JP2001098433A - Method for producing knitted and deknitted yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a knitted and deknitted yarn capable of providing a fabric having a soft surface touch, proper stretchability and drapability and yet excellent surface quality. SOLUTION: This knitted and deknitted yarn capable of providing the fabric having a soft surface touch, proper stretchability and drapability and yet excellent surface quality is obtained by knitting a yarn composed of a polypropylene terephthalate, heat-setting the knitted fabric and then deknitting the knitted fabric.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a knit denit yarn obtained by knitting a yarn made of polypropylene terephthalate, heat setting it under no tension or tension, and then knitting it.

[0002]

2. Description of the Related Art Conventionally, crimped yarns for clothing include false twisting, rubbing, and indentation. Among these, false twisted crimps, which are mainly used, are strong crimps. Although it is an excellent property in terms of stretching, the surface of the fabric is rough and the quality is not good. In addition, the surface touch becomes "gagged", and it cannot be said that the fabric can be said to have a high quality feel.

[0003] On the other hand, the one obtained by abrasion or indentation method has good surface quality in terms of gently crimping, resulting in a high-quality fabric, but is extremely inferior in stretchability and drapability to the false twist crimping. Low productivity has become an issue and has not yet been produced.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a knit denit yarn which has a soft surface touch, moderate stretch and drape, and can be a good surface quality fabric. is there.

[0005]

The present invention has the following configuration to achieve the above object. That is, a knitted fabric is made of a substantially untwisted or twisted flat or crimped fiber yarn made of polypropylene terephthalate, and then heat-set with moist heat or dry heat under no tension or tension. This is a method for producing a knit deknit yarn, which is characterized in that the yarn is deknitted. In the tension set, not only the elongation of the loop of the knitted fabric but also the elongation action to the extent that the elongation of the material is accompanied is given.

[0006]

Embodiments of the present invention will be described below in more detail.

The polypropylene terephthalate of the present invention is a fiber made of polyester obtained by using terephthalic acid as a main acid component and 1,3 propanediol as a main glycol component. However, it may contain a copolymer component capable of forming another ester bond at a ratio of 20 mol%, more preferably 10 mol% or less.

The copolymerizable compounds include, for example, diphthalic acids such as isophthalic acid, cyclohexanedicarboxylic acid, adipic acid, dimeric acid and sebacic acid, oxyacids such as oxybenzoic acid, and 5-sodium sulfoisophthalic acid. Yes, on the other hand, as a glycol component,
For example, ethylene glycol, diethylene glycol,
Examples include, but are not limited to, butanediol, neopentyl glycol, cyclohexane dimethanol, polyethylene glycol, polypropylene glycol, and the like. Of course, two or more types can be copolymerized without being limited to one type.

Further, for example, titanium dioxide as a matting agent, fine particles of silica or alumina as a slipping agent, hindered phenol derivatives as antioxidants, and coloring pigments can be added as required. The form of the fiber may be a monofilament or a multifilament, but generally the latter is preferred.

[0010] Like the polyethylene terephthalate fiber, the polypropylene terephthalate fiber can be produced by drawing after melt spinning.

[0011] The reason why long fibers of polypropylene terephthalate fiber are used as a starting material in the present invention is that the fibers are soft fibers as a fiber matrix. This softness is represented by the initial tensile resistance (Young's modulus), and the Young's modulus of the polypropylene terephthalate fiber is 30 g / d or less, which is an extremely low level of about 1/3 that of polyethylene terephthalate.

The cross-sectional shape, surface morphology, presence or absence of crimp, crimped shape, thick and thin shape, fibrous strip, and high elongation characteristics of the polypropylene terephthalate fiber of the present invention are not restricted at all. Further, it goes without saying that not only fibers composed of 100% of polypropylene terephthalate but also fibers having at least a polypropylene-terephthalate polymer and having, for example, a side-by-side type laminated structure may be used. The strength is preferably 2.0 g / d or more, more preferably 3.0 g / d or more, from the viewpoint of the spinning property and the process passability. 2.0 strength
If it is lower than g / d, the rubbing action may cause fluff or breakage of the yarn, which is not preferable. The elongation may be 10% or more. More preferably, it is at least 20%.

[0013] If the elongation is 10% or less, single yarn breakage may occur during knitting or unwinding during weaving.
The latter cannot withstand the tension or impact force at the time of knockover, and the latter is not preferable in that it may even break the yarn during high-speed aging or weft flight during weaving. The hot water shrinkage is 5% or more, and the dry heat shrinkage at 150 ° C is also 5%.
I just need more.

The fineness of the single yarn of the polypropylene terephthalate fiber of the present invention is preferably from 0.1 to 10 denier, more preferably from 1.0 to 5.0 denier. If the single yarn fineness is less than 0.1 d, the fabric for clothing will not be tight, and if it exceeds 10 denier, on the contrary, the tightness will be too strong. The fiber cross-sectional shape of the present invention starts with a round cross section, triangular,
A rectangle, flat, hollow, or the like can be appropriately selected.

Further, the polypropylene terephthalate fiber of the present invention is substantially non-twisted or twisted. It is preferable to improve the process passability at the time of knitting and unraveling, but the means is not limited, and as an example, convergence by an interlace nozzle, or real twist, alternate twist, fusion, bonding with a sizing agent, etc. Any means can be used.

As a raw material for obtaining the knit denit yarn of the present invention, not only a polypropylene terephthalate yarn as described above but also a highly oriented undrawn yarn (P
OY) or undrawn yarn (UY). In the case of a highly oriented undrawn yarn or undrawn yarn, it is preferable to disassemble the knitted fabric which has been once formed, by heat setting while drawing (the drawing action spreads to the material itself) or after finishing drawing.

In the present invention, a knitted fabric is once created,
Next, the knitted fabric may be obtained by putting the knitted fabric into a steam setter and finally unwinding and winding with a winder, or winding the knitted fabric while setting heat with a dry heat heater or the like while knitting. Alternatively, a step of unwinding with a winder may be selected.

The heat setting of the knitted fabric of the present invention without tension is a mode in which the knitted fabric is set under a set atmosphere for a predetermined time without applying an external force. At this time, due to the shrinkage, a gentle loop-like crimp characteristic of the knit denit yarn is developed, and a smooth and beautiful surface feeling can be obtained.

The heat setting of the knitted fabric of the present invention under tension is defined as a system for extending the knit structure in the width and length directions within a range in which the material does not elongate. It includes two systems that extend the material by giving elongation equal to or greater than the knit structure. In the latter, if applied when UY or POY is used as a feedstock, it not only imparts a strong shaping effect, but also at the crossing point of the loop, due to stress concentration, flattened almost in the fiber diameter direction, and It has a fine uneven shape. The fine irregularities exhibit a dry feeling without sliminess peculiar to synthetic fibers in a delicate surface touch.

Also, depending on the stretching ratio and the heat setting temperature, soft texture and deep color can be expressed.

The heating method at the time of heat setting according to the present invention is performed by either wet heat using a steam setter or dry heat using a dry heat heater. This is because it is necessary to fix the cross-sectional deformation and the crimp by the shaping action by these heat sets.

[0022]

The present invention will be described in more detail with reference to the following examples. Example 1 7 consisting of polypropylene terephthalate
A tubular knitted fabric is formed from a drawn yarn of 5 denier 24 filaments using a 30-gauge tubular knitting machine, and is then steamed using a steam setter.
The set was performed at 0 ° C. for 20 minutes, and then the knitting was performed with a winder. The obtained yarn became a yarn excellent in stretchability and stretch recovery.

The yarn was interlocked with a 30 gauge circular knitting machine to obtain an interlock knitted fabric. Relaxing scouring (98 ° C), intermediate setting (160 ° C), dyeing (120
C), and the finishing set was dyed and finished. The obtained knitted fabric had good surface quality, had a soft and high-quality fine unevenness, and was excellent in stretchability and stretchback property. Comparative Example 1 A knit denit yarn was obtained under the same conditions as in Example 1 except that the drawn yarn made of polypropylene terephthalate was changed to a drawn yarn made of polyethylene terephthalate.

Using this yarn, a knitted fabric was prepared under the same conditions, and under the same dyeing finish conditions except that the dyeing temperature was 130 ° C., there was fine irregularities as compared with Example 1, but the quality was poor. Inferior in stretchability and stretchback property. Example 2 POY made of a polypropylene terephthalate polymer having a POY fineness of 112.5 denier and 24 filaments was supplied to a 24-gauge tube knitting machine to prepare a tube knitted fabric. Next, it was supplied to a turbo stapler of Turbo Corporation (USA). The knitted fabric at the time of supply was passed through a plurality of pretension bars, and the structurally stretched portion of the knitted fabric was elongated. Next, it was subjected to a pre-stretch zone, heat-set at a heater temperature of 250 ° F. (107 ° C.), and then unknitted with a winder to obtain a knit denit yarn (fineness: 90 denier).

The obtained yarn was provided with a zigzag two-dimensional crimp, and at the intersection of the loops, the fibers were shaped by stress concentration.

The yarn was interlocked with a 24 gauge circular knitting machine to obtain an interlock knitted fabric. This knitted fabric was dyed (120 ° C.) without relaxing scouring or intermediate setting, and then subjected to a dyeing finishing process for finishing setting. The obtained knitted fabric has a good surface quality, has a soft and dignified fine uneven surface feeling, and has excellent stretchability, stretchback property, and excellent deep color, and has sharpness, and A product with a natural appearance with a heather-like color effect was obtained. [Comparative Example 2] POY composed of a polypropylene terephthalate polymer was replaced with P composed of polyethylene terephthalate.
A knitted fabric was heat-set at the same stretch ratio and heater temperature as in Example 2 except that the knitted fabric was set to OY, and then unwound with a winder to obtain a knit denit yarn.

This yarn is fed to a 30 gauge circular knitting machine,
You have an interlock knitted fabric. This knitted fabric was dyed (130 ° C.) without performing relaxation scouring and intermediate setting, and then subjected to a finishing set to finish the product. The obtained knitted fabric had a rough surface and was of poor quality with no stitches. In addition, the texture was hard, and the shape of the unevenness was rough, and it was only "sagged". In addition, the color effect had a flow of heather and lacked a sense of quality. [Example 3] The polypropylene terephthalate knit denit yarn (90 denier) obtained in Example 2 was added with 300 t / d.
m twisted and plain woven fabric (finishing density x weft density = 10
4 / inch × 81 / inch) were obtained. The basic steps of dyeing and finishing were relaxing scouring, intermediate setting, alkali weight reduction processing (25%), dyeing and finishing setting, and resin (antistatic and the like) processing.

The obtained woven fabric had a soft surface touch and a feeling of moderate dryness, and had moderate stretch and drape properties. [Comparative Example 3] Using polyethylene terephthalate POY as a starting material, a knit denit yarn (90 denier) was obtained in the same process as in Actual Example 2.

A trial production of a woven fabric using the same twisting design, woven fabric design and dyeing finish design as in Example 3 resulted in a hard hand and poor drape.

[0030]

According to the present invention, there is provided a knit denit yarn having a soft surface touch, an appropriate stretch property and a drape property, and which can be a fabric having a good surface quality.

Claims (4)

[Claims] 1. A knitted denit which is characterized in that a knitted fabric is formed from a substantially untwisted or twisted flat or crimped fiber yarn made of polypropylene terephthalate, which is then heat set and then deknitted. Manufacturing method of yarn. 2. The method according to claim 1, wherein the heat setting is performed without tension. 3. The method for producing a knit denit yarn according to claim 1, wherein the heat setting is performed in a tensioned state. 4. The method for producing a knit denit yarn according to claim 1, wherein the tension-free or tension setting is performed by wet heat or dry heat.