JPS6312182B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel method for producing highly stretchable textured yarn. Conventional highly elastic textured yarns made from synthetic filament yarns such as polyester synthetic filament yarns and polyamide synthetic filament yarns are first twisted and then subjected to false twisting, or after false twisting they are additionally twisted. It is manufactured with the help of real twisting. Such conventional methods for producing highly stretchable textured yarns have the disadvantage of increasing production costs because they involve two or more steps. On the other hand, various proposals have been made to obtain stretchable textured yarns in a single step consisting only of a false twisting step, but none have been able to meet the required high stretchability. The inventors of the present invention have conducted intensive research to solve these conventional drawbacks, and as a result, we have developed a method using synthetic fiber filament drawn yarn with a cutting elongation of 20 to 90% to improve the number of false twists, heater temperature, processing tension, etc. The present invention was achieved by discovering that if the conditions are set well beyond the conventional setting range, a highly elastic textured yarn that has never been obtained before can be obtained in a single process. That is, in the present invention, when false twisting synthetic fiber filament drawn yarn with a cutting elongation of 20 to 90%, the number of false twists Tw (T/m), heater temperature θ (℃), and twisting tension Te (g ) is set within the ranges shown in formulas (1) to (3) below, respectively, and false twisting is performed. 1.47×10 ² ρ≦θ≦1.80×10 ² ρ …(2) 0.12D≦Te≦0.24D …(3) Where, ρ: Density of filament drawn yarn (g/cm ³ ) Dr: False twisting D: Fineness (denier) of filament drawn yarn The present invention will be described in detail below. In the present invention, a drawn synthetic fiber filament yarn such as a polyester synthetic filament or a polyamide synthetic filament having a breaking elongation of 20 to 90% is used, and in order to add a high number of false twists to it, the twisting tension is applied to the yarn using a conventional false twisting method. It is important to set the tension higher than the tension level during processing. The twist angle during conventional false twisting processing is limited to 48 degrees, and if the twist angle is increased beyond that, the twisting tension will decrease, double twist will occur, the balloon will become larger, and the yarn will break. Breaks occur, making operation difficult. In the present invention, by increasing the false-twisting tension during the false-twisting process, the balloon during the process is made as small as possible to prevent yarn breakage due to the balloon, thereby obtaining a highly elastic textured yarn. Cutting elongation used for false twisting in the present invention: 20~
90% synthetic fiber filament drawn yarn has a spinning speed of 1000 ~
Cutting elongation of polyester or polyamide synthetic fiber filament spun at 4000 m/min.
%. The preferable range of elongation at break of such drawn yarn is 40 to 70%. In the present invention, the false twist number Tw (T/m) is calculated using the above formula (1).
The reason for setting the range of the expression is as follows. That is, Tw

If the value is lower than [Formula], the degree of twist of the yarn due to twisting becomes the same as the degree of twist of drawn yarn obtained by a commonly known method, and no high elasticity can be obtained. Tw again

When the value is higher than [Formula], the threadability is poor, and even if the thread is stiff, it easily breaks, resulting in poor workability, and it becomes impossible to obtain a thread that can withstand practical use. The reason why the heater temperature θ (° C.) is set within the range of the above equation (2) is as follows. That is, when θ is lower than 1.47×10 ² ρ, the crimpability of the yarn obtained is weak, and the stretchability after boiling is the same as that of false twisted yarn obtained by known methods. Furthermore, if θ is higher than 1.80×10 ² ρ, some parts of the yarn will be fused, impeding elasticity and becoming a weak yarn, making it impossible to obtain a yarn that can withstand practical use. moreover
If Te is lower than 0.12×D, double twist will occur at the twisted part during false twisting, the occurrence of balloons will increase, and yarn breakage will occur easily, making operation difficult. Also
If Te is higher than 0.24×D, single yarn breakage occurs when the false twisted yarn is finished, resulting in a fluffy yarn, and the strength of the yarn becomes weak, making it impossible to obtain a yarn that can withstand practical use. Therefore, the number of false twists Tw and the heater temperature θ
In order to obtain a highly stretchable textured yarn, it is necessary to set the twisting tension Te and the twisting tension Te within the ranges of the above formulas (1), (2), and (3). Since the present invention employs the above-mentioned configuration, highly stretchable textured yarn can be manufactured only by the false twisting process, and can be manufactured at low cost. Note that the false twisting process may be performed with only one heater or may be performed using a heater. Next, the present invention will be specifically explained with reference to Examples. Example 1 A drawn yarn of polyester filament with a cutting elongation of 52% obtained by spinning and stretching, 160.2 denier 48 filament was used with a false twisting machine ST-6 manufactured by Mitsubishi Heavy Industries.
The yarn was false-twisted in a mold under the conditions shown in Table 1 to obtain a highly elastic textured yarn. When a woven or knitted fabric was woven using this processed yarn, a highly elastic fabric could be obtained.

【table】

[Table] In Table 1, Test No. 1 is processed under conventional false twisting processing conditions and shows the expansion/contraction elongation rate of normally used processed yarn. Test No. 2 satisfied some of the conditions of the present invention, but the setting temperature was low, the crimp setability was poor, and the expansion/contraction rate was low.
Furthermore, although the processed yarns of Test Nos. 1 and 2 were knitted and woven, it was not possible to obtain a stretchable fabric. Test No. 3 satisfied the conditions of the present invention, and the fabric woven and woven from this processed yarn had more elasticity in warp and weft than conventional crimped yarn. In Table 1, the expansion/contraction/elongation rate represents the expansion/contraction/elongation rate after moist heat treatment. That is, in hot water at about 90°C,
Displayed denier (fineness after false twisting)
A load of 1/10 x 2 grams per denier is applied to a suitable rod to form a ring, and 5 samples are made. An initial load of 2/1000×10 g per 1 denier of the display denier is applied to each bundle of 10 samples thus made, and the length (L ₀ ) of the sample is measured after 30 seconds.
Next, apply a load of 1/10 x 10 grams per 1 denier of the indicated denier, and after 30 seconds, measure the length of the sample (L ₁ ) and find it from the following formula. The number of tests is 20 and the average value is expressed. Stretching and elongation ratio (%) = L ₁ - L ₀ /L ₀ × 100 Example 2 A polyamide filament drawn yarn with a cutting elongation of 62.8% obtained by spinning and drawing. Twisting machine ST-6
When false twisting was carried out in a mold under the following conditions, a highly elastic textured yarn with an elongation rate of 190.3% was obtained. When 100% of this processed yarn was used for knitting and weaving, it was possible to obtain a highly elastic knitted fabric with great elongation in both warp and weft. False twisting conditions Spindle rotation speed: 40× ¹⁰⁴ rpm False twist number: 4236ZT/m Heater temperature: 195℃ Stretching ratio: 1.319 Density ρ: 1.134g/m ² Twisting tension: 18g

Claims (1)

[Claims] 1. When false twisting synthetic fiber filament drawn yarn with a breaking elongation of 20 to 90%, the number of false twists Tw (T/
m) Production of highly elastic textured yarn characterized by false twisting by setting heater temperature θ (°C) and twisting tension Te (g) within the ranges shown in formulas (1) to (3) below. Method. 1.47×10 ² ρ≦θ≦1.80×10 ² ρ …(2) 0.12D≦Te≦0.24D …(3) Where, ρ: Density of filament drawn yarn (g/cm ³ ) Dr: False twisting Stretching ratio D: Fineness (denier) of filament drawn yarn