crimp rate is calculated by the following formula. Crimp ratio (%) = (l ₁ −l ₂ ) / (l ₀ ) × 100 The measurement was carried out 5 times, and the average value was shown.

(4) Thread difference 50 cm of bulky elastic thread is taken out and a load of 0.2 g / denier is hung at one end of the thread. Then, at the middle of the thread, 1 at 5 cm intervals
Mark the points and cut out this part to make a sample. Ten single fibers of crimped yarn (A) and crimped yarn (B) are taken out from the sample, and the length thereof is measured by suspending a load of 1/30 g / denier. Assuming that the average lengths of the single fibers of the crimped yarn (A) and the crimped yarn (B) are l _A and l _B , respectively, the difference between the staple lengths is expressed by the following equation. Itoashi difference _{(%) = (l B -} l A) / l A × 100 The measurement was performed 10 times, expressed in the average value.

(5) Cutting elongation of crimped yarn Toyo Baldwin tensile tester (type UTM-II-20)
Using a sample length of 20 mm and a pulling speed of 200 mm / min, measurement is performed on 10 single fibers constituting the crimped yarn, and the elongation at the maximum stress point is taken as the cutting elongation to obtain the average value of 10 pieces. It was The measurement was performed 5 times and the average value was shown.

(6) Variation in cutting elongation of single fiber Toyo Baldwin tensile tester (type UTM-II-20)
With a sample length of 20 mm and a pulling speed of 200 mm / min.
10 pieces are measured, and the elongation at the maximum stress point is taken as the cutting elongation, and the difference (R in FIG. 2) between the maximum value (H in FIG. 2) and the minimum value (L in FIG. 2) among 10 pieces is obtained. It was The measurement was performed 5 times and the average value was shown.

(7) Stress rate of crimped yarn From the load stretching curve in the measurement of (6) above, the average value σ ₁₀ of stress at 10% elongation (c in FIG. 2) and the average value σ of cutting stress are
_B (d in FIG. 2) was obtained and calculated by the following formula. Stress rate (%) = σ ₁₀ / σ _B × 100 The measurement was performed 5 times and the average value was shown.

[0028]

Example 1 As the elastic yarn, a block copolymerized polyetherester unstretched monofilament (70 denier) having a breaking elongation of 800% and polybutylene terephthalate as a hard segment and polyoxybutylene glycol as a soft segment was used. As a crimped yarn, the cutting elongation is
135% polyester multifilament semi-drawn yarn (115 denier / 15 filaments) and breaking elongation of 33
0% polyester multifilament undrawn yarn (15
0 denier / 48 filaments) was fed to the apparatus shown in FIG.

First, the elastic yarn 1 is connected to the first roller 2 and the second roller.
After being stretched 4 times with La-3, it is aligned with the above-mentioned two types of polyester multifilaments on the upstream side of the second roller 3 and passed through an interlace nozzle 5 provided between the third roller 4 and a pneumatic pressure of 4 kg / cm ² , overfeed rate 2.5
% Of about 60 / m was added. Next, simultaneous drawing false twisting, heat setting, and untwisting are performed between the heating plate 8 provided between the third roller 4 and the stretching roller 6 and the false twisting disk 7, and then wound by the winder 9. Thus, bulky elastic yarn 10 was obtained. At this time, the draw ratio is 1.6 times, the temperature of the heating plate is 160 ° C, the peripheral speed of the false twist disc is 600 m / min, and the draw roller speed is 300.
It was m / min.

The bulky elastic yarn obtained had a breaking elongation of 35%, a Young's modulus of 300 kg / mm ² , and a crimp ratio of 35%. The crimped yarn (A) has a breaking elongation of 45% and the crimped yarn (B) has a breaking elongation of 70%.
% Difference of crimped yarn (B) to crimped yarn (A) is 30%,
The variation in cutting elongation was 45% and the stress rate was 38%.

This bulky elastic yarn is applied with S twist of 150 t / m,
After woven into a plain weave at a density of 100 warps / inch and weft 60 threads / inch, smelting, presetting, dyeing, and final setting were carried out according to the usual method. The resulting woven fabric had a soft, spun-like texture and appearance, and exhibited good stretchability. Further, as a result of observing the appearance of the woven fabric when stretched by 30% in each of warp and weft directions, no scoring was observed.

[0032]

[Example 2] Using the same elastic yarn as in Example 1, as a crimped yarn, a polyester multifilament drawn yarn (90 denier / 12 filament) having a breaking elongation of 80% and a polyester having a breaking elongation of 190% were used. A bulky elastic yarn 10 was obtained in the same manner as in Example 1 using a multifilament semi-drawn yarn (120 denier / 36 filament). At this time, the stretch ratio of the elastic yarn is 4 times, and the pneumatic pressure of the interlace nozzle is 5k.
g / mm ² , overfeed rate was 2%, simultaneous draw false twist ratio was 1.25 times, heating plate temperature was 200 ° C, false twist disc peripheral speed was 1400 m / min, draw roller speed was 700 m / min. .

The bulky elastic yarn obtained had a breaking elongation of 45%, a Young's modulus of 500 kg / mm ² , and a crimp ratio of 25%. The crimped yarn (A) has a breaking elongation of 35% and the crimped yarn (B) has a breaking elongation of 70%.
% Difference of crimped yarn (B) to crimped yarn (A) is 20%,
The variation in cutting elongation was 30% and the stress rate was 42%.

This bulky elastic yarn was subjected to 1500 t / m S-twist and woven into 2/2 twill with a density of 90 warps / inch and weft 55 threads / inch, and then refined and pretreated in the same manner as in Example 1. set,
Dyeing and final set were performed. The resulting fabric is
It had a soft and spun-like texture and appearance, and exhibited good stretchability. Further, as in the case of Example 1, even when the fabric was stretched by 30% in the warp direction and the weft direction, no scoring was observed.

[0035]

Comparative Example 1 The same elastic yarn as in Example 1 was used, but only one polyester multifilament semi-drawn yarn (225 denier / 36 filament) having a breaking elongation of 130% was used as the crimped yarn. A coated elastic yarn 10 was obtained in the same manner as in 1. At this time, the stretch ratio of the elastic yarn is 3 times, the compressed air pressure of the interlaced nozzle is 3 kg / mm ² , and the overfeed rate is 2
%, Simultaneous draw false twist ratio is 1.5 times, heating plate temperature is 150%
C., the peripheral speed of the false twist disc was 600 m / min, and the drawing roller speed was 300 m / min. The obtained coated elastic yarn had a breaking elongation of 30%, a Young's modulus of 900 kg / mm ² , and a crimp ratio of 10%.

This bulky elastic yarn is applied with S twist of 150 t / m,
After weaving into a plain weave at a density of 103 warps / inch and weft 63 threads / inch, refining, presetting, dyeing and final setting were carried out in the same manner as in Example 1. The resulting woven fabric was inferior in quality due to incomplete coverage of elastic yarn, and lacked smooth stretchability. Further, as in the case of Example 1, when a stretch of 30% was applied to each of the warp and weft directions of the woven fabric, the occurrence of the scouring was observed.

[0037]

According to the present invention, it is possible to prevent the elastic yarn from unfolding even in the untwisted state, and to have a high bulkiness even when the strong twisting is performed, to give a soft feeling, a span-like appearance and a good appearance. A bulky elastic yarn having stretchability is obtained.

[Brief description of drawings]

FIG. 1 is a side view of an apparatus for producing bulky elastic yarn according to the present invention.

FIG. 2 is a single fiber drawing curve of the crimped yarn that constitutes the bulky elastic yarn of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Elastic yarn 2 1st roller 3 2nd roller 4 3rd roller 5 Entangling nozzle 6 Drawing roller 7 False twist disk 8 Heating plate 9 Winding machine 10 Bulky elastic yarn a Thermoplastic synthetic fiber b Thermoplastic synthetic fiber c Single fiber Average value of 10% elongation stress d Average value of cutting stress of monofilament H Maximum value of cutting elongation of monofilament L Minimum value of cutting elongation of monofilament R Variation of cutting elongation of monofilament

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Claims (5)

[Claims] 1. An elastic yarn is covered with a crimped yarn (A) and a crimped yarn (B) having the following characteristics (a) to (d), in which case the elastic yarn and the crimped yarn (A) are covered. Between and crimped yarn (A) and crimped yarn (B)
A mixed fiber / entanglement part is partially provided between and, and the cutting elongation of the whole yarn is 10 to 70%, Young's modulus is 800 kg / mm.
A bulky elastic yarn having a crimp ratio of ² or less and 8 to 60%. (B) The difference in the crimped yarn (B) from the crimped yarn (A) is 5%.
(B) The difference in cutting elongation of the crimped yarn (B) with respect to the crimped yarn (A) is 1
0% or more (C) Variation in cutting elongation of the monofilaments constituting the crimped yarn (B) is 10% or more (d) Stress rate of the crimped yarn (B) is 70% or less 2. An elastic yarn in a tension state and at least two kinds of thermoplastic synthetic fibers having a difference in elongation are mixed at the same time.
A method for producing a bulky elastic yarn, which comprises false twisting, heat setting and untwisting after entanglement. 3. The method for producing a bulky elastic yarn according to claim 2, wherein the false twist is simultaneously drawn false twist. 4. The method for producing a bulky elastic yarn according to claim 3, wherein the thermoplastic synthetic fiber is a combination of a semi-stretched thermoplastic synthetic fiber and an unstretched thermoplastic synthetic fiber. 5. The thermoplastic synthetic fiber is a combination of a stretched thermoplastic synthetic fiber and a semi-stretched thermoplastic synthetic fiber.
A method for producing the bulky elastic yarn described.