JP2003342842A - High-functional fiber crimpled yarn, method for producing the same and fiber product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crimpled yarn of a high-functional fiber having slight reduction in strengths and excellent stretchability. <P>SOLUTION: The method for producing the crimpled finished yarn of the high-functional fiber comprises forming a knitted fabric using a high-functional fiber yarn having ≤20% water content, heat-treating the knitted fabric and unknitting the knitted fabric. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a crimped yarn of highly functional fiber such as aramid fiber having excellent heat resistance and durability, and a method for producing the crimped yarn.

[0002]

2. Description of the Related Art High-performance fibers such as aramid fibers are excellent in heat resistance and durability and are used for clothing products and the like in environments exposed to high heat, fire and scratches.

[0003] Conventionally, when high-performance fibers are used to manufacture clothing products, the fibers have been applied in the form of crimp-free raw yarn or spun yarn. As a result, when worn as a product for clothing, it is uncomfortable to wear, and it is difficult to work, especially in work clothes such as uniforms. In addition, in the use of work gloves used in the aircraft industry, information equipment industry, precision machinery industry, medical field, etc. that handle precision parts, using filament yarn reduces workability due to uncomfortable feeling to wear and lack of fit. In addition, there is a problem that fluff is generated when using spun yarn.

In view of the demands of the market, research and development have been conducted on a method for rationally providing crimps by using high-performance fibers as filaments.

For example, in Japanese Patent Laid-Open No. 6-280120, an aramid fiber yarn is decomposed at a temperature above its decomposition temperature and below its decomposition temperature (in the case of meta-aramid fiber, it is 390 ° C. or higher and 460 ° C. or higher).
There has been proposed a method for producing an aramid-based crimped yarn, which is characterized by performing false twist crimping using a non-contact heater heated to a temperature of less than 0 ° C.) and then performing relaxation heat treatment. However, in this method, since a strong twisting deformation is given in the false twisting process, the decrease in strength becomes large, and thus the durability is likely to decrease,
Furthermore, there are problems such as poor processability and deterioration of the surface quality of the product due to the false twist residual torque.

[0006] Further, in Japanese Patent Laid-Open No. 2001-248027, a crimped yarn is produced by a so-called knit / denit, in which a knitted fabric made by using a heat-resistant and high-performance fiber yarn is subjected to dry heat treatment or high-temperature heat-moisture treatment and then unknitted. A method has been proposed.
However, in this knit / denit, there are problems that the loop fixing property of the knitted fabric is low, and it is apt to be insufficiently crimped, and further fibrillation, fluffing and strength reduction are caused.

[0007]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a crimped yarn of a high-performance fiber which is excellent in stretchability with less reduction in strength and a method for producing the crimped yarn.

[0008]

That is, the present invention is a high-performance fiber crimped yarn having corrugated crimps and having a residual torque twist number of substantially zero.

Further, according to the present invention, a knitted fabric is prepared by using a yarn of a high-performance fiber having a moisture content of 20% or less, the knitted fabric is subjected to a heat treatment, and then the knitted fabric is unknitted. It is a method for producing crimped yarn.

Further, the present invention is a fiber product using the above-mentioned crimped high-performance fiber.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The high-performance fiber used in the present invention has excellent heat resistance and durability.

For example, aramid fibers include meta-aramid fibers and para-aramid fibers. Examples of the meta-aramid fibers include meta-type wholly aromatic polyamide fibers such as polymetaphenylene isophthalamide fibers (Dupont "Nomex"). Para-aramid fibers include para-aromatic polyamides such as polyparaphenylene terephthalamide fiber (Toray DuPont "Kevlar") and copolyparaphenylene-3,4'-diphenyl ether terephthalamide fiber (Teijin "Technora"). Fibers.

In addition to aramid fibers, there may be mentioned wholly aromatic polyester fibers (Kuraray "Vectran" etc.), polyparaphenylene benzobisoxazole fibers (Toyobo "Zylon" etc.), polybenzimidazole fibers, polyimide fibers and the like.

FIG. 1 shows a yarn form model of the high-performance crimped yarn of the present invention. Each single fiber has a corrugated crimp.
Preferably, the crimp phases are substantially the same in the multifilament, and a straight yarn is formed when the tension is applied, but when the tension is released, the yarn recovers as shown in FIG. 1 and thus has elasticity. Due to this crimped form,
The woven or knitted textile product can have a high surface quality.

The crimping phase is preferably almost uniform in the multifilament, but may be slightly deviated when subjected to entanglement treatment or the like.

The number of filaments constituting the yarn is preferably 200 to 800, more preferably 40.
It is 0-700. When the number of filaments increases, the texture of the knitted fabric product becomes softer and the bulkiness increases, but snagging tends to occur, so it is preferable to impart a converging property. Further, if the number of filaments is too small, the rigidity tends to be high, the texture of the product tends to be hard, and the bulkiness tends to be low, which tends to cause a cold sensation.

The total fineness of the yarn is 100 to 1500 d
Although it is preferably applied in the range of tex, the fineness and the number of filaments can be appropriately designed depending on the application. For example, in applications such as gloves, the fineness is 700 to 9
00 dtex, and the number of filaments is preferably 500 to 600.

The corrugated crimp of the highly functional crimped yarn of the present invention has a crimp length of 2 to 7 mm.

The crimp length can be obtained as follows. The length of the crimped yarn is fixed with a load of 0.002 cN / dtex applied, and the yarn shape is photographed with a universal projector.
As shown in FIG. 1, the yarn lengths from the convex portion (a) of the corrugated crimp to the convex portion (b) (a to c in the arrow direction and c to in the arrow direction).
b) is measured, and the total length {(a to c) + (c to
The average value L is calculated by measuring 10 times with 1/2 of b)} as the crimp length. When the crimp length is short, the bulkiness and stretchability are increased, and a knitted or woven product having a soft texture tends to be obtained. Further, when the crimp length is long, the bulkiness and the elasticity are lowered, and the knitted or woven product having a texture like a filament yarn tends to be obtained. The more preferable crimp length is 2 to 5 mm in the case of 100 to 300 dtex depending on the fineness of the crimped yarn.
However, in the case of 300 to 600 dtex, the range of 3 to 7 mm, and in the case of 600 to 1500 dtex, the range of 5 to 7 mm is more preferable.

The expansion and contraction rate of the highly functional crimped yarn of the present invention is preferably 1 to 10%. By setting the expansion / contraction elongation ratio to 1% or more, it can be used for applications requiring elasticity. By setting the expansion / contraction rate to 10% or less, it is possible to suppress a feeling of tightening and poor dimensional stability in the product.

The high performance fiber crimped yarn of the present invention has a residual torque twist number of substantially zero. Substantially 0 means that there is no torque due to the twisting and false twisting steps, and untwisting after winding on cheese etc. is not considered. In addition, there may be a real twist for imparting convergence as described later. By the residual torque twist number being substantially 0,
It is possible to solve problems such as poor processability and deterioration of the surface quality of the product.

The number of residual torque twists can be measured by the method described later in Examples.

Next, a method for manufacturing the high-performance crimped yarn of the present invention will be described.

The method for producing the high-performance fiber crimped yarn of the present invention comprises:
The present invention relates to a so-called knit / denit in which a knitted fabric is created by using yarns, crimps are formed, and the crimps are unknitted.
By providing the crimp with the knit / denit, it is possible to prevent deterioration of durability due to twisting deformation such as false twisting, poor processability due to residual torque, and deterioration of surface quality of the product.

In the method for producing a high-performance fiber crimped yarn of the present invention, it is important to use a high-performance fiber having a water content of 20% or less, preferably 10% or less, as the high-performance fiber to be used for producing the knitted fabric. is there. By doing so, crimps can be obtained sufficiently, and the knitting of conventional high-performance fibers
Denit can eliminate the problem of fibrillation and fluffing.

The moisture content is based on JIS L1013 "equilibrium moisture content".

As the knitting structure, a flat structure knitted fabric is preferable from the viewpoint of the passing property in the unknitting process and the uniformity of loops.

The crimp length can be roughly adjusted by the number of gauges of the knitting machine. The larger the number of gauges, the shorter the crimp length, and the smaller the number of gauges, the longer the crimp length. For example, the fineness of the highly functional fiber crimped yarn is 100 to 2
16 to 30G is applied as a gauge of the cylinder knitting machine at 00 dtex, and 12 to 26 G at 200 to 400 dtex.
However, 8 to 22 G is preferably applied at 400 dtex or more.

The crimp length can be further finely adjusted by the number of pulling stitches. The number of draw stitches is the number of loops formed by a knitting needle in forming a knitted fabric. When the number of loops knitted by the knitting needle is small, the loop length is long, and when the number of loops is large, the loop length is short.

Next, the knitted fabric is heat-treated to fix the loop shape. It is preferable to perform moist heat treatment. 105-2
1 to 12 with 50 ℃ high temperature high pressure water or high temperature high pressure steam
Treatment for 0 minutes is preferred. The higher the temperature, the easier it is to fix the loop shape, but at 200 ° C. or higher, the strength tends to decrease, so it may be appropriately changed depending on the application.

When the heat treatment applied to the knitted fabric is a wet heat treatment, it is preferable to perform a dehydration treatment after the wet heat treatment in order to securely fix the loop shape. It is considered that the mechanism of fixing the loop shape by the dehydration treatment is to re-bond the hydrogen bond in the fiber molecule by evaporating the water to bring it into an absolutely dry state. After the hydrogen bond, even if the moisture content in the air is absorbed and the moisture content becomes high, the crimp fixing property of the once-bonded part is not restored to the original property.

As a means for dehydration treatment, dry heat high temperature treatment, infrared / far infrared treatment, high frequency heating treatment, electromagnetic wave treatment and the like are particularly suitable.

As for the degree of absolute drying, it is preferable to treat the moisture content to 5% or less in a short time as much as possible. For that purpose, it is desirable to treat with high temperature or high power electromagnetic wave as far as possible. The specific treatment condition is 1 at dry heat temperature.
The range of 1 minute to 120 minutes at 50 ° C. to 600 ° C. is preferable, but the temperature and time can be appropriately changed depending on the application.

As an example of the dehydration treatment, it is preferable that the knitted fabric is put in a net or placed on a wire net and is treated in a relaxed state. It is preferable to avoid it because the end of the knitted fabric may be weakened or the dyeing may be abnormal if the fabric is strained or rolled.

After fixing the loop shape by heat treatment or the like, the knitted fabric is unknitted. Although the end portion where the knitting is started may be from either the beginning or the end of knitting, it is more preferable that the knitting is started from the end of knitting because less yarn breakage occurs.

The unwound yarn may be wound up with a corn winder or a cheese winder. At this time, if the winding tension is too high, the crimps are likely to disappear, so it is preferable to wind the winding as low as possible. Specifically, the fineness is 10 cN (10 gf) or less at 200 to 400 dtex, and 20 cN (20 g at 400 to 1000 dtex).
f) The following are preferred winding tensions.

In order to improve the passability of the unknitted crimped yarn in the knitting and weaving process, entanglement treatment may be performed after the unknitting or real twist may be added.

In addition, the high-performance fiber crimped yarns of the present invention may be processed into twin yarns, other synthetic fibers such as polyester and nylon, chemical fibers such as acetate and rayon, or natural fibers such as wool, cotton and silk. You may give mixed fiber processing. The mixed fiber processing method can be carried out by entanglement treatment, ply twist, or design twist yarn.

Next, the fiber product of the present invention comprises the high-performance crimped yarn of the present invention as described above. Its main uses are high-performance fibers such as heat resistance, durability, and cut resistance, but they also have soft texture and elasticity, so work gloves for aircraft, Self-Defense Force clothing, firefighting, etc. It is suitable for special work clothes such as clothes, safety work clothes for construction, and protective clothes for police, and sports clothes for patchwork usage.

Further, since it has elasticity, it has high passability in the weaving process, is less likely to cause fluffing and fibrillation, and can be used also as a warp yarn of a woven fabric. It can also be used as

Further, it is possible to obtain a surface having a rich satin finish. Therefore, applying a coating such as resin processing is also a preferable method in terms of the anchor effect and the like.

[0042]

[Examples] (Measurement / Evaluation Methods) (1) Cut wound resistance (difficulty in cutting) It was carried out as follows in accordance with ISO 13997: 1999. When the blade penetrates (cuts) the test piece with a certain movement distance, a heavier load is required for a material that is harder to cut. With the load L applied to the blade, when the blade penetrates the test piece at a moving distance of 20 mm, the load L is taken as the cut resistance value. The blade is A
american Safety Razor Co. ,
Part number No. 88-0121 was used. The measured value is expressed in N (newton) as a unit, and the larger the value is, the more difficult it is to cut.

(2) Apparent fineness Determined as an apparent fineness with a water content of 4.5% according to JIS 1090.

(3) Residual torque twist number When a load of 0.1 cN / dtex was applied to a sample, a small load of 0.4 cN was hung on the center of a test length of 1 m, and both ends of the sample were moved to the center. The number of rotations T of the small load is read by the twisting machine, and the number of rotations T per 50 cm is taken as the residual torque twist number.

(4) Product characteristics Each was evaluated as follows. Soft texture Soft (○) ~ (×) Hard Strong fit (○) to (×) weak Easy to move Easy (○) to (×) difficult Product surface quality is high (○) to (x) low Moreover, between the circles and the crosses was marked as Δ.

Example 1 Polyparaphenylene terephthalate manufactured by Toray-Dupont Co., Ltd. having a thermal decomposition point of 537 ° C., a tensile breaking strength of 21.2 cN / dtex, a fineness of 440 dtex, a filament number of 267 and a moisture content of 7.5%. Two amide (PPTA) fiber filament yarns (“Kevlar”) were drawn and aligned with 880 dtex, and a 16G cylinder knitting machine (manufactured by Koike Machinery Co., Ltd.) released a yarn at a speed of 100 m / min and a tube tension of 2 to 3 cN (2 to 3 gf). 10 m of knitted fabric was created.
Put the tubular knitted fabric in the dyeing net and use a high-temperature and high-pressure dyeing machine 1
A treatment in a bath at 35 ° C. for 15 minutes was performed. In this case, water alone was used and no activator was used.

Dehydration was carried out in advance by a stretching dehydrator, and subsequently dehydration processing was carried out at 250 ° C. for 45 minutes by a dry heat high temperature dryer.

After that, the tubular knitted fabric is unknitted from the knitting end direction, and while being applied with a finishing oil agent for knitting (Brian / Takemoto Yushi Co., Ltd.), it is wound into a cone with a cone winding machine, and the high-performance fiber crimp of the present invention is crimped. I got a thread. No fluffing or fibrillation was observed.

Further, working gloves were obtained from the crimped yarn as a fiber product of the present invention with a 10G glove knitting machine (manufactured by Shima Seiki Co., Ltd.). The process passability was good, and the gloves were comfortable to wear and easy to operate.

Table 1 shows the yarn characteristics of the obtained high-performance fiber crimped yarn and the physical properties of working gloves.

The work gloves weighed 435 g / m ² ,
The cut resistance indicating the difficulty of cutting was 8.8 N.

(Comparative Example 1) PP by knit / denit
Instead of the TA crimped yarn, a yarn having a fineness of 165 dtex and a number of filaments of 48 commercially available polyester filament crimped yarns aligned and totaling 990 dtex was used. Created. The wound resistance was 3.1N.

(Comparative Example 2) Thermal decomposition point 537 ° C., tensile breaking strength 21.7 cN / dtex, fineness 440 dtex,
Toray with 267 filaments and a moisture content of 38.8%
DuPont KK Polyparaphenylene terephthalamide (PPTA) fiber filament yarn ("Kevlar")
A knit / denit crimped yarn was prepared in the same manner as in Example 1 with two of them aligned and 880 dtex, but the quality was low because of fibrillation and fluffing, and further yarn breakage occurred.

(Comparative Example 3) Using the same raw yarn as in Comparative Example 2, the raw yarn was supplemented with an oil agent for knitting (Brian / Takemoto Yushi Co., Ltd.), and thereafter knitted under the same conditions as in Comparative Example 2. -A denit crimped yarn was prepared, but it was deflated with many fluffs and was of low quality.

[0055]

[Table 1]

[0056]

EFFECTS OF THE INVENTION According to the present invention, it is possible to obtain crimped yarns having high strength and excellent heat resistance, flame retardancy and the like, with little reduction in strength.

As for the strength maintenance ratio, elasticity can be imparted while maintaining a high strength of 70% or more as compared with the original yarn before crimping.

Further, since the high-performance fiber crimped yarn of the present invention has a residual torque twist number of substantially 0, when it is formed into a tubular knitting, skewing due to torque does not occur and the knitting is unknitted. The goodness and unwindability from the corn are good, and process troubles hardly occur.

[Brief description of drawings]

FIG. 1 is a model diagram of a yarn form example of a highly functional fiber crimped yarn of the present invention.

Claims (6)

[Claims] 1. A high-performance fiber crimped yarn having corrugated crimps and having a residual torque twist number of substantially zero. 2. The high-performance fiber crimped yarn according to claim 1, wherein the crimp length of the corrugated crimp is 2 to 7 mm. 3. A high-performance fiber crimped yarn for forming a knitted fabric using a yarn of high-performance fiber having a moisture content of 20% or less, heat-treating the knitted fabric, and then unknitting the knitted fabric. Manufacturing method. 4. The method for producing a highly functional crimped yarn according to claim 3, wherein the heat treatment applied to the knitted fabric is a wet heat treatment, and after the wet heat treatment, a dehydration treatment is performed and then the knitted fabric is unknitted. 5. The dry heat treatment temperature in the dehydration treatment is set to 150.
The method for producing a high-performance fiber crimped yarn according to claim 4, wherein the temperature is ˜600 ° C. 6. A fiber product comprising the high-performance fiber crimped yarn according to claim 1 or 2.