CN1326519A - Two-way warp knitted fabric - Google Patents

Abstract

A bidirectional warp knitted fabric is a knitted fabric with warp knitting structure formed by interweaving polytrimethylene terephthalate fibers on the front side and elastic fibers on the back side. The density ratio of the knitted fabric expressed by the following formula is 1.55-2.35. A knitted fabric density ratio = (number of courses/2.54 cm)/(number of wales/2.54 cm), (1) this knitted fabric is a knitted fabric which can suppress curling, has a soft texture, does not turn yellow, and is suitable for stretch properties for clothing.

Description

Two-way warp knitted fabric

technical field

The present invention relates to a warp knitted fabric exhibiting elasticity in two directions.

Background technique

The elongation direction of elastic fabric (knitted fabric) exists in the warp direction and weft direction, which is called two-way elastic fabric (knitted fabric) (see "Fiber Handbook" [2nd Edition: Textile Society: Maruzen Co., Ltd. Heisei 7 February Published on the 15th] pages 139-140, table 1.74 on page 139, see Japan Textile Management Association "Basic Knowledge of Fiber Products" Japan Clothing Management Association, pages 41-49 [1985]) warp knitted fabric interwoven with elastic yarn Generally known as two-way warp knitted fabrics. Nylon fibers are interwoven with elastic fibers, and elastic yarns form knitted loops for the following products: shorts for underwear, women's underwear, garters, bras, swimsuits for sports, skating and skiing suits, and elastic for diving. Diving suits, cycling shorts, coatings for outerwear, laminated jackets, etc. The elongation in the warp and weft directions of the generally used bidirectional warp knitted fabrics is: 100-300% in the warp direction and 50-200% in the weft direction.

The warp knitted fabric interwoven with nylon elastic yarn has the unique disadvantages of nylon fiber. The heat setting process in the dyeing process or the action of NOX gas during product storage can easily cause the fabric to turn yellow. Due to the use of acid dyes, discoloration caused by chlorine-containing water will occur. Phenomenon. In order to prevent these shortcomings, some adopt the method of low-temperature heat setting, and some adopt the method of completely sealing the package in order to prevent the final product from turning yellow, and some use fixatives to prevent discoloration caused by chlorinated water. The processing and finishing of products is very cumbersome.

In order to avoid the use of nylon fibers that are prone to yellowing and discoloration when exposed to chlorinated water, a two-way warp knitted fabric interwoven with polyethylene terephthalate fibers and elastic fibers has also been tried. However, when polyethylene terephthalate fiber is used, although the yellowing of the fiber can be avoided, the unique soft style of nylon fiber is also lost, and the style becomes hard. In order to obtain a soft fabric, loose knitting is adopted, and the finishing density is also loose, but there is a disadvantage of curling, and a soft fabric cannot be obtained.

It is well known that polyester fibers with low Young's modulus do not have the same yellowing problem as polyethylene terephthalate fibers.

Bielastic warp knitted fabrics made of polytrimethylene terephthalate fibers are particularly prone to knitted fabric defects in which the ends of the knitted fabric are curled (curled). The appearance of curling will reduce the processing efficiency during sewing, and sometimes it cannot be processed. This crimp is generated when the rigidity of the woven fiber returns the deformation that occurred during the formation of the loop to a stable state on the single surface of the warp knitted fabric when the expansion and contraction balance of the needle loop and the sinker loop is destroyed. In order to remove the curl The edge phenomenon can be greatly improved by using the density of knitted fabrics, but it will make the style harder and less elastic. In addition, there are other methods to control the stability of the fiber by heat setting at about 180°C by utilizing the thermal properties of the fiber. However, when the heat setting of the polytrimethylene terephthalate fiber is insufficient, the setting at a high temperature above 180°C will destroy the expansion and contraction balance, and curling will appear.

Overview of the invention

The object of the present invention is to provide bidirectional warp knitted fabrics. The bidirectional warp-knitted fabric solves the above-mentioned problems, does not turn yellow, has a soft style, and can substantially suppress the curling phenomenon by simple means.

The method realized by the present invention is to limit the ratio of the number of courses and the number of wales of the warp knitted fabric in which polyester fibers of polytrimethylene terephthalate and elastic fibers are interwoven to a specific range.

The bidirectional warp-knitted fabric of the present invention is characterized by a warp-knitted structure formed by interweaving polytrimethylene terephthalate fiber filaments on the front side and elastic fiber filaments on the back side. The warp knitted fabric represented by the following formula (1) has a density ratio of 1.55 to 2.35.

The present invention is further described in detail below.

The polytrimethylene terephthalate fiber in the present invention is the polyester fiber that is the main repeating unit of trimethylene terephthalate. The content of the propylene glycol terephthalate unit is about 50 mol % or more, preferably 70 mol % or more, more preferably 80 mol % or more, and more preferably 90 mol % or more. The remaining other components, the total amount of the acid component and/or diol component mentioned later is about 50 mole % or less, preferably 30 mole % or less, more preferably 20 mole % or less, and more preferably 10 mole % or less.

The shape of polypropylene terephthalate fiber can be long fiber or short fiber, even and uneven in the length direction, and the cross section can be circular, triangular, L-shaped, T-shaped, Y-shaped, W-shaped, eight-lobed, Flat type, dumbbell-shaped polygonal type, multi-leaf type, hollow type, indeterminate shape, etc. When making underwear, sportswear or outerwear, it is best to use long fibers, fibers with special-shaped cross-sections such as triangles with uniform length directions. The denier of the single fiber may be 0.1-5.6 dtex per filament. The thickness of the yarn is about 33-110 dtex.

Polytrimethylene terephthalate fibers are used in the form of knitting yarns of bidirectional warp-knitted fabrics, which can be ring-spun yarns, air-spun yarns, etc. ~-Strong twisted yarn, mixed fiber yarn, false twisted yarn (including POY drawn false twisted yarn), fluid jet processed yarn, etc. Furthermore, the bidirectional warp knitted fabric of the present invention is blended with other fibers such as natural fibers represented by wool (short loose fibers or loose filaments (sirofil)) within a range of not impairing the purpose of the present invention, usually within a range of 30% by mass. etc.), can be mixed with mixed fibers (high shrinkage yarn and different shrinkage yarn blending, etc.), cross-twisting, composite false twisting (elongation difference false twisting, etc.), double-fed gas jet processing yarn, etc.

In the present invention, the elastic fibers interwoven with polytrimethylene terephthalate fibers can be polyurethane-based fibers with elastic shrinkage performance of more than 100% elongation at break and fineness of 11 to 78 decitex, preferably 17 to 44 decitex. , Polyetherester-based arbitrary elastic fibers. As long as it is an ordinary polyurethane-based elastic fiber, its polymer and spinning method are not particularly limited.

In the dyeing and heat-setting process of elastic fibers, it is best to use the conditions that the fibers whose stretchability is not damaged are usually treated at a temperature around 190°C. The form of the elastic fiber may be pair yarn (beas yarn), core-spun yarn, or twisted yarn, and is not particularly limited.

The two-way warp knitted fabric of the present invention is a warp knitting machine with a needle bed that reeds polytrimethylene terephthalate fibers on the front side and elastic fibers on the back side, and uses closed loops and/or open loops to form loops. Knitted fabric woven from 2 pieces of bar weave. Therefore the two-way warp knitted fabric of the present invention is the organization that can be woven with 2 guide yarn bars. Representative organizations are: double-bar warp flat weave, double-bar warp velvet weave, half-furrow weave (stone wool), back half-furrow weave, warp velvet weft, weft satin weave (サテン), double-bar warp warp satin weave. The stretch function and crimp of bidirectional warp knitted fabric vary greatly with different tissues. For example: the back lap yarn of the front weave is a thin fabric with a gauge below 1, which is easy to curl. If the gauge is more than 3, it is a thick fabric, the style becomes hard, and the stretchability is low. There is no elasticity in the weft direction when the needle backing yarn of the back weave is 0 gauge, and when the gauge is more than 2, adjacent elastic yarns will fuse with heat at the contact part and intersection point in the fabric and become hard during dyeing and finishing. . Therefore, the selection of the combination of lapped yarns on the back of the needle is preferably weft satin, half furrow, more preferably half furrow weave, but there is no limitation.

The following shows are not intended to be limiting, but are examples of preferred weaving structures. (1) Front bar 2 stitches, commonly known as half furrow knitted fabrics

10/23 on the front, 12/10 on the back (2) The half furrow weave with the front weave and the back weave staggered

Front side 10/23 Back side 10/12 (3) half furrow combined with open coil and closed coil

Front 10/23 Back 21/01

The ratio of the number of rows and the number of columns per unit area of the final knitted fabric of the present invention is adjusted to the density ratio of the knitted fabric represented by formula (1) to be 1.55 to 2.35, which can form the unique soft style of the polytrimethylene terephthalate fiber on the front, And can suppress the curl of the two-way warp knitted fabric.

The knitted fabric density ratio in the present invention is the density ratio of the knitted fabric after dyeing and finishing, and the fabric shrinkage after the fabric is looped must be taken into account when designing the knitted fabric. This density ratio is represented by the number of turns per 2.54 cm, and is obtained by dividing the number of columns/2.54 cm of the warp density by the number of rows/2.54 cm of the weft density.

When the knitted fabric density ratio is less than 1.55, curls are likely to occur at the left and right ends of the bidirectional warp knitted fabric in the transverse direction, and when the knitted fabric density ratio exceeds 2.35, curls are likely to be formed at the upper and lower ends of the bidirectional warp knitted fabric. The preferred knitted fabric density ratio is 1.65-2.25.

When using the density ratio of the present invention to design the knitted fabric, basically changing the needle size of the knitting machine can also achieve the purpose of the present invention. For example: in the case of 28 needles, the most preferred knitted fabric density ratio is: 1.56-1.93; in the case of a 36-needle knitting machine, the most preferred knitted fabric density ratio is: 1.85-2.35, the finer the density ratio of knitted fabrics The most preferable range tends to be larger.

The design method when the density ratio of two-way elastic knitted fabric is in the range of 1.55 to 2.35 is to design the knitted fabric: for example: the length of the feeding yarn (lanna-) of the elastic yarn when knitting into a loop (also called let-off, which means forming one The length index of the wire of the coil, the larger the number of the fabric of the same organization, the larger the coil formed, which is expressed by the length of 480 columns in the field of warp knitting) It needs to be compared with nylon fiber, polyethylene terephthalate fiber and The amount of elastic fiber interwoven knitted fabric is large. In addition, the number of rows at knitting timing (indicating the height of one stitch at the time of knitting, the larger the number of crimps in the knitted fabric, the higher the density.) needs to be larger. After weaving, the two-way warp knitted fabric adopts relaxation and scouring at 90°C for 1 minute. When pre-setting the tenter after scouring, the tension setting is used to control the shrinkage within the range of the density ratio of the present invention, so that the width and length after dyeing are approximately It is the same density or the same density ratio as heat setting is used for final setting to obtain the density ratio determined by design, which must be used to design the length of yarn feeding and the number of rows on the machine for polypropylene terephthalate fiber and elastic fiber .

The setting conditions can be selected within the range of conditions of 150 to 200° C. and 30 to 60 seconds. It is best to carry out at about 190°C when pre-setting, and at about 170°C when finalizing. In this way, a warp-knitted fabric having good shapeability and no problem in color fastness can be obtained. For dyeing, any dyeing machine can be used, and it is preferable to use a liquid flow dyeing machine which is less prone to dyeing defects.

For the bidirectional warp knitted fabric of the present invention, a tricot machine or a raschel machine can be used. The needle size of the warp knitting machine is not particularly limited. The warp knitting machine with 18-40 needles/2.54cm can be arbitrarily selected according to the thickness of the fibers used.

As above, by adjusting the density of the warp knitted fabric, the curling phenomenon is overcome, and a soft style is obtained. Furthermore, bidirectional warp knitted fabrics without washing shrinkage and ironing shrinkage can be obtained.

The front side of the two-way warp knitted fabric with a knitted fabric density of 1.55-2.35 can be made of nylon fibers or polyethylene terephthalate fibers. However, when the density of knitted fabrics within the range of the present invention is used, the bidirectional warp knitted fabrics using nylon fibers have the problem of yellowing and are unsatisfactory knitted fabrics. On the other hand, the knitted fabrics using polyethylene terephthalate fibers Knits can only get fabrics that are stiff in style. For a soft style, it is loosely woven and has rolled edges.

The polytrimethylene terephthalate fiber used in the present invention may be composed of a copolymer of a third monomer other than the repeating unit of polytrimethylene terephthalate as described above. The third monomer may be terephthalic acid and its functional derivatives and 1,3-propanediol and its functional derivatives as other acid components and/or diol components. The polyester of the interpolymer may be an interpolymer in which one or two or more third monomers are added during the synthesis process. In addition, polyesters other than polytrimethylene terephthalate such as polyethylene terephthalate, nylon and polytrimethylene terephthalate may be synthesized separately, blended, and composite spun polymers (core-sheath type, "shoulder-to-shoulder" type, etc.). The third monomer added can be aliphatic dicarboxylic acid (oxalic acid, adipic acid, etc.), alicyclic dicarboxylic acid (cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acid (isophthalic acid, etc.), acid, sodium sulfoisophthalate, etc.), aliphatic diols (ethylene glycol, 1,2-propanediol, 1,4-butanediol, etc.), alicyclic diols (cyclohexanedimethanol, etc.), containing Aromatic aliphatic diols (1,4-bis(β-hydroxyethoxy)benzene, etc.), polyether diols (polyethylene glycol, polypropylene glycol, etc.), aliphatic hydroxycarboxylic acids (ω-hydroxyhexyl acids, etc.), aromatic hydroxycarboxylic acids (p-hydroxybenzoic acid, etc.). In addition, a polymer having one or more compounds (benzoic acid, glycerol, etc.) having one or more ester group-forming functional groups can also be used within a substantially linear range.

The spinning method of polytrimethylene terephthalate fiber can adopt the method of 2-3.5 times stretching and twisting after obtaining the unstretched filament at a winding speed of 1500m/min, or it can adopt direct spinning ~ stretching plus The direct stretching method (drawing spinning method) of twisting can also be used, and the high-speed spinning method (winding spinning method) with a winding speed of 5000 m/min or more can be used. Either method can be used. When spinning polytrimethylene terephthalate fibers, matting agents such as titanium dioxide, stabilizers such as phosphoric acid, ultraviolet absorbers such as hydroxybenzophenone derivatives, crystal nucleating agents such as talc, and lubricating agents such as aerosol may be contained. antioxidants, hindered phenol derivatives, flame retardants, antistatic agents, pigments, fluorescent whitening agents, infrared absorbers, defoamers, etc. for spinning.

The best form for carrying out the invention

The idea of the present invention is further clearly set forth below through examples. However, the invention is not limited to the described examples. In addition, the production method of the fiber used in the examples, the fineness measurement method of the elastic fiber, and the evaluation method of the performance of the bidirectional warp knitted fabric are as follows. (1) Manufacturing method of polypropylene terephthalate fiber used

The poly(trimethylene terephthalate) of ηsp/c=0.8 is obtained under the condition of spinning temperature of 265°C and spinning speed of 1200m/min to obtain undrawn filaments, followed by heating at 60°C of hot roll temperature, 140°C of hot plate temperature, drawing Stretching and twisting under the conditions of 3 times the elongation ratio and a drawing speed of 800m/min, two kinds of drawn yarns of 40dtex/34f and 56d/36f were obtained. The strength, elongation, initial breaking strength and elastic recovery rate at 10% elongation of 40d/34f drawn yarn are 2.7cN/dtex, 44%, 25cN/dtex and 97%, respectively. The strength, elongation, elastic modulus and elastic recovery rate at 10% elongation of 56d/36f drawn yarn are 2.8cN/dtex, 46%, 26cN/dtex and 98%, respectively. Among them, the method of measuring the elastic recovery rate of 10% elongation is: apply an initial load of 0.01cN/dtex on the sample, stretch it to 10% elongation at a certain rate of 20% elongation per minute, and then use the same The speed makes it shrink, and draw the stress-strain curve. When the stress in shrinkage is reduced to 0.01cN/dtex equal to the initial load, the residual elongation L can be calculated by the following formula.

Elastic recovery rate at 10% elongation = (10-L)/10×100(%)

In addition, the measurement method of the degree of polymerization viscosity ηsp/c is to dissolve the polymer in a 1g/dL o-chlorophenol solution at 90°C, and then transfer the resulting solution to the Ostwald viscosity tube (capillary), Measured at 35°C, calculated by the following formula. (Where: T: the time for the sample solution to fall [seconds], C: the concentration of the solution [g/dL])

ηsp/c=(T/T0-1)/C(2) Determination of elastic fiber fineness

Under the conditions of a temperature of 20°C and a relative humidity of 65% RH, the elastic fibers are left to relax and stand in a state of no tension, no load, and a straight line. Thereafter, 10 1-m-long samples were taken and weighed, and converted into a weight of 10,000 m, this value was the fineness of the fiber. (3) The bidirectional warp-knitted fabrics in Examples were evaluated by the following methods.

[1] Evaluation of curl phenomenon

Take two pieces of bidirectional warp-knitted fabrics with a warp direction of 100mm x weft direction of 100mm square samples, spread the needle-knitting arc surface and the sinking arc surface of the sample upwards and place it on a platform at a temperature of 20°C and a relative humidity of 65%. The edge curl of the test piece after 4 hours was evaluated according to the following criteria. Add a protractor to the rolled-up part to obtain the angle formed between the fabric end connection and the horizontal platform. When the angle is more than 90 degrees, there will be problems when sewing.

5 The angle of curl is less than 30 degrees

4 The angle of curl is less than 45 degrees

3 The angle of the curl is less than 90 degrees

2 The angle of curl is less than 130 degrees

1 The curling angle is more than 130 degrees

[2] Evaluation of style

The evaluation was performed based on the average value of the texture of a panel of 10 persons.

The fabric handle of the same weave using nylon was used as a criterion for evaluating the style. The fabric with excellent softness is scored 4-5 points comprehensively, the fabric with no change is set as 3 points, and the fabric with poor softness is set as 2-1 point.

I judge by the texture by the following criteria.

5 points The style is extremely soft and smooth

4 points Style is soft and smooth

3 points The style is equivalent to the nylon fabric of the same organization

2 points style is hard

1 point The style is hard, not suitable for underwear

[3] Evaluation of yellowing property

Samples were prepared in accordance with JIS-L-0855 weak test method for color fastness to nitrogen oxide gas. The judging method is to compare the yellowness YI value measured with a Macbeth color measuring machine (manufactured by Macbeth Co., Ltd.) with an untreated sample. A larger YI value indicates greater yellowing.

[4] Evaluation of heat setting properties

The heat setting testing machine of DAIT company is used. Cut the square fabric of 300mm in warp and weft as the sample, fix the sample on the yarn frame under the condition of no tension, (200mm in warp and 200mm in weft) press the central part of the sample into the heated mold, put it into the temperature Under the environment of 20°C and 60% relative humidity, evaluate the amount of deformation and the change of the style of the fabric after standing for 24 hours.

Types of heat setting testing machine Tensile setting machine made by Daito Co., Ltd.

The shape of the heating mold Metal cylinder

(Diameter 50em and height 30cm)

Temperature 180℃

Time 30 seconds

Pressing depth 20mm

Evaluation Standards

Good Deformation over 18mm with no change in style

Bad The amount of deformation is less than 18mm and the style has changed

[5] Evaluation of fuzziness

A KU-50 fluff tester manufactured by Kanai Important Metals Co., Ltd. was used. Evaluate the uniformity of the sinker arc and measure the thickness of the fabric under the conditions used for the raising of the loop. A fabric having a larger evaluation reference thickness indicates better fuzziness. (Example 1)

Polytrimethylene terephthalate of 40dtex/34f is used on the front side, and polyurethane elastic fiber of 22dtex (manufactured by Asahi Kasei Co., Ltd., trade name Roika) is used on the back side, and warped at a draft ratio of 80%. Elastic fiber, woven into half furrow tissue.

Knitting machine: 28 needles/2.54cm tricot knitting machine (カ-ルマィャ-Company)

Organization: Front 10/23, Back 12/10

Yarn feeding length: front 160mm back 90mm

Number of columns on the machine: 76 columns/2.54cm

The knitted fabric obtained under these knitting conditions was subjected to scouring at 90° C. for 1 minute and presetting at 190° C. for 45 seconds. The density setting during pre-setting is to set the density ratio of the number of columns/number of rows to be 1.83. After heat setting, it is dyed with a liquid flow dyeing machine. Afterwards, the same 110 columns/2.54cm, 60 rows/2.54cm as the pre-setting, that is, the final setting is carried out in a fixed-length and fixed-width manner. The final warp knitted fabric has a grammage of 170 g/m ² and a thickness of 0.61 mm. Various physical properties were evaluated, and the results are shown in Table 1. The obtained two-way warp knitted fabric is non-yellowing, soft in style, does not produce edge curling, and has excellent formability, and is the most suitable warp knitted fabric for underwear. (Embodiment 2-5)

Relative to embodiment 1, the front side feeding yarn is shortened to make a high-density fabric, and the density ratio of the set column/row is 1.93. In addition, the sample is made according to embodiment 1. Embodiment 3 is that relative to Embodiment 1, the yarn feeding on the front side is elongated to make a fabric with reduced density, and the density ratio of the set column/row is 1.55. In addition, a sample is made on the basis of Embodiment 1. Embodiment 4 is to make the high-density fabric by shortening the feeding yarn on the reverse side of the fabric relative to Embodiment 1. The density ratio of the number of columns/rows is set to be 1.81. In addition, a sample is made on the basis of Embodiment 1. Embodiment 5 is that relative to embodiment 1, the reverse side of the fabric is fed with longer yarns, and is woven into a low-density fabric. The density ratio of the number of columns/rows is set to be 1.70. In addition, a sample is made on the basis of embodiment 1. The crimpability, style, yellowing property and formability of the above final knitted fabrics were evaluated respectively, and the results are shown in Table 1.

The final two-way warp-knitted fabric is non-yellowing, soft in style, free from curling, and has excellent formability, and is the most suitable warp-knitted fabric for underwear. (comparative example 1)

Relative to Example 1, the yarn feeding length of the back reeding is shortened to make a high-density fabric. The density ratio of the number of columns/rows during the preset presetting is 2.37, and the density of the final fabric is changed. In addition, the final knitted sample is made on the basis of Example 1, and the occurrence of curling, style, yellowing, formability etc. The results are shown in Table 1. The obtained two-way warp-knitted fabric does not turn yellow, and the style is similar to the softness of nylon, but curling occurs, so it is not suitable for making underwear. (comparative example 2)

Relative to Example 1, the yarn feeding length of the front reeding is shortened to make a low-density fabric. The density ratio of columns/rows during heat setting was set at 1.5, which changed the density of the final fabric. In addition, samples were produced based on Example 1, and the curling property, style, yellowing property, and formability were evaluated. Table 1 shows the results.

The obtained two-way warp knitted fabric was non-yellowing and had a soft style, but was unsuitable for use in underwear due to curling. In addition, the moldability of the knitted fabric was also poor. (Example 6)

The polytrimethylene terephthalate fiber of 40dtex/34f is used as the front side, and the polyurethane type elastic fiber warped under the condition of 80% with a draft ratio of 22dtex on the back side (Asahi Kasei Industry Co., Ltd., trade name Roika) is woven into Half border tissue.

Knitting Machine 36 Needles/2.54cm Tricot Knitting Machine

Fabric Weave Front 10/23 Back 12/10

Yarn feeding length Front 126mm Back 76mm

Number of columns on the machine 80 columns/2.54cm

The fabric is subjected to relaxation and scouring at 90°C for 1 minute, and presetting at 190°C for 45 seconds. The density during pre-setting is set as: the density ratio of the number of columns/rows is 2.25, 180 columns/2.54cm×80 rows/2.54cm. After heat setting, it is dyed with a liquid flow dyeing machine. Then adopt the same conditions as pre-setting 157 columns/2.54cm×70 rows/2.54cm for final shaping. The obtained bidirectional warp knitted fabric had a grammage of 138 g/m ² and a thickness of 0.51 mm. Table 1 shows the evaluation results of various physical properties of the fabric. (Example 7-8)

Relative to embodiment 6 embodiment 7 shortens the length of front and back feeding yarn and makes tight fabric. Embodiment 8 lengthens the length of front and back feeding yarn and makes loose fabric. The density ratio setting of the number of columns/number of rows in presetting becomes 2.35 and 1.85. Changed the density of the final fabric. In addition, samples of the final fabric were prepared based on Example 6. The final samples were evaluated for curl appearance, style, yellowing property, and formability. The results are shown in Table 1. The obtained two-way warp knitted fabric is non-yellowing, soft in style, does not produce edge curling, has excellent formability, and is the most suitable warp knitted fabric for underwear and swimwear. (comparative example 3)

Relative to embodiment 6, reduce the length of yarn feeding, the density ratio of column number/row number when presetting, be set to 1.54, change the density of final fabric, make sample with embodiment 6 as a benchmark in addition. The final samples were evaluated for curl appearance, style, yellowing property, and formability. The results are shown in Table 1. The obtained two-way warp-knitted fabric was not yellow and had a soft style, but curling occurred, and it was a warp-knitted fabric not suitable for use. (comparative example 4)

Relatively embodiment 6 shortens the length of feeding yarn at the back side, makes the fabric of high density, improves the density ratio of column/row when presetting, is set to 2.38. The densities of the final fabrics were varied, and samples were prepared based on Example 6. The final samples were evaluated for curl appearance, style, yellowing property, and formability. The results are shown in Table 1. The obtained two-way warp-knitted fabric was not yellow and had a soft style, but curling occurred and the formability was poor, so it was a warp-knitted fabric not suitable for use. (Example 9)

The polytrimethylene terephthalate fiber of 56dtex/36f is used as the front side, and the polyurethane elastic fiber warped under the condition of 80% with a draft ratio of 44dtex on the back side (Asahi Kasei Industry Co., Ltd., trade name Roika) is woven into Half border tissue.

Knitting Machine 28 Needles/2.54cm Tricot Knitting Machine

Fabric Weave Front 10/23 Back 12/10

Yarn feeding length Front 165mm Back 80mm

Number of columns on the machine 81 columns/2.54cm

The fabric is subjected to relaxation and scouring at 90°C for 1 minute, and presetting at 190°C for 45 seconds. The density during pre-setting is set as: the density ratio of the number of columns/rows is 1.92, 115 columns/2.54cm×60 rows/2.54cm. After heat setting, it is dyed with a liquid flow dyeing machine. Then use the same column/2.54cm and the same row/2.54cm as pre-setting for final shaping. A bidirectional warp knitted fabric is obtained. The basis weight of the knitted fabric was 227 g/m ² , and the thickness was 0.66 mm. Table 1 shows the evaluation results of various physical properties.

The final two-way warp-knitted fabric is non-yellowing, soft in style, free from edge curling, excellent in formability and fluffing, and is the most suitable warp-knitted fabric for underwear and swimwear. (comparative example 5)

Make the front with the nylon fiber of 56dtex/36f, other conditions are woven into fabric identically with embodiment 9. Evaluations on the obtained fabrics are shown in Table 1. The style of the fabric is soft, but it is easy to turn yellow, and the phenomenon of curling appears, the formability is poor, and the uniformity of fluffing is poor, so it is a fabric that is difficult to use. (comparative example 6)

Make the front with the polyethylene terephthalate fiber of 56dtex/36f, and other conditions are identical with embodiment 9 to weave into fabric.

Evaluations on the obtained fabrics are shown in Table 1. The fabric is non-yellowing and curl-free, but has a stiff style. The formability of the fabric is good, but the fuzziness is poor, so it is not suitable for underwear and swimwear. (Example 10)

The polypropylene terephthalate fiber of 56dtex/36f is used as the front side, and the polyurethane elastic fiber (made by Asahi Kasei Industry Co., Ltd., trade name ロィカ) warped under the condition of 80% with a draft ratio of 44dtex on the back side is woven into Half border tissue.

Knitting machine 28 needles/2.54cm Tricot weave

Fabric Weave Front 10/23 Back 12/10

Yarn feeding length Front 206mm Back 80mm

Number of columns on the machine 81 columns/2.54cm

The fabric is subjected to relaxation and scouring at 90°C for 1 minute, and presetting at 190°C for 45 seconds. The density during presetting is set as: the density ratio of the number of columns/rows is 1.88, 113 columns/2.54cm×60 rows/2.54cm. After heat setting, it is dyed with a liquid flow dyeing machine. This is followed by final styling using the same columns/2.54cm, same rows/2.54cm as heatsetting. A bidirectional warp knitted fabric is obtained. The knitted fabric has a grammage of 250 g/m ² and a thickness of 0.70 mm. Various physical properties were evaluated, and the results are shown in Table 1.

The final two-way warp-knitted fabric is non-yellowing, soft in style, free from curling, and has excellent formability and fluffing properties. It is the most suitable warp-knitted fabric for underwear and swimwear. (Example 11)

The polypropylene terephthalate fiber of 56dtex/36f is used as the front side, and the polyurethane elastic fiber (made by Asahi Kasei Industry Co., Ltd., trade name ロィカ) warped under the condition of 80% with a draft ratio of 44dtex on the back side is woven into Half border tissue.

Knitting Machine 28 Needles/2.54cm Tricot Knitting Machine

Fabric Weave Front 10/45 Back 12/10

Yarn feeding length Front 250mm Back 80mm

Number of columns on the machine 81 columns/2.54cm

The fabric is subjected to relaxation and scouring at 90°C for 1 minute, and presetting at 190°C for 45 seconds. The density during presetting is set as: the density ratio of the number of columns/rows is 1.88, 110 columns/2.54cm×60 rows/2.54cm. After heat setting, it is dyed with a liquid flow dyeing machine. Then use the same column/2.54cm and the same row/2.54cm as pre-setting for final shaping. A bidirectional warp knitted fabric is obtained. The knitted fabric has a grammage of 280 g/m ² and a thickness of 0.72 mm. Various physical properties were evaluated, and the results are shown in Table 1.

The final two-way warp-knitted fabric is non-yellowing, soft in style, free of edge curling, good in shape and fluffing, and is the most suitable elastic warp-knitted fabric for underwear and swimwear. (comparative example 7)

Make the face with the nylon fiber of 56dtex/36f, other conditions are woven into fabric identically with embodiment 10. The resulting fabric was soft in style, but it was easy to turn yellow, curling was also observed, sufficient depth was not obtained, moldability was poor, and fuzziness was poor, making it a difficult-to-handle knitted fabric. (comparative example 8)

Use the polyethylene terephthalate fiber of 56dtex/36f as front, and other conditions are identical with embodiment 10 and weave into fabric. The fabric has good moldability, but poor fuzziness and hard style, so it is not suitable for knitted fabrics. (comparative example 9)

The polyethylene terephthalate fiber of 56dtex/36f is used as the front side, and the length of the front side coil and the back side coil is lengthened with relative comparative example 6 to make a loose weave fabric. Density during presetting is set as 94 rows/2.54cm and 60 rows/2.54cm, and others are woven into fabric identically with embodiment 9.

The evaluation of the final fabric is shown in Table 1. The fabric was not yellow, and its style was softer than that of Comparative Example 6, but lost the silky feeling unique to nylon. Poor formability and fluffing properties, and curls appear, so it is not suitable for warp knitted fabrics for underwear and swimsuits.

Table 1 Constituent fibers, weaving conditions, properties and performance evaluation of knitted fabrics Type of fiber used (F) Needle root/2.5cm Yarn feeding length Properties of knitted fabrics style curling The difference of yellowing YI value Formability Hairiness fiber Denier dtex amplitude (F)mm rigid fiber (B) mm elastic fiber Gram weight g/m ² Thickness mm C/2.5cm W/2.5cm C/W density ratio thickness Uniformity Example 1 PTT 40 2 pins 28 160 90 170 0.61 110 60 1.83 5 5 0.6 ○ - - 2 PTT 40 2 pins 28 155 90 158 0.57 116 60 1.93 5 5 0.6 ○ - - 3 PTT 40 2 pins 28 170 90 190 0.64 94 60 1.55 4 4 0.6 ○ - - 4 PTT 40 2 pins 28 160 80 181 0.62 109 60 1.81 5 5 0.6 ○ - - 5 PTT 40 2 pins 28 160 95 177 0.65 102 60 1.70 5 5 0.6 ○ - - 6 PTT 40 2 pins 36 126 76 138 0.51 180 80 2.25 5 5 0.6 ○ - - 7 PTT 40 2 pins 36 122 75 149 0.56 188 80 2.35 5 4 0.6 ○ - - 8 PTT 40 2 pins 36 135 80 135 0.51 148 80 1.85 5 5 0.6 ○ - - 9 PTT 56 2 pins 28 165 80 227 0.66 115 60 1.92 5 5 0.6 ○ 0.78 ○ 10 PTT 56 3 pins 28 190 80 250 0.70 113 60 1.88 4 5 0.6 ○ 0.83 ○ 11 PTT 56 4 pins 28 220 80 280 0.72 110 60 1.83 4 5 0.6 ○ - - comparative example 1 PTT 40 2 pins 28 160 70 191 0.67 142 60 2.37 3 1 0.6 ○ - - 2 PTT 40 2 pins 28 186 90 162 0.58 91 60 1.52 4 2 0.6 x - - 3 PTT 40 2 pins 36 141 98 132 0.50 123 80 1.54 3 1 0.6 ○ - - 4 PTT 40 2 pins 36 120 71 155 0.58 190 80 2.38 4 2 0.6 x - - 5 NY 40 2 pins 28 160 90 161 0.67 110 60 1.83 3 1 10.4 x 0.77 x 6 PET 40 2 pins 28 160 90 162 0.68 115 60 1.92 1 4 0.6 ○ 0.70 x 7 NY 56 3 pins 28 190 80 251 0.71 113 60 1.88 3 1 10.4 x 0.80 x 8 PET 56 3 pins 28 190 80 253 0.70 112 60 1.87 1 4 0.6 ○ 0.75 x 9 PET 56 2 pins 28 170 90 130 0.64 94 60 1.56 3 1 0.6 x 0.70 x

Possibility of industrial use

The two-way warp-knitted fabric of the present invention is non-yellowing, has a soft style, has a unique surface that cannot be obtained with nylon fibers, and is a warp-knitted fabric that can suppress curling, so it is excellent in usability such as sewing. It is a stretchable warp knitted fabric that is most suitable for underwear, swimsuits and other sportswear and outerwear.

Claims (3)

1. A two-way warp knitted fabric is characterized in that: the front side poly(trimethylene terephthalate) fiber and the back elastic fiber are interwoven to form a warp knitted fabric, and the knitted fabric density ratio represented by the following formula is 1.55～2.35. (Mode)

2. The bidirectional warp-knitted fabric as claimed in claim 1, the back side is that elastic yarns form stitch arcs. 3. The bidirectional warp-knitted fabric as claimed in claim 1, wherein the warp-knitted weave is a half furrow weave.