JPS6131210B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a torque yarn, and more particularly to a drawn and false twisted polyester textured yarn that has a two-layer structure based on the difference in yarn length and has torque. Conventionally, drawing and simultaneously false-twisting mixed fiber yarns having different physical properties that cause a difference in elongation rate during drawing and simultaneous false-twisting has been known in Japanese Patent Application Laid-Open Nos. 49-102915 and 1972-107204. However, in known stretch false twisting, the number of twists is 2100~2100 to prevent torque from occurring.

It is carried out in [Formula]. If the number of twists is within this range, the yarn will be separated into single fibers after false twisting and crimped, resulting in a non-torque yarn suitable for knitting. The present invention relates to a method for producing a polyester false-twisted yarn having a two-layer structure by actively applying torque to the false-twisted yarn. In the present invention, a raw yarn made of a mixture of single fibers made of polyester having different physical properties that cause a difference in elongation rate during stretching and simultaneous false twisting is used. A first-stage heater and a false-twisting device perform simultaneous stretching and false-twisting, and furthermore, a second-stage heater between the first delivery roller and a second delivery roller subsequent to the first delivery roller performs heat centrifugation. However, its characteristic point is that when the denier of the fiber after stretching and false-twisting is Dr, as the number of twists when false-twisting is performed at the same time as stretching, it corresponds to the denier,

[Formula] or

[Formula]. and Kuni

[Formula] or

[Formula] is optimal. In other words, when Dr is 150 denier, it is 1000-1600t/m, Dr
However, for 50 denier, 1700 to 2800t/m is optimal. FIG. 1 schematically shows the relationship between the number of twists and torque of the false twisted yarn according to the present invention. According to this, the torque increases as the number of twists increases, reaches a maximum, and then decreases as the yarn becomes bulkier. and,

[Formula] or more will result in a thread with less torque, and usually

False twisting is performed before and after (region A). The present invention is characterized in that, in the region (region B) where the torque is large in FIG. 1, raw fibers of mixed fiber yarns having different physical properties are pre-combusted to produce a two-layer structure yarn. Different physical properties when performing stretch false twisting can be achieved by changing the birefringence Δn, single fiber denier dr, cross-sectional shape, polymer chemical composition, viscosity, etc. It may be either. It may be spun simultaneously at the time of spinning. It does not matter if the raw yarn is spun at the same time during spinning or combined after spinning, for example, yarns combined at different spinning speeds. Due to the presence of fibers that are easily elongated and deformed during stretching and simultaneous false-twisting, a yarn length difference ΔL is produced in the fibers, resulting in a false-twisted yarn having a two-layer structure, mainly one forming an inner layer and one forming an outer layer. The temperature of the first stage heater in the process of simultaneous stretching and false twisting is 80°C to 210°C, preferably 120°C.
℃ to 180℃, and the aim is to suppress the occurrence of crimp and obtain a silk-like texture with excellent wrinkles and fullness after finishing as a fabric due to the effect of the two-layer structure. The method of the present invention is characterized in that the waxy touch characteristic of polyester knitted fabrics disappears. Furthermore, in the present invention, in order to temporarily stop the torque when carrying out the present invention, the false twisted yarn obtained above is heat set using a second stage heater. 2nd stage heater temperature
When T ₂ is set, if T ₂ is set to the following conditions with respect to T ₁ , handling as a processed yarn will be improved. That is, T ₁ −50<T ₂ ≦T ₁ and T ₂ is preferably the same temperature as T ₁ or lower than T ₁ by 50° C. In this way, the yarn twisting speed can be increased by additionally twisting the yarn after setting it with the second-stage heater. Additional twisting is performed in the opposite direction to the false twisting. If false twisting is performed in Z, additional twisting is performed in S, and if false twisting is performed in S, additional twisting is performed in Z to produce a highly twisted yarn with a low number of twists. This yarn is suitable for making jerseys and crepe de chine, and has the advantage of reducing costs compared to conventional yarns. Next, an example will be explained. Example 1 Two types of polyethylene terephthalate with intrinsic viscosities [η] = 0.68 and [η) = 0.77 were simultaneously spun at 1500 m/min and mixed in equal amounts to produce a 116 denier/48 filament yarn. This was false-twisted (50 denier/48 filaments) at a twist rate of 2100 t/m while being stretched 2.33 times at 195° C. to obtain a two-layered yarn having torque and suppressing the occurrence of crimp. Example 2 Polyethylene terephthalate with an intrinsic viscosity [η] = 0.68 was spun at a speed of 1500 m/min to obtain a 110 denier/48 filament yarn containing 24 filaments of triangular and pentagonal single fibers in cross section. Manufactured. 2.2 times the stretching and false twisting at 195℃ at 2000t/m
A processed yarn of 50 denier/48 filaments was obtained. Differences in yarn length appeared due to differences in cross-sectional shape, and a processed yarn with a two-layer structure and low crimpability was obtained. After going through the weaving, relaxing setting, and finishing steps and finishing with width adjustment, a habutae with a soft touch due to the two-layer structure effect with little crimp was obtained. Example 3 The same yarn as in Example 1 was drawn and false twisted using a drawing and false twisting machine equipped with two stages of heaters. That is, the first stage heater temperature was set to 195°C, the Z-twist was pre-combusted at a twist rate of 2100t/m while being stretched 2.33 times, and then
The second stage heater was set at 190°C with 6% overfeed. This false twisted yarn had a two-layer structure, low torque, and was easy to twist additionally. This false twisted yarn was twisted with an S twist of 1000 t/m to obtain a dioset, which had a sufficiently strong twisting effect and had a good texture.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the relationship between the number of twists and torque, in which the region indicated by A is the number of twists under normally practiced false twisting conditions, and the region indicated by B is the region for false twisting according to the present invention.

Claims (1)

[Claims] 1. Using a raw yarn made of a mixture of single fibers made of polyester having mutually different physical properties that cause a difference in elongation rate when false-twisting is carried out simultaneously with stretching, When performing simultaneous stretching and false-twisting using the first stage heater and false-twisting device, when the denier of the fiber after stretching and false-twisting is Dr, corresponding to the fiber denier,
A method for producing a polyester textured yarn having a two-layer structure, characterized by stretching and simultaneously false-twisting the number of twists in the range from [Formula] to [Formula]. 2. The method for producing a polyester textured yarn having a two-layer structure according to claim 1, wherein the first stage heater temperature _T1 is 80°C to 210°C. 3 Using a raw yarn made of a mixture of single fibers made of polyester having mutually different physical properties that cause a difference in elongation rate when false-twisting is carried out at the same time as drawing, a feed roller, a first delivery roller, and a first stage between the two rollers are used. When performing simultaneous stretching and false-twisting using a heater and a false-twisting device, when the denier of the fiber after stretching and false-twisting is Dr, it corresponds to the fiber denier,
The number of twists in the range from [Formula] to [Formula] is drawn and simultaneously false-twisted, and the second-stage heater is connected to the second delivery roller following the first delivery roller. 1. A method for producing a polyester textured yarn having a two-layer structure, characterized in that, when the temperature is T ₂ , T ₂ is set to T ₁ −50<T ₂ ≦T ₁ and heat setting is performed.