JPH09217242A - Production of elastic yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of efficiently and readily producing polyether ester-based elastic yarn having slight unevenness of physical properties. SOLUTION: A polyether ester-based polymer comprising polyethylene terephthalate and/or polybutylene terephthalate as a hard segment and a linear polyalkylene glycol as a soft segment is melt-spun and resultant undrawn elastic yarn is successively drawn. In the drawing, an initial draw ratio is set at >=1.1 times and the drawing is performed by controlling the draw ratio so that a drawing tension is kept at a constant value to obtain the objective elastic yarn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for efficiently producing a polyetherester-based elastic yarn having excellent elastic recovery performance and no physical property unevenness.

[0002]

2. Description of the Related Art Polyurethane-based or polyetherester-based elastic yarns are widely used for imparting stretch-back properties to woven and knitted fabrics used for clothing and industrial materials. Since these elastic yarns have elasticity, physical properties such as strength and elongation are likely to be uneven in the manufacturing process, and when the uneven elastic yarn is used as a woven fabric or knitted fabric, warps and wefts are generated and the quality is deteriorated. Will be inferior to.

In order to obtain a fabric of excellent quality, the obtained yarn is taken up from the cheese, the yarn is taken out, the strength and elongation and the elastic recovery rate are measured, and the yarn with large unevenness in physical properties is taken up. A method of selecting and eliminating cheese was adopted. However, it takes a lot of time to select such yarns, and there is a problem that productivity is poor.

[0004]

SUMMARY OF THE INVENTION It is a technical object of the present invention to solve the above-mentioned problems and to provide a method for efficiently and easily producing a polyetherester-based elastic yarn having few physical property irregularities. To do.

[0005]

The present inventors have arrived at the present invention as a result of extensive studies to solve the above problems. That is, the present invention relates to polyethylene terephthalate (PET) and / or polybutylene terephthalate (P
(BT) as a hard segment and a linear polyalkylene glycol as a soft segment, the polyester ester elastic yarn is melt-spun and subsequently stretched. The initial stretching ratio is set to 1.1 times or more, and the stretching tension is The gist of the present invention is to provide a method for producing an elastic yarn, which comprises drawing while adjusting a draw ratio so as to obtain a constant value.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. First, as the hard segment of the elastic yarn manufactured by the manufacturing method of the present invention, PET or PBT is used alone, or PET and PBT are mixed and used. PBT
The elastic recovery performance is excellent as the amount of PET increases, but the strength / elongation property is slightly inferior, while the strength / elongation property is excellent as the amount of PET increases, but the elastic recovery performance is slightly deteriorated. Are appropriately selected and used as a mixture, or these are used alone.

As the soft segment of the elastic yarn, linear polyalkylene glycol is used, and examples thereof include polyethylene glycol and polytetramethylene glycol (PTMG). Among them, the molecular weight is 500 to 3000.
PTMG is preferred.

The copolymerization ratio of the hard segment and the soft segment is not particularly limited, but is 80 by weight.
A copolymerization ratio of / 20 to 20/80 is preferable. When the amount of the soft segment is less than 20% by weight, the elastic recovery performance is likely to deteriorate, and when the amount of the soft segment exceeds 80% by weight, the strength / elongation property tends to be poor.

Additives such as antioxidants, pigments, light stabilizers, reinforcing agents and modifiers may be added as long as the characteristics of the elastic yarn are not impaired.

In the production method of the present invention, when the above polyetherester elastic yarn is drawn, the initial draw ratio is set to 1.1 times or more, and the drawing tension is measured by providing a tension measuring device in the drawing zone. The stretching is performed while adjusting the stretching ratio so that the stretching tension has a constant value.

If the initial draw ratio to be set is less than 1.1 times, the tension becomes too low to be detected and the draw ratio cannot be adjusted. The upper limit of the initial draw ratio is not particularly limited, but it is preferably set to about 2.0 times or less in order to prevent the wound yarn from collapsing due to tight winding. The set draw ratio needs to be changed depending on the spinning speed, but in the production method of the present invention, the spinning speed is set to 30%.
Melt spinning is preferably performed at a rate of 0 to 1000 m / min.

The stretching tension is preferably about 0.05 to 0.15 g / d, and the fluctuation range of the tension is 0.002 to 0.15 g / d.
It is preferable to adjust the amount to be about 01 g / d. And
When the tension variation is adjusted within this range when the 10 to 200 d yarn is drawn, the variation range of the draw ratio is 0.
It will be around 03 to 0.10.

Since the tension measuring device for measuring the stretching tension detects minute tension of this level, for example,
A strain gauge is attached to a plate made of carbon or glass fiber, and after a small amount of displacement of the plate is converted by the strain gauge into a potential difference, a signal of 4 to 20 mA or 1 to 5 V is passed through a dedicated amplifier circuit and converter. Those that convert are preferred.

When the fluctuation of the tension is converted into the above-mentioned signal, this signal is usually input to a data processing device or the like,
Correction and calculation are performed. Then, it is transmitted to the control device that adjusts the draw ratio so that the tension has a constant value.

When stretching is performed between the first godet roller (spinning side) and the second godet roller (drawing side), a tension measuring device is provided between these rollers when adjusting the stretch ratio, and the speed of the first godet roller is adjusted. By adjusting the stretching tension to a constant value by changing it,
It is preferable because the winding appearance when wound up in a package is more stable, the variation in fineness is reduced, and the physical properties of the obtained yarn can be further reduced.

According to the manufacturing method of the present invention, the strength
An elastic yarn having an elongation of about 0.7 to 1.5 g / d and an elongation of about 300 to 700% can be obtained.

Next, the present invention will be described with reference to the drawings. FIG. 1 is a schematic process drawing showing one embodiment of the manufacturing method of the present invention. The yarn 5 spun from the spinneret 2 installed in the melt spinning device 1 is cooled by the yarn cooling device 3, the oil agent is applied by the oil agent applying device 4, and then taken by the first godet roller 6. Then, the yarn 5 is stretched between the first godet roller 6 and the second godet roller 7, and in this stretching region, the tension measuring device 9 is provided to measure the stretching tension. The tension measured by the tension measuring device 9 is converted into a signal and transmitted to the control device 11 via the communication cable 10. The control device 11 inputs the received signal to a data processing device (not shown), corrects and calculates it, and then controls the speed of the first godet roller or the second godet roller so that the stretching tension becomes a constant value. The draw ratio is adjusted accordingly. The drawn yarn is wound by the winder 8.

[0018]

Next, the present invention will be specifically described with reference to examples. The various characteristic values in the examples were measured and evaluated by the following methods. (1) Intrinsic viscosity [η] Using an equal weight mixture of phenol and ethane tetrachloride as a solvent, measurement was performed at a temperature of 20 ° C. (2) Elastic recovery rate (100%, 200%) Using Tensilon UTM-4-100 made by Orientic Co., Ltd., a yarn with a sample length of 10 cm and a tensile speed of 10 cm / min was 100%.
Then, the elastic recovery rate was calculated according to the following equation. The number of measurements is 20
The average value and standard deviation were calculated. Elastic recovery rate (%) = [(E ₀ −E ₁ ) / E ₀ ] × 100 E ₀ : Original length when stretched to 100% and 200%
Length extended from (10 cm) E ₁ : Original length until stress appears when stretched again
Length longer than (10 cm) (3) Fineness After leaving the fiber in a relaxed (no load) state in an atmosphere of 20 ° C and 65% RH for 30 minutes, measure a 90 cm long yarn and measure its weight. Then, it was calculated by converting to a weight of 9,000 m. (4) Tensile strength Using Tensilon UTM-4-100 type manufactured by Oriente Co., Ltd., a yarn with a sample length of 10 cm was pulled to 100 m at a pulling speed of 10 cm / min.
It was measured every time. The number of measurements was 20 and the average value and standard deviation were calculated.

Examples 1 to 4 and Comparative Example 1 PTMG (molecular weight 2000) was used for the soft segment and PBT for the hard segment, the weight ratio of PBT and PTMG was about 50/50, the intrinsic viscosity [η] was 2.35, and the melting point ( Tm) is 185
The polymer at 0 ° C. is melt spun according to the process shown in FIG.
Wound up. At this time, the spinning temperature was 250 ° C and the diameter was 0.
After spinning from a spinneret having six 5 mm circular spinning holes and cooling, a silicone-based oil agent was applied and led to a first godet roller. Before starting winding, the speed V1 (spinning speed) of the first godet roller, the speed V2 of the second godet roller, and the initial draw ratio were set as values shown in Table 1. After the start of winding, the tension is measured by a tension measuring device having a strain gauge as shown in FIG. 1, the tension is converted into a signal, and the signal is transmitted to a data processing device and a control device. Stretching was performed while controlling the speed V1 of the first godet roller so as to obtain the values shown in Table 1.
The range of tension that actually fluctuated, the first that fluctuated with this
Table 2 shows the speed V1 and the draw ratio of the godet roller,
Table 3 shows the average values and standard deviations of the strength and elongation and the elastic recovery rate (100%, 200%) of the obtained elastic yarn (single yarn fineness 50 denier).
Shown in

Comparative Examples 2 to 3 No tension measuring device or control device was provided between the first godet roller and the second godet roller, and the winding was performed with the speeds V1 and V2 kept constant, and these speeds are shown in Table 1. Example 1 was repeated except that various changes were made. Table 2 shows the range of the actually changed tension, and the elastic elongation and elastic recovery rate (100%, 20%) of the obtained elastic yarn (single yarn fineness 50 denier)
Table 3 shows the average value and standard deviation of 0%).

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

As is clear from Table 2, Examples 1 to 4
Since the stretching was performed while adjusting so that the fluctuation of the tension was small, as shown in Table 3, the obtained elastic yarn had few variations in the strength and elongation and the elastic recovery rate, and had few physical property unevenness. It was On the other hand, in Comparative Example 1 in which the initial draw ratio was set to less than 1.1 times, the tension could not be measured accurately and the draw ratio could not be adjusted well.
For this reason, it was not possible to reduce variations in the strength and elongation of the obtained elastic yarn and the elastic recovery rate. Further, Comparative Examples 2 to 3 in which the tension measuring device and the control device were not provided in the stretching region.
Then, as shown in Table 2, the fluctuation of the tension during stretching is large,
As shown in Table 3, the obtained elastic yarn had large variations in the strength and elongation and the elastic recovery rate, and had large irregularities in the physical properties.

[0025]

EFFECTS OF THE INVENTION According to the present invention, it is possible to efficiently and easily produce a polyetherester-based elastic yarn having few physical property irregularities.

[Brief description of drawings]

FIG. 1 is a schematic process chart showing one embodiment of the production method of the present invention.

[Explanation of symbols]

 5 Thread 6 First Godet Roller 7 Second Godet Roller 8 Winder 9 Tension Measuring Device 10 Communication Cable 11 Control Device

Claims (2)

[Claims] 1. Polyethylene terephthalate and / or polybutylene terephthalate as a hard segment,
When melt-spinning a polyetherester-based elastic yarn having a linear polyalkylene glycol as a soft segment and subsequently drawing it, set the initial draw ratio to 1.1 times or more and make the draw tension constant. A method for producing an elastic yarn, which comprises drawing while adjusting a draw ratio. 2. Stretching is carried out between a first godet roller (spinning side) and a second godet roller (drawing side), a tension measuring device is provided between these rollers, and the speed of the first godet roller is changed to draw tension. The method for producing an elastic yarn according to claim 1, wherein the draw ratio is adjusted so that the value becomes a constant value.