JP5599686B2 - Polyester latent crimped yarn and method for producing the same - Google Patents

Description

  The present invention relates to a false twisted yarn of a side-by-side latent crimped yarn.

  With the recent stretch boom, many knitted and knitted fabrics made of side-by-side latent crimped yarn have been proposed. When the latent crimped yarn is used, not only the stretch property but also the stretch back property can be obtained, so that a woven or knitted fabric suitable for sports clothing, pants for women and the like can be obtained. However, the latent crimped yarn has a large crimp with a long pitch, and when used without twisting, there is a disadvantage that a large wrinkle is generated in the woven or knitted fabric and the quality of the woven or knitted fabric is impaired. Therefore, the texture of the woven or knitted fabric is suppressed by adding a twist in the medium to strong twist region to the latent crimped yarn.

  However, twisting in the medium to strong twist region generally tends to make the yarn rigid, which may be disadvantageous in terms of texture and gloss of the woven or knitted fabric. Therefore, studies have been made to impart further stretchability while suppressing the texture of the woven or knitted fabric by using twisting, which is a typical means for crimping the yarn.

  As an example, in Patent Document 1, a latent crimped yarn obtained by compound-spinning PBT (polybutylene terephthalate) and PET (polyethylene terephthalate) into a side-by-side type is stretched while intermittently applying an aqueous liquid. Means for false twisting is disclosed. Patent Document 2 describes a means in which a modified PBT and an unmodified PBT are composite-spun into a side-by-side type and then drawn to form a latent crimped yarn, which is then false twisted by a pin method.

JP-A-11-140739 JP 2009-138318 A

  However, the false twisted yarns described in Patent Documents 1 and 2 have a high hot water shrinkage rate, and twisting of latent crimped yarns is still necessary to suppress wrinkles generated in the woven or knitted fabric through dyeing. In particular, since the false twisted yarn described in Patent Document 2 is obtained by false twisting of a drawn yarn by a pin method, an improvement in stretchability of a woven or knitted fabric by crimping can be expected, but because of the pin method, It is necessary to suppress the twisting speed, and there is a disadvantage that the manufacturing cost increases accordingly.

  The present invention eliminates the drawbacks of the prior art as described above, and gives a soft texture and excellent stretchability to the woven or knitted fabric. It is a technical problem to provide a latent crimped yarn that is difficult to generate and a method for producing the processed yarn at low cost.

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have achieved a three-dimensionally dense without cost by performing high-speed false twisting of undrawn side-by-side latent crimped yarn under specific conditions. Knowing that processed yarns with crimps can be obtained, and using this processed yarn, it gives excellent texture and stretchability to the woven and knitted fabric, and the texture of the woven and knitted fabric even without twisting the processed yarn Has been found to be able to be suppressed, and the present invention has been made.

That is, this invention makes the following invention a summary.
(1) Polyester latent crimped yarn composed of a composite fiber in which two types of polyester polymers having different intrinsic viscosities are joined in a side-by-side manner, and the single yarn fineness is 2.5 dtex or less and the hot water shrinkage is 5% or less. A polyester latent crimped yarn characterized by having an elongation rate of 40% or more after a wet heat treatment at 100 ° C. for 30 minutes and an elongation change rate of 2 to 5 times.
(2) Only a crimped undrawn yarn made of a composite fiber having a single yarn fineness of 4.0 dtex or less and two kinds of polyester polymers having different intrinsic viscosities joined in a side-by-side type, with a processing speed of 500 m / min or more and a draw ratio 1.4 times or more, a heater temperature of 190 to 250 ° C., and false twisting in the twisting tension 0.4~0.6cN / dtex and a K value 0.6 to 0.9 following condition, to exchange fault processing after its A method of producing a polyester latent crimped yarn, which is characterized.

  According to the present invention, it is possible to provide a latent crimped yarn that gives a soft texture and excellent stretchability to a woven or knitted fabric, and that hardly causes wrinkles on the surface of the woven or knitted fabric even when used without being twisted. And according to the manufacturing method of this invention, it becomes possible to manufacture such a processed yarn at low cost under stable operation.

It is process schematic which shows an example of the manufacturing method of this invention.

  In the present invention, the single yarn fineness of the processed yarn needs to be 2.5 dtex or less from the viewpoint of giving the woven or knitted fabric an excellent texture with a soft feeling. Generally, when a yarn is false twisted, a crimp is imparted to the yarn, so that the knitted or knitted fabric tends to express a soft texture. On the other hand, when the single yarn fineness of the processed yarn is increased, the shape of the yarn is rigid. The woven or knitted fabric tends to develop a hard texture. When the single yarn fineness is 2.5 dtex or less, the former wins over the latter, and when the single yarn fineness exceeds 2.5 dtex, the latter wins over the former. Therefore, in the present invention, the single yarn fineness needs to be 2.5 dtex. The single yarn fineness is measured according to JIS L1013 8.3.1.

  The processed yarn of the present invention needs to have a hot water shrinkage of 5% or less. When the hot water shrinkage rate exceeds 5%, when the processed yarn is used without twisting, wrinkles occur in the woven or knitted fabric. In this case, if a middle to strong twist region is added to the processed yarn, the wrinkles can be suppressed, but the yarn becomes rigid and the texture of the woven or knitted fabric is lowered. The hot water shrinkage is measured according to JIS L1013 8.18.1 skelet shrinkage (Method A).

  The processed yarn of the present invention needs to have an elongation rate of 40% or more after wet heat treatment at 100 ° C. for 30 minutes. When the elongation ratio is less than 40%, the processed yarn is less likely to be crimped and the stretchability of the woven or knitted fabric is deteriorated. The elongation rate is measured according to JIS L1013 8.11B method.

  Furthermore, the processed yarn of the present invention needs to have an elongation change rate of 2 to 5 times. The elongation change rate is an index of the expression of crimp by wet heat treatment. As the elongation change rate increases, the processed yarn becomes higher crimp and the stretchability of the woven or knitted fabric is improved. The elongation change rate is specifically calculated by the following formula.

Elongation change rate (times) = (Elongation rate after wet heat treatment at 100 ° C. for 30 minutes) / (Elongation rate before wet heat treatment)
When the elongation change rate of the processed yarn is less than 2 times, the stretchability of the woven or knitted fabric is deteriorated. On the other hand, when it exceeds 5 times, the stretchability of the woven or knitted fabric is excessively increased, resulting in a decrease in dimensional stability.

  The processed yarn of the present invention can give an excellent function and texture to a woven or knitted fabric. To obtain such a processed yarn, first, two types of polyester polymers having different intrinsic viscosities were joined to a side-by-side type. A latent crimped undrawn yarn made of composite fiber is prepared.

  The single yarn fineness of the latent crimped undrawn yarn is preferably 4.0 dtex or less. This is to improve the texture of the woven or knitted fabric as described above, and the single yarn fineness becomes 2.5 dtex or less through a drawing step described later.

  The combination of the two polyester polymers may be a combination of the same or different polymers as long as the intrinsic viscosity is different from each other. The polyester polymer may be either a homopolymer or a copolymer. Furthermore, a third component may be included in the polymer as long as the effects of the present invention are not impaired. In the present invention, among these, a combination of PBT and PET is preferably employed.

  The intrinsic viscosity of each polymer is preferably 0.7 to 1.3 on the high viscosity side and 0.3 to 0.6 on the low viscosity side. The intrinsic viscosity is measured by extrapolation at a temperature of 20 ° C. using an Ubbelohde viscometer after heating and dissolving the polymer in an equal mass mixture of phenol and carbon tetrachloride and cooling.

  And it is preferable that it is 50 / 50-70 / 30 as mass ratio (high viscosity side / low viscosity side) of each polyester polymer in a composite fiber. By adopting such a mass ratio, it is possible to make the crimp of the latent crimped yarn obtained dense, which is advantageous in giving good stretchability to the woven or knitted fabric.

  In particular, when PBT and PET are employed as the two kinds of polyester polymers, it is more advantageous in terms of obtaining stretchability if the PBT side is bright (BR) and the PET side is semi-dal (SD) as the raster.

Latent crimp yarn of the present invention, after false twist under specific conditions such latent crimp undrawn yarn can be obtained by exchange fault processing.

  As false twisting conditions, first, the processing speed is preferably 500 m / min or more, and more preferably 600 to 800 m / m. When the processing speed is less than 500 m / min, production costs tend to increase, which is not preferable.

  The stretching ratio is preferably 1.4 times or more. When the draw ratio is less than 1.4 times, the elongation of the obtained processed yarn tends to be too large, and the strength tends to decrease.

  The heater temperature is preferably 190 to 250 ° C. When the heater temperature is less than 190 ° C., the crimp of the obtained processed yarn tends to be non-uniform, the hot water shrinkage rate increases, the stretchability of the resulting woven or knitted fabric decreases, and at the same time the processed yarn is When used without twisting, wrinkles are likely to occur on the surface of the woven or knitted fabric, which is not preferable. On the other hand, when the temperature exceeds 250 ° C., the yarn may be fused in the course of false twisting, and the texture of the resulting woven or knitted fabric is naturally deteriorated.

  The twisting tension is preferably 0.4 to 0.6 cN / dtex. When the twisting tension is less than 0.4 cN / dtex, yarn breakage is likely to occur during false twisting, and untwisted portions are likely to occur in the processed yarn, which is not preferable. On the other hand, if it exceeds 0.6 cN / dtex, yarn breakage is likely to occur during false twisting, and fluff is likely to occur in the processed yarn, which is not preferable.

  Furthermore, the K value is preferably 0.6 to 0.9. The K value refers to a calculated value of untwisting tension / twisting tension. In the present invention, when this value is less than 0.6, the twisting tension tends to be high and yarn breakage tends to occur. If it exceeds 9, the crimps of the processed yarn tend to be non-uniform and untwisted portions are likely to occur, so both are not preferred.

  As a device for false twisting the latent crimped undrawn yarn, a device called a high-speed false twister is used. As the false twisting method, a disk method, a belt nip method, etc. are generally applied, and the disk method is particularly preferable. In the case of the disk system, the material of the friction disk as the false twisting means is preferably polyurethane or ceramic, and the thickness of the disk is preferably 5 to 10 mm.

  As the heater in the false twisting device, a contact type, a high efficiency point contact type, or the like is suitable.

After false twist as above potential crimping undrawn yarn, which by exchange fault processing, yarn of the present invention is obtained. The exchange fault processing, it is possible to improve the processability of the unwinding properties and yarn of weaving knitting steps of package winding a yarn.

Fluid nozzle is used for the exchange fault processing, usually, the interlace nozzle is preferably used. The conditions for the exchange fault processing, the air pressure 0.1 to 0.6MPa, it is preferable respectively that the overfeed ratio and 1-4%.

Exchange-circuit the process, after the false-twisting, may be carried out continuously without winding the yarn, after the false-twist, may temporarily be carried out in terms of wound yarn.

  Next, a preferred method for producing the processed yarn of the present invention will be described with reference to the drawings.

FIG. 1 is a process schematic diagram showing an example of the production method of the present invention. This is after the false twist, corresponds to the method continuously to exchange fault process without winding the yarn.

The latent crimped undrawn yarn Y as the supply yarn is introduced into the supply roller 1 and false twisted between the roller 1 and the first take-up roller 4. The false twisting conditions are as described above. After the supply yarn is introduced, it is heat-set by the heater 2 and guided to the roller 4 through the false twisting means 3 (using a friction disk in the figure). Then exchange fault treated with fluid nozzle 5, via the second take-up roller 6, by Maki-up roller 7, wound on a package 8 as finished yarn.

  By the above method, the intended processed yarn is obtained. Even when the processed yarn of the present invention is used without twisting when obtaining a woven or knitted fabric, the surface of the obtained knitted or knitted fabric is suppressed. The processed yarn of the present invention is preferably used without twisting as described above, but it is a matter of course that twisting may be added according to the purpose of use. In addition, basically any woven or knitted fabric can be employed, and generally a dobby pattern, a jacquard pattern, etc. are employed in addition to flat, twill, and satin.

  For the weaving and knitting, a known means may be adopted. And after obtaining a living machine by weaving and knitting, this is normally dyed. By this dyeing process, it is possible to obtain a woven or knitted fabric that is excellent in stretchability and texture and has a reduced texture.

  Further, by using the processed yarn of the present invention, a woven or knitted fabric having a deep deep dyeing effect can be obtained. In the present invention, the L * value is used for verification of this dark dyeing effect. The L * value is an index for measuring the density of the woven or knitted fabric, and specifically, it is preferably 13 or less. It is recognized that the smaller the L * value, the better the deep dyeing effect.

  However, even if the processed yarn of the present invention is obtained, it is difficult to immediately recognize the dark dyeing effect. This is because the L * value is a numerical value of the deep dyeing effect that the woven or knitted fabric actually expresses, and the dyed woven or knitted fabric is the object of measurement. Therefore, it can be said that it is common to verify whether the processed yarn of the present invention has such a deep dyeing effect by actually producing a raw machine and dyeing it. The processed yarn of the present invention only has an ability to exhibit an excellent deep dyeing effect in the future.

  However, for the purpose of verifying the effect of deep dyeing, it is difficult to say that dyeing after weaving is too much work and practical. Therefore, in the present invention, the following method is adopted as a simple method for verifying the deep dyeing effect of the obtained processed yarn. That is, after a tubular knitted fabric was obtained using the processed yarn of the present invention, this was first treated in a scouring bath containing 2 g / L of “Sun Mall FL (trade name)” manufactured by Nikka Chemical Co., Ltd. as a scouring agent. Scour for 20 minutes at ℃. Next, a disperse dye “Dynics Black HG-FS 200% (trade name)” manufactured by Dystar is 10% omf, and “Nikka Sun Salt SN-130 (trade name)” manufactured by Nikka Chemical Co., Ltd. Dyeing is performed at a bath ratio of 1:50 at 135 ° C. for about 30 minutes in a dye bath containing 5 cc / L and acetic acid at 0.2 cc / L. Subsequently, it is subjected to reduction cleaning at 80 ° C. for about 20 minutes in a cleaning bath containing 5 g / L of a reducing cleaning agent “Bisnol P-55 (trade name)” manufactured by Yushi Kogyo.

  After the reduction cleaning, the L * value is measured by the following procedure. Specifically, a “CE-3100 spectrophotometer (trade name)” manufactured by Macbeth Co., Ltd. was prepared, the reflectance of the obtained tubular knitted fabric was measured, and then a density index was obtained from the color difference formula of CIE Lab. Is the L * value.

(Example 1, Comparative Examples 1-3)
PBT (BR) having an intrinsic viscosity of 1.05 was prepared as a high viscosity component, and PET (SD) having an intrinsic viscosity of 0.47 was prepared as a low viscosity component. Both components are fed to the compound spinning type melt extruder at a mass ratio (high viscosity side / low viscosity side) 60/40, and both components are merged at the back of the spinneret and joined to a side-by-side mold to spin the composite fiber. , Cooled and solidified. Then, the composite fibers were converged while applying an oil agent, and wound up as a latent crimped undrawn yarn of 80 dtex 24f via a take-up roller.

  Then, the latent crimped undrawn yarn obtained is supplied to the false twisting apparatus shown in FIG. 1, and the latent crimped undrawn yarns are falsely twisted under the conditions shown in Table 1, respectively. I got a thread.

  Next, the obtained four types of processed yarns were introduced into separate weaving processes without twisting, and four types of plain structures with warp density of 148 yarns / 2.54 cm and weft density of 118 yarns / 2.54 cm were used. I got a life machine. The obtained raw machine is scoured at 80 ° C. for 20 minutes, and then preset at 190 ° C. for 30 seconds. Thereafter, 10 disperse dyes (“Dynics Black HG-FS 200% (trade name)” manufactured by Dystar) are used. Using 4% omf, dyeing was performed at 135 ° C. for 30 minutes, and finishing setting was further performed at 180 ° C. for 30 seconds to obtain four kinds of fabrics.

(Comparative Example 4)
A processed yarn and a woven fabric were obtained in the same manner as in Example 1 except that the total fineness was changed to 80 dtex12f instead of 80 dtex24f.

  Table 1 shows the evaluation results of the processed yarn and the fabric obtained in Example 1 and Comparative Examples 1 to 4. In addition, L * value in a table | surface is L * value of the obtained textile fabric, and is measured according to the procedure of the above-mentioned L * value measurement.

The fabric obtained in Example 1 was excellent in soft texture and stretchability, and the texture of the fabric surface was suppressed. In addition, it has a deep dark dyeing effect.

  On the other hand, the stretch rate of the processed yarn of Comparative Example 1 did not reach the predetermined range, and satisfactory stretchability was not obtained in the woven or knitted fabric. Also, in the yarn quality of the processed yarn, because the draw ratio was too low during the false twisting conditions, the elongation of the obtained processed yarn was large and the strength was reduced, and the twisting tension was too low. The yarn breakage occurred several times along the way, and an untwisted portion was observed in the obtained processed yarn.

  In the processed yarn of Comparative Example 2, the elongation change rate did not reach the predetermined range, and a stretch fabric was not obtained. Moreover, since the heater temperature was too high during the false twisting conditions, the yarn was partially fused during false twisting, resulting in the loss of the fabric texture and stretchability at the same time.

  In Comparative Example 3, on the contrary, because the heater temperature was too low, the crimp of the resulting processed yarn became non-uniform, and the texture of the fabric was reduced. In addition, the hot water shrinkage rate of the processed yarn was increased. The stretchability was lowered and wrinkles were observed on the fabric surface.

  In Comparative Example 4, since the single yarn fineness of the processed yarn was too thick, the texture of the fabric lacked a soft feeling.

Y latent crimped undrawn yarn 1 supply roller 2 heater 3 false twist means 4 first take-up roller 5 fluid nozzle 6 second take-up roller 7 take-up roller 8 package

Claims (2)

A polyester latent crimped yarn composed of a composite fiber in which two types of polyester polymers having different intrinsic viscosities are joined in a side-by-side manner, having a single yarn fineness of 2.5 dtex or less and a hot water shrinkage of 5% or less, and A polyester latent crimped yarn characterized by having an elongation rate of 40% or more after a wet heat treatment at 100 ° C for 30 minutes and an elongation change rate of 2 to 5 times. Only a latent crimped undrawn yarn composed of a composite fiber having a single yarn fineness of 4.0 dtex or less and two polyester polymers having different intrinsic viscosities joined to a side-by-side type is processed at a processing speed of 500 m / min or more and a draw ratio of 1.4. more than doubled, heater temperature 190 to 250 ° C., and false twisting in the twisting tension 0.4~0.6cN / dtex and a K value 0.6 to 0.9 following condition, characterized by exchange fault processing after its A method for producing a polyester latent crimped yarn.