JPH0424255A - Stretchable warp knit fabric - Google Patents

Abstract

PURPOSE:To obtain the title warp knit fabric having excellent elasticity, flat surface and washing stability, by knitting a polyamide multifilament having a specific initial Young's modulus into warp knitted fabric and heat-treating under a specific condition. CONSTITUTION:A polyamide multifilament having 200-300kg/mm<2> initial Young's modulus is knitted into warp knit fabric and the warp knit fabric is set in dry heat in an at least 10% elongated state in the knitting direction. The prepared warp knit fabric is set in wet heat while maintaining in a nonshrinkable state and relaxed in wet heat to give the objective warp knit fabric having characteristics of >=60% elongation in lateral direction, >=70% instant elastic recovery ratio in the lateral direction and <=5.0% shrinkage percentage of washing (lateral and longitudinal directions).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stretchable warp knitted fabric having high elasticity. More specifically, due to its high elasticity, which is not found in conventional warp knitted fabrics, it can be usefully used in the field of clothing such as sportswear and lingerie, as well as in the field of materials for molding, such as inner materials for shoes and base fabrics for synthetic leather. Regarding warp knitted fabrics.

[Conventional technology]

In order to impart high elasticity to conventional warp-knitted fabrics, polyurethane elastic yarns are inter-knitted, or high-crimp yarns formed by false twisting or crimped yarns formed by conjugates are knitted or inter-knitted. It is known.

[Problem to be solved by the invention]

The conventional high-stretch warp knitted fabrics described above have various problems.

That is, since polyurethane elastic yarn is expensive, the uses of warp knitted fabrics using it are limited due to price.

In addition, crimpable yarns produced by false twisting or conjugation have the problem that grains are generated on the surface of the knitted fabric due to the crimping of the constituent yarns, deteriorating the quality, and only thick warp knitted fabrics can be obtained.

The present invention solves the problems of conventionally known elastic warp knitted fabrics, has excellent elasticity (stretchability) and a smooth surface, and can obtain thin warp knitted fabrics if necessary. It is an object of the present invention to provide a warp knitted fabric that can be manufactured at low cost and a method for manufacturing the warp knitted fabric.

[Means to solve the problem]

The object of the invention consists of a polyamide multifilament having an initial Young's modulus of 170-255 kg/mm'',
This is achieved by a stretchable warp knitted fabric having the following properties.

Elongation in the horizontal direction: 60% or more Instantaneous elastic recovery rate in the horizontal direction: 70% or more Washing shrinkage rate (vertical and horizontal directions) 5.0% or less The preferred manufacturing method for the stretchable warp knitted fabric of the present invention is 200 to 3
A warp knitted fabric obtained by knitting a warp knitted fabric using polyamide multifilament having an initial Young's modulus of 00 kg/mm2, dry heat setting the warp knitted fabric in a state where the warp knitted fabric is stretched by at least 10% in the knitting direction. It is characterized in that it is heated and set in a state where it does not substantially contract, and then subjected to a heat relaxation treatment.

The thermal relaxation treatment includes a dyeing process.

In other words, the obtained stretch warp knitted fabric can be used in the material field,
If coloring is not required, a thermal relaxation treatment may be sufficient; on the other hand, if coloring is required in the clothing field, the thermal relaxation treatment may be performed in parallel with the dyeing process.

The stretchable warp knitted fabric of the present invention has a weight of 200 to 300 kg/+
It is necessary to knit using 100% polyamide multifilament having an initial Young's modulus of +na2, and if a multifilament with an initial Young's modulus exceeding 300 kg/mm2 is used, dry heat setting during finishing of the warp knitted fabric, Heat setting significantly hardens the texture, which is particularly undesirable when used in the clothing field. Furthermore, if a multifilament having an initial Young's modulus of less than 200 kg/mm 2 is used, the multifilament will be elongated by the tension during diameter adjustment or knitting when knitting a warp knitted fabric, and warp lines will occur, which is undesirable.

As the polyamide multifilament used in the present invention, various polyamide multifilaments such as nylon 6 and nylon 66 can be used.

The manufacturing method for obtaining the polyamide multifilament having an initial Young's modulus of 200 to 300 kg/positive 2 includes, for example, a method of spinning at a high speed of 4,000 to 7,000 m/min and winding it as it is; Various manufacturing methods such as a winding method can be used so that the above-mentioned initial Young's modulus value can be obtained at a stretching ratio of 1.4 times or less, preferably 1.3 times or less. However, in consideration of manufacturing costs, it is preferable to adopt a method of spinning at high speed and winding the fiber into five coils.

The structure and gauge of the warp 4i fabric of the present invention are not particularly limited, and a knitting machine gauge that is commonly used may be set to match the thickness of multifilament. For example, by creating a half tricot structure using a 30 d/10 f multifilament warp knitting machine with 36 gauges and two reeds, it becomes smooth and thin, making it suitable for clothing.

When finishing the warp knitted fabric of the present invention, it is necessary to perform dry heat and warm heat setting while pulling it in the vertical direction, that is, in the knitting direction. Conventionally, nylon fibers have a small setting effect before dyeing, and if high temperature treatment is performed to obtain a stronger setting effect, the silk becomes hard, so it has been necessary to minimize the tension and processing temperature of the silk fabric. By using multifilaments with a low Young's modulus, the warp-knitted fabric of the present invention can suppress the curing of the silk fabric after setting, which allows it to be stretched in the vertical direction, which was impossible until now, using dry heat and warm heat. The set is now available. The range in which the warp knitted fabric is stretched during setting in the present invention is preferably 10% or more, preferably 20% or more in terms of the density of the gray fabric, and can be set as appropriate. In this case, the temperature and time conditions for the dry heat setting and warm heat setting may be the same as those for normal nylon fibers. When setting, it is necessary to combine a dry heat set and a warm heat set, and by doing so, the durability of elongation and recovery during thermal relaxation treatment, wearing, and washing can be improved. It can be made higher. Examples of devices that can be used in the dry heat setting and warm heat setting of the present invention include pin tenters, beam dyers, etc., but are not particularly limited to these devices.

The warp knitted fabric of the present invention is subjected to a thermal relaxation treatment after being subjected to the above-mentioned dry heat setting and thermal setting. This eliminates the moiré that occurs in the previous process, and also makes the hardened silk more flexible.

The apparatus used for the thermal relaxation treatment may be any apparatus capable of relaxing the warp knitted fabric in a thermal state, and a jet dyeing machine is suitably used when dyeing the warp knitted fabric.

The stretchable warp knitted fabric of the present invention obtained in this manner has a
% or more, an instantaneous elastic recovery rate in the horizontal direction of 70% or more, the initial Young's modulus of the polyamide multifilament that constitutes it is 170 to 255 kg/embryo 2, and the washing shrinkage rate (vertical, horizontal direction) is 5.0% or less, and has excellent elasticity.

In addition, since it is a warp knitted fabric made only of multifilaments, its surface is smooth. Furthermore, by appropriately selecting the multifilaments used, it is possible to create a warp knitted fabric that is thin, has excellent elasticity, and has a smooth surface. can be obtained.

Conventional warp knitted fabric (tricot) has an elongation of 4 in the horizontal direction.
If it exceeds 0%, the instantaneous elastic recovery rate will be less than 70%,
There is a problem that the knitted fabric form is greatly disturbed after being worn, resulting in poor appearance. In contrast, the stretchable warp knitted fabric of the present invention has an instantaneous elastic recovery rate of 70% or more even when the horizontal elongation is 60% or more, and as a result, it can be used as sportswear or lingerie. In case, the knee falls out,
There is no feeling of pressure or slippage when wearing. Furthermore, when used for molding, the high elongation makes it possible to reduce the stress during development, and as a result, the appearance of the resulting molded product can be improved.

Note that warp knitted fabrics generally have two different stretch properties in the warp direction, that is, in the knitting method due to their structure.

However, if the stretchability (elongation and instantaneous elastic recovery rate) in the horizontal direction is significantly improved like the stretch warp knitted fabric of the present invention, it will be suitable for use in the clothing and material fields. By doing so, it is possible to exhibit practically excellent stretchability.

The elongation and instantaneous elastic recovery rate in the present invention are based on JISL-1
It was measured by the following method in accordance with Method B (constant load method).

Measure the lengths Lo, L+, and L2 of three samples each having a width of 5 cm under the following loads.

Lo: Sample length (20cm) L after 1 minute under 20g load
, : After 5 minutes under a load of 200 g, L, : After 1 minute under a load of 20 g after removal of a 200 g load, the elongation and instantaneous elastic recovery rate were determined by the following formulas and are shown as average values.

The washing shrinkage rate in the present invention is a value obtained by JIS-L-1018 (G method) knitted fabric testing method (home washing machine method).

〔Example〕

The present invention will be explained in detail with reference to Examples below.

Example 1 Initial Young's modulus 205 obtained at a spinning speed of 4500 m/min
kg/mm2 nylon 66 multifilament 30
d/10 f was knitted into a half tricot cloth using a 36 gauge tricot machine manufactured by Karl Mayer. The knitted fabric density at this time was 76 coats/inch and 46 wool/inch.

Next, dry heat treatment is performed at 175℃ for 30 seconds with a 10% tension in the vertical direction using a heat setter, and then heat treatment is performed at 110℃ for 20 minutes using a beam dyeing machine while maintaining the density of the warp knitted fabric. I did it. The resulting silk fabric had a silk density of 54 coats/inch and 66 coats/inch. Next, we carry out the normal dyeing process of dyeing nylon using a jet dyeing machine, and use a water-absorbing softener as a finishing agent (
Processing was performed to attach 1% owf of Lulotex A 25 (manufactured by BASF). Finally, dry heat setting was performed at 170° C. for 30 seconds to obtain approximately the same density as the knitted fabric density after dyeing.

The obtained warp knitted fabric had a knitting density of 54 cos/inch and 65 wells/inch, and a basis weight of 90 g/m'.As shown in Table 1, this warp knitted fabric had a knitting density of 76.5%. It has horizontal elongation, instantaneous elastic recovery rate of 72%, and washing shrinkage rate of 3% in vertical direction.
．． 8% and 1.5% horizontally, and the initial Young's modulus of the polyamide multifilament is 174kg/mm.
2, it is a warp knitted fabric with excellent stretchability, softness, and little change in shape due to washing.

Example 2 Initial Young's modulus 2 obtained at a spinning speed of 7000 m/min
A warp knitted fabric was obtained by carrying out the same process as in Example 1 using 96 kg/mun2 of nylon 66 multifilament 30 d/10 f. As shown in Table 1, the warp knitted fabric (constituting polyamide The initial Young's modulus of the multifilament is 2
52 kg/mm”) was obtained, and this warp knitted fabric was obtained in Example 1.
Similarly, it has excellent stretchability and soft feel, and also has excellent shape stability after washing.

Comparative Example 1 Initial Young's modulus 1 obtained at a spinning speed of 3500 m/min
As a result of carrying out the same process as in Example 1 using 75 kg/m+m'' nylon 66 multifilament 30 d/10 f, as shown in Table 1, streak-like sink marks were observed on the surface of the knitted fabric at the stage of making silk fabric. This product had no commercial value.

Comparative Example 2 Initial Young's modulus 3 obtained at a spinning speed of 8000 m/min
50kg/fight” nylon 66 multifilament 30
A warp knitted fabric was obtained by carrying out the same process as in Example 1 using d/10 f. As shown in Table 1, this warp knitted fabric has excellent stretch properties in terms of instantaneous elastic modulus, but its elongation is insufficient, and furthermore, it is harder than Example 1 and undergoes a large change in shape when washed, so it is not suitable for the present invention. It was outside the scope of the product.

Comparative Example 3 The undrawn yarn obtained by spinning at a spinning speed of 900 m/min was
．． Nylon 66 multifilament 30 d / 10 f with an initial Young's modulus of 450 kg/2 after stretching at 0 times
A warp knitted fabric was obtained by performing the same steps as in Example 1 using the following. As shown in Table 1, the stretchability of this warp knitted fabric was almost satisfactory in instantaneous elastic modulus, but the elongation was insufficient and the texture was hard.

Comparative Example 4 Initial Young's modulus 24 obtained at a spinning speed of 5.000 m/min
0kg/mm' nylon 66 multifilament 3
Using 0 d / 10 f, a warp knitted fabric was obtained by carrying out the steps of Example 1 except for the heating setting using the beam dyeing machine. As shown in Table 1, the stretchability of this warp knitted fabric shows a nearly satisfactory instantaneous elastic modulus, but the elongation is insufficient, and the washing shrinkage rate is 8.4 in the vertical direction and 2 in the horizontal direction.
, 0%, and the washing durability was poor.

Comparative Example 5 Using the multifilament of Comparative Example 4, a warp knitted fabric was obtained by performing the steps of Example 1 except for dry heat setting using a heat setter. As shown in Table 1, the stretchability of this warp knitted fabric is excellent in instantaneous elasticity, but the elongation is insufficient, and the washing shrinkage rate is 5.0% in the vertical direction and 3.4% in the horizontal direction.
%, the washing durability was low and moire occurred.

As can be seen from the above results, the warp knitted fabric of the present invention shown in Example 1.2 not only has higher stretchability than the warp knitted fabric of the comparative example, but is also softer and has less morphological change due to washing. It was a knitted fabric. When lingerie was made using the warp knitted fabric of the above example, it followed the movements of the body well, and the feeling of hanging and coming off was much improved compared to Comparative Examples 2.3.

On the other hand, when the warp knitted fabric of the above example was used as an inner patch material for shoes, it showed a reduction in stress during molding and was able to reduce the occurrence of tearing during processing.

〔Effect of the invention〕

Since the stretchable warp knitted fabric of the present invention was constructed as described above, it had excellent stretchability and a smooth surface, and had excellent washing stability.

Furthermore, since the manufacturing method of the present invention can be carried out using conventional equipment, the stretchable warp knitted fabric of the present invention having excellent performance can be obtained easily and inexpensively.

Claims (1)

[Scope of Claims] 1. Stretchable warp knitted fabric made of polyamide multifilament having an initial Young's modulus of 170 to 255 kg/mm^2 and having the following properties: An elongation in the weft direction of 60% or more and instantaneous elastic recovery in the weft direction. Washing shrinkage rate (vertical direction, horizontal direction) 5.0% or less 2, 2
A warp knitted fabric is knitted using polyamide multifilament having an initial Young's modulus of 00 to 300 kg/mm^2,
The warp knitted fabric is dry-heat set in a state where it is stretched by at least 10% in the knitting direction, and the obtained warp-knitted fabric is maintained in a state in which it does not substantially shrink, and after the heat-setting, a heat relaxation treatment is performed. The method for producing a stretchable warp knitted fabric according to claim 1.