JPH11302932A - Production of false twisted yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably produce a false twisted yarn excellent in quality and useful for a woven or knitted fabric or the like at a high speed by forming a relaxing step before the false twisting step of a polytrimethylene terephthalate multifilament. SOLUTION: This method for producing a false twisted yarn of a polytrimethylene terephthalate multifilament comprises a relaxing step before the false twisting step to provide the false twisted yarn. When carrying out a draw-false twist texturing of the polytrimethylene terephthalate multifilament, the false twisted yarn is preferably produced by carrying out the draw-false twist texturing comprising a drawing step, the relaxing step and the false twisting step in order.

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 polyester false twisted yarn, and more particularly, to a method for false twisting a polytrimethylene terephthalate multifilament.
The present invention relates to a method for stably producing high quality false twisted yarn at a high speed.

[0002]

2. Description of the Related Art Hitherto, as a polyester fiber excellent in elastic recovery and suitable for stretch materials, for example, Japanese Patent Application Laid-Open No. 9-78373 discloses a polyester false twisted yarn containing polytrimethylene terephthalate as a main polymer component. As a production method, a method of performing a false twisting process after drawing an undrawn yarn or a partially oriented undrawn yarn (POY), or a method of producing an undrawn yarn or a partially oriented undrawn yarn (P
OY) is described in a very common way of performing false twisting simultaneously with stretching. However, if the polytrimethylene terephthalate multifilament undrawn yarn or the polytrimethylene terephthalate multifilament partially oriented undrawn yarn (POY) is subjected to false twisting subsequent to stretching or false twisting at the same time as stretching, the processing tension is reduced. There are problems such as excessive fluffing due to too large size, and fluctuations in unwinding tension of the raw yarn pat, resulting in fluctuations in processing tension and frequent yarn breakage. False twisting could not be performed at the speed.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for false-twisting a high-quality false-twisted yarn which cannot be achieved by a conventional method, at a high speed when false-twisting a polytrimethylene terephthalate multifilament. It is to provide a way to do it.

[0004]

The present inventors have conducted intensive studies on the false twisting method of polytrimethylene terephthalate multifilament, and as a result, by performing false twisting processing by a specific method, a high quality false twist without fluff is obtained. The inventors have found a method for stably false twisting a twisted yarn at a high speed, and have completed the present invention. That is, the present invention provides a method for producing a false-twisted yarn, which comprises providing a relaxation step before the false-twisting step when false-twisting the polytrimethylene terephthalate multifilament, and drawing false-twisting the polytrimethylene terephthalate multifilament. This is a method for producing a false twist yarn, which comprises performing a stretch false twisting process in the order of a stretching step, a relaxation step, and a false twisting step.

Hereinafter, the present invention will be described in more detail. The polytrimethylene terephthalate multifilament in the present invention refers to a polyester fiber having a trimethylene terephthalate unit as a main repeating unit, and has a trimethylene terephthalate unit of 50 mol% or more, preferably 70 mol% or more, and more preferably 80 mol% or more. And more preferably 90% by mole or more of polyester fiber. Therefore, the total amount of the other acid component and / or glycol component as the third component is 50 mol% or less, preferably 30 mol%.
In the following, polytrimethylene terephthalate contained in a range of 20 mol% or less, more preferably 10 mol% or less is included.

[0006] Polytrimethylene terephthalate is produced by polycondensing terephthalic acid or a functional derivative thereof with trimethylene glycol or a functional derivative thereof in the presence of a catalyst under appropriate reaction conditions.
In this production process, one or more appropriate third components may be added to form a copolymerized polyester,
Polyester other than polytrimethylene terephthalate such as polyethylene terephthalate, nylon, and polytrimethylene terephthalate may be separately manufactured and then blended or composite-spun (sheath core, side-by-side, etc.).

The third components to be added include aliphatic dicarboxylic acids (oxalic acid, adipic acid, etc.), alicyclic dicarboxylic acids (cyclohexane dicarboxylic acid, etc.), and aromatic dicarboxylic acids (isophthalic acid, sodium sulfoisophthalic acid, etc.). ), Aliphatic glycols (ethylene glycol, 1,2
-Propylene glycol, tetramethylene glycol, etc.), alicyclic glycols (cyclohexanediol, etc.), aromatic dioxy compounds (hydroquinone bisphenol A, etc.), aliphatic glycols containing aromatics (1,4
-Bis (β-hydroxyethoxy) benzene, etc.), polyether glycols (polyethylene glycol, polypropylene glycol, etc.), aliphatic oxycarboxylic acids (ω
-Oxycaproic acid), aromatic oxycarboxylic acids (P
-Oxybenzoic acid, etc.). Also one or three
Compounds having more than one ester-forming functional group (such as benzoic acid or glycerin) can also be used as long as the polymer is substantially linear.

Further, matting agents such as titanium dioxide, stabilizers such as phosphoric acid, ultraviolet absorbers such as hydroxybenzophenone derivatives, crystallization nucleating agents such as talc, lubricating agents such as aerosil, and antioxidants such as hindered phenol derivatives. An oxidizing agent, a flame retardant, an antistatic agent, a pigment, a fluorescent whitening agent, an infrared absorbing agent, an antifoaming agent and the like may be contained. The present invention is to perform such false twisting of the polytrimethylene terephthalate multifilament, but as the polytrimethylene terephthalate multifilament yarn to be supplied to the false twisting,
After obtaining an undrawn yarn at a winding speed of about 1500 m / min,
It was obtained by a method of drawing by about 2 to 3.5 times, a direct drawing method in which a spinning-drawing step was directly connected, and a high-speed spinning method (spin draw or spin take-up method) with a winding speed of 5000 m / min or more. There is a yarn, and the polytrimethylene terephthalate multifilament yarn to be supplied to the draw false twisting process is preferably 2,000 m / min or more, preferably 2500 to 40 m / min.
There is a partially oriented undrawn yarn (POY) of polytrimethylene terephthalate multifilament spun at a winding speed of 00 m / min.

[0009] The polytrimethylene terephthalate multifilament yarn may be uniform or thick in the length direction, and may have a round, triangular, L-shaped or cross-sectional shape.
Polygonal types such as T-type, Y-type, W-type, Yatsuha-type, flat, dog-bone type, etc., multi-leaf type, hollow type and irregular type may be used. As a method of false twisting, any method such as a pin type, a friction type, a nip belt type, and an air twisting type which are generally used may be used, but in any method, a relaxation step is provided before the false twisting step. It is necessary.

[0010] The drawn yarn of polytrimethylene terephthalate multifilament is excellent in elastic recovery, but is very easily deformed by an external force. Therefore, the frictional resistance between filaments or the frictional resistance with a yarn path guide or the like is large, and the fluctuation is also large. It has the feature of being large. Therefore, when the drawn yarn is supplied to the false twisting step and false-twisted as it is, the unwinding tension of the raw yarn pat and the frictional resistance with the yarn path guide are larger than those of the conventional polyethylene terephthalate multifilament and the like. Since the fluctuation is large, the yarn feeding tension to the false twisting step and its fluctuation are large, and yarn breakage is likely to occur. By providing the relaxation step before the false twisting step, the yarn feeding tension to the false twisting step can be kept low and the fluctuation of the yarn feeding tension can be reduced, so that the false twisting tensions (T1, T2) and The fluctuation is reduced and yarn breakage can be improved.

When partially oriented undrawn yarn (POY) of polytrimethylene terephthalate multifilament is subjected to draw false twisting, a method of performing false twisting simultaneously with stretching in a false twisting step, which is generally performed, is as follows. In addition to the problem of the yarn feeding tension to the false twisting process and the magnitude of the fluctuation, the heat shrinkage stress of partially oriented undrawn yarn (POY) of polytrimethylene terephthalate multifilament is higher than that of polyethylene terephthalate multifilament or the like. As a result, the false twist tension becomes larger, and fluff and yarn breakage are likely to occur. Therefore, a method of drawing to a predetermined thickness before the false twisting step, and then feeding the false twisting step and false twisting is considered,
The partially oriented undrawn yarn (POY) of polytrimethylene terephthalate multifilament has a large force for instantaneously recovering the elongation after drawing, so that the yarn feeding tension to the false twisting process also becomes large, causing fluff and yarn breakage. Cheap. After the partially oriented unstretched yarn (POY) is stretched, a relaxation treatment is performed so that the yarn feeding tension to the false twisting process can be reduced.
It becomes possible to stably produce high-quality yarn without fluff without breaking.

The present invention is characterized in that a relaxation step is provided before the false twisting step. In this step, the twisting in the false twisting step is relaxed by a means such as nib gripping so that the twisting is not retroactively performed. In the case of (1), the stretching is performed in a state where the stretching force in the stretching step does not go back and the twist in the false twisting step is not allowed to go back. As a method of relaxation, by making a difference in the roller surface speed between the two sets of gripping rollers constituting the relaxation process, by making the entrance roller surface speed faster than the exit roller surface speed,
The method of relaxing is preferred.

The relaxation conditions are as follows: the yarn feeding tension (tension from the feed roller to the position before the first heater) to the false twisting step subsequent to the relaxation step is 0.01 g / d to 0.1 g / d (d is false twisting). This is the total denier of the yarn to be supplied to the process, and in the case of the draw false twist of the partially oriented undrawn yarn (POY), the total denier of the yarn to be supplied to the false twist through the stretching process and the relaxation process ), Preferably 0.02 g / d to 0.1 g
/ D, more preferably 0.03 g / d to 0.1 g / d
The relaxation rate may be set so as to be in the range of. Specific examples of the relaxation rate include details of the single yarn cross section of the yarn to be supplied to the false twist, the stretch false twist, the amount of the attached oil agent, the total denier, the single yarn. Denier, false twisting method, false twisting conditions, stretching conditions are appropriately set, for example, in the case of false twist, 0.05% to 5%,
Preferably 0.1% to 5%, more preferably 0.1%
3% to 15%, and 3% to 15%, preferably 5% to 12% in the case of partially oriented undrawn yarn (POY).
More preferably, the relaxation rate is in the range of 6% to 10%. Here, the relaxation rate is calculated by the following equation.

Relaxation rate (%) = [(Vin−Vout) / Vin] × 100 Vin: Roller surface speed at the side of the relaxation step Vout: Roller surface velocity at the side of the relaxation step Even if the ambient temperature in the relaxation step is around room temperature All right,
For example, the temperature may be in the range of 10 ° C to 50 ° C. The draw false twist of the partially oriented undrawn yarn (POY) may be stretched to a predetermined thickness before the false twisting step, or, for example, may be stretched to about 50% of a predetermined draw ratio before the false twisting step, After the relaxation treatment, a method in which the film is stretched by about 50% in the false twisting step is also possible.

The heat setting temperature (first heater temperature) during false twisting is 100 ° C. or more and 190 ° C. or less, preferably 100 ° C.
Not less than 170 ° C. and more preferably not less than 120 ° C.
The temperature is preferably set to 0 ° C. or lower. When the heat setting temperature is lower than 100 ° C., crimping is not sufficiently provided, and the heat setting temperature is 190 ° C.
If it is higher than the above range, the strength and elongation are greatly reduced, and the elastic recovery after elongation may be insufficient. When the so-called two-heater false twisting is performed, the second heater temperature is set to about ± 30 ° C. of the first heater temperature, preferably 10 ° C.
The temperature is preferably in the range of 0 ° C. or more and 170 ° C. or less. The feed rate in the first heater and the second heater is +1.
% Or more and not more than + 25%. The heater may be either a contact heater or a non-contact heater, but the second heater is preferably a non-contact heater to avoid uneven heat setting.

The number of false twists may be in a range usually used for false twisting of polyethylene terephthalate multifilament, and the coefficient K of the number of false twists calculated by the following equation is 17600 to 29.
Preferably it is in the range of 500. T (T / m) = K / (denier of false twisted yarn) ^1/2

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to examples and the like, but the present invention is not limited to the examples and the like. The evaluation of the state of false twisting is as follows. ◎: Number of thread breaks 0.1 / day / weight or less ○: Number of thread breaks 1 / day / weight or less △: Number of thread breaks 5 / day / weight or less ×: Number of thread breaks 5 / Day / weight excess XX; Number of thread breaks is 10 times / day / weight or more

[0018]

Example 1 Polytrimethylene terephthalate having ηsp / c = 0.8 was spun at a temperature of 265 ° C. and a spinning speed of 1600 m.
/ Min. To obtain an undrawn yarn, then hot roll temperature 55 ° C., hot plate temperature 140 ° C., draw ratio 2.
63 times, twisting at 800 m / min, 75 d / 3
A 6f drawn yarn was obtained. The strong elongation of the drawn yarn is 4.0 g each.
/ D, 34%. Using a 33H false twisting machine manufactured by Murata Machine Co., Ltd. After passing through the relaxation step under the conditions shown in No. 1, false twisting was performed. Since the yarn feeding tension to the false twisting step was kept low and there was no change in the false twist tension, the obtained false twisted yarn had no fluff and the processing status was ◎.

[0019]

Example 2 Polytrimethylene terephthalate having ηsp / c = 0.8 was spun at 265 ° C., and spun at a speed of 3000 m.
/ Min, and a partially oriented undrawn yarn (POY) of 115d / 36f polytrimethylene terephthalate was obtained. P
The strong elongation of OY was 2.5 g / d and 107%, respectively. Using a 33H false twisting machine manufactured by Murata Machine Co., Ltd., Under the conditions shown in Example 1, a false twisting process was performed in the order of a stretching step, a relaxation step, and a false twisting step. Again, since the yarn feeding tension to the false twisting step was kept low and the false twist tension did not fluctuate, the obtained false twisted yarn had no fluff and the processing status was ◎.

[0020]

Example 3 Using the same POY used in Example 2,
False twisting was performed under the same conditions as in Example 2 except that the relaxation rate was set as low as 3%. Although the yarn feeding tension to the false twisting process was slightly increased, the processing status was ○, and the obtained false twisted yarn did not have fluff.

[0021]

Example 4 Using the same POY used in Example 2,
False twisting was performed under the same conditions as in Example 2 except that the relaxation rate was set as high as 12%. Since the yarn feeding tension to the false twisting step was kept lower, the obtained false twisted yarn did not generate fluff and the processing status was ○.

[0022]

Comparative Example 1 Using the same drawn yarn as used in Example 1,
table. Under the conditions shown in No. 1, false twisting was performed without passing through the relaxation step. Since the yarn feeding tension to the false twisting step was large and the fluctuation of the yarn feeding tension was large, the processability was unstable and the processing status was x.
Moreover, the obtained false twisted yarn had many fluffs.

[0023]

Comparative Example 2 Using the same POY used in Example 2,
table. Under the conditions shown in No. 1, a false twisting process was performed by a method of simultaneously performing a false twist while stretching in a false twisting step without passing through a stretching step and a relaxation step. Since the yarn feeding tension was very large, the workability was unstable and the processing condition was XX. Moreover, the obtained false twisted yarn had many fluffs.

[0024]

Comparative Example 3 Using the same POY used in Example 2,
table. After passing through the stretching step under the conditions shown in No. 1, false twisting was performed without passing through the relaxation step. Since the yarn feeding tension to the false twisting step was very large, the workability was unstable and the processing condition was x.
Further, the obtained false twisted yarn had fluff.

[0025]

[Table 1]

[0026]

According to the method of the present invention, high quality polytrimethylene terephthalate multifilament false twist yarn can be stably produced at a high speed.

Claims (2)

[Claims] 1. A method for producing a false twisted yarn, wherein a relaxation step is provided before the false twisting step in the false twisting of the polytrimethylene terephthalate multifilament. 2. A method for producing a false twisted yarn, comprising the steps of: stretching in a polytrimethylene terephthalate multifilament;