JP2000239949A - Production of highly stretchable double circular knitted fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a double circular knitted fabric with no stiff feel, pliable like a nylon fabric despite being a knitted fabric of polyester-based crimped fibers, and free from problems of yellowing and color fastness as well, and excellent in stretchability, in particular extension recovery. SOLUTION: This method for producing a double circular knitted fabric comprises using polytrimethylene terephthalate crimped yarns with a stretch elongation percentage of >=130% at >=60 wt.% based on the whole knitted fabric and knitting the yarns so as to be >=0.3 in cover factor CF defined as the formula given below (D is the fineness of the crimped yarn: denier; C is the number of courses/cm; W is the number of wales/cm).

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 highly elastic double circular knitted fabric having a soft feel and excellent stretch recovery.

[0002]

2. Description of the Related Art Conventionally, knitted fabrics made of crimped polyethylene terephthalate long fiber yarns are excellent in dyeing properties, especially light fastness and dyeing fastness, and are widely used for clothing applications. However, there is a problem that polyethylene terephthalate is used, such as inadequate rubber, and in some product fields such as sports applications, it has been desired to improve the texture and expand and contract properties, particularly the elongation recovery rate. Similarly, when a double circular knitted fabric is obtained using a crimped yarn of such a polyethylene terephthalate long fiber yarn, the texture is similarly hard, the elasticity is insufficient, and an excellent elongation recovery rate cannot be obtained. there were. In order to respond to this, when a double jersey made of crimped nylon long fiber yarn is used, stretchability and soft texture are excellent, but light resistance and dyeing fastness are poor and yellowing problem of white knitted fabric etc. Yes, it was not fully utilized.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above situation, and is a polyester-based winding which is soft, has no problem in dyeing fastness and the like, and has high elasticity and high elongation recovery. An object of the present invention is to provide a method for producing a double circular knitted fabric made of a compressed yarn.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and comprises a method of using a crimped yarn of a polytrimethylene terephthalate filament fiber having an expansion / contraction rate of 130% or more to 60% or more of a knitted fabric. Of a highly elastic double circular knitted fabric having a soft texture and excellent elongation recovery, characterized in that the knitted fabric is knitted so that the cover factor value (CF) shown in the following formula 1 is 0.3 or more. The gist is a manufacturing method.

[0005]

(Equation 1)

Here, D is the fineness (denier) of the crimped yarn, C is the number of courses per cm, and W is the number of wales per cm.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, at the time of producing a double circular knitted fabric, at least 60% or more of crimped polytrimethylene terephthalate long fiber yarn having an elongation of 130% or more is used. Polytrimethylene terephthalate is composed mainly of 1,3-propanediol and terephthalic acid, and is mainly composed of ethylene glycol, diethylene glycol, 1,4-butanediol, as long as its properties are not changed. A copolymer obtained by copolymerizing one or more components selected from isophthalic acid, 5-sulfoisophthalic acid, bisphenol A and the like may be used. Since this polytrimethylene terephthalate is softer than polyethylene terephthalate, and the crimped yarn used in the present invention has an elongation and contraction of 130% or more and is used for 60% or more of the knitted fabric, The obtained knitted fabric is
Good extensibility, usually stretched by hand, ie 1.5
The elongation rate under a kg load is 25% or more in both the course direction (warp) and the wale direction (weft), and the elongation recovery rate at that time is 97% or more.

When the expansion and contraction rate of the crimped yarn of the polytrimethylene terephthalate long fiber yarn used in the present invention is less than 130%, the elongation rate of the knitted fabric, particularly the elongation rate in the course direction (warp direction) is less than 25%. In other words, the elasticity recovery ratio in either or both of the warp direction and the weft direction is less than 97%, resulting in insufficient elasticity.

The expansion / contraction ratio in the present invention is determined as follows. First, five samples were made into a loop by hanging them on a glass rod, and a load of 1/10 g was applied to each denier of the indicated denier (fineness after false twisting). These five samples are put together. The bundle of 10 samples thus prepared is tightly tied with cotton thread at intervals of about 40 cm, and immediately deloaded. This sample is treated in hot water of about 90 ° C. for 20 minutes, air-dried for 24 to 48 hours, and then left in a standard state at a temperature of 20 ° C. ± 2 ° C. and a relative humidity of 65% ± 2 ° C. for 24 hours. Next, the upper part of the sample was fixed to a clamp, and 2/100 per denier of the indicated denier was used.
The sample is suspended with an initial load of 0 g, and after 30 seconds, a mark is made at a position 20 cm from the upper clamp to obtain a sample length a. Next, a load of 1/10 g per denier of the indicated denier is applied, and the length b of the sample after 30 seconds is measured. Thus, the expansion / contraction rate is obtained from the following equation. The number of times of measurement is set to 20 times, and the average value is shown. Stretch rate (%) = ((ba) / a) × 100

Next, the stretching and elongation rate used in the present invention is 130%.
A preferred method for obtaining the above crimped yarn will be described. That is, polytrimethylene terephthalate is used at 2600-35.
Spun at a spinning speed of 00 m / min, and the highly oriented drawn yarn (POY) wound up was set with the number of false twists T in the range of the following equation 2, a heater temperature of 140 to 180 ° C, and a draw ratio of 1.4 to 1.4. 1.6
It can be obtained by performing simultaneous stretch false twisting at twice. That is, in order to obtain a crimped yarn having a high expansion / contraction elongation, it can be achieved by using a highly oriented drawn yarn and realizing a high false twist number which is difficult to obtain with a drawn yarn.

[0011]

(Equation 2)

In the false twisting, the processing may be performed by only one heater or by two heaters.

In the present invention, the cover factor value (CF)
Is knitted under the condition that is 0.3 or more. As the knitting machine, a double-sided circular knitting machine having a normal cylinder and a dial may be used. The cover factor value is related to the density of the knitted fabric, and is theoretically the ratio of the area occupied by one loop of the yarn itself to the total area occupied by one loop of the knitting structure. It is obtained by the formula shown below. In addition, it is necessary to use a crimped yarn of polytetramethylene terephthalate having a stretching and elongation of 130% or more for 60% or more of the knitted fabric. When it is less than 60%, the elongation rate of the knitted fabric, particularly the elongation rate in the course direction (warp direction) is less than 25%, or the elongation recovery rate in either or both of the warp direction and weft direction is less than 97%. Insufficient properties,
The knit or elbow jumps out when worn and is not a good knitted fabric for elongation recovery. The finishing processing of the knitted fabric in the present invention may be performed in the same manner as a normal knitted fabric.

[0014]

The knitted fabric of the present invention can recover elongation only when the high crimped yarn of polytrimethylene terephthalate long fiber yarn exhibiting high elasticity and the resilience to the stress of the knitted fabric and the elongation recovery rate are appropriate when the knitting density is appropriate. It has been found that it contributes effectively.

[0015]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto. The evaluation of the knitted fabric in the examples was performed by the following method. (1) Expansion and contraction rate of the knitted fabric The knitted fabric is cut into a width of 5 cm and a length of 30 cm, and an initial load of 3 g is applied at a grip interval of 20 cm and an initial load of 100 g / min using a constant-speed elongation type tensile tester with a self-recording device. Draw a load elongation curve, and read the elongation rate at 1.5 kg stress from this curve. (2) Elongation recovery rate of knitted fabric Using a test piece obtained by cutting a knitted fabric to a width of 5 cm and a length of 3 cm, one end of the test piece is fixed, an initial load of 3 g is applied to the other end, and then 2
Mark at ₀ cm intervals (L ₀ ), gently apply a 1.5 kg load, leave for 3 minutes, measure the length between marks (L ₁ ), remove all loads, and leave for 3 minutes. Next, an initial load is applied, the length of the mark length (L ₂ ) is measured, and the elongation recovery rate is calculated by the following equation. Elongation recovery rate (%) = ((L ₁ −L ₂ ) / (L ₁ −L ₀ )) × 10
0

Example 1 A highly oriented drawn yarn 115d / 24f of polytrimethylene terephthalate multifilament was mixed with Mitsubishi Heavy Industries false twisting machine L.
Spindle rotation speed 40 × 10 ⁴ rpm, stretching ratio 1.552 times, false twist number 4000 t / m, heater temperature 1 with S-6 type
False twisting was performed at 70 ° C. The fineness of the obtained crimped yarn was 74d, and the expansion and contraction rate was 170%. Using an LPJW type circular knitting machine manufactured by Fukuhara Seiki Seisakusho Co., Ltd., the crimped yarn was used as a knitting structure diagram of Mock Milan Rib shown in FIG.
Supply to courses 2 and 4, 75d / 36 for F3 course
f) Polyethylene terephthalate long fiber crimped yarn (stretch rate 110%) is supplied, knitted at 16 courses / cm, 17 wales / cm, cover factor 0.35, and relaxed at 100 ° C. 160 ° C preset, 1
After performing high-pressure dyeing at 30 ° C. and final setting at 160 ° C., a stretchable circular knitted fabric according to the present invention was obtained in which the use ratio of crimped yarn of polytrimethylene terephthalate multifilament was 79%.

Example 2 In Example 1, the number of courses was 18 lines / cm and the number of wales was 1
The same procedure as in Example 1 was carried out except that knitting was performed at 9 yarns / cm and a cover factor value of 0.39, and the use ratio of the crimped yarn of polytrimethylene terephthalate multifilament was 80%.
Of the present invention was obtained.

Comparative Example 1 In Example 1, the number of courses was 13 lines / cm and the number of wales was 1
Except for knitting at 4 yarns / cm and a cover factor of 0.28, the same procedure as in Example 1 was carried out except that the use ratio of the crimped yarn of polytrimethylene terephthalate multifilament was 77%.
The circular knitted fabric of Comparative Example was obtained. Table 1 shows the evaluation results of the knitted fabrics of Examples 1 and 2 and Comparative Example 1.

[0019]

[Table 1]

As is clear from Table 1, the knitted fabrics of Examples 1 and 2 are soft knitted fabrics and excellent in elongation rate and elongation recovery rate, and are preferable knitted fabrics. The knitted fabric had no thick feeling and the elongation recovery rate was 94%, which was poor recovery.

[0021]

According to the present invention, it is as soft as nylon and has an excellent elongation rate of the knitted fabric, has a good elongation recovery rate, and has no problems of yellowing and dyeing fastness which are disadvantages of nylon. Thus, it is possible to easily obtain an optimal knitted fabric for a garment in which the elongation rate and the elongation recovery rate of a sports garment are particularly problematic.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of a knitted fabric according to the present invention in a yarn feeding order.

Claims (1)

[Claims] 1. A crimped polytrimethylene terephthalate filament yarn having an elongation of 130% or more is used for 60% or more of a knitted fabric, and a cover factor value (CF) expressed by the following formula 1 is 0.1%. A method for producing a highly elastic double circular knitted fabric, characterized in that the knitted fabric is knitted so as to have three or more. (Equation 1) Here, D is the fineness (denier) of the crimped yarn, and C is 1 cm.
The number of courses per unit, W, is the number of wales per cm.