JP2000355828A - Minutely shrinkable polyester filament yarn and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject filament yarn satisfying specific physical properties and capable of giving woven/knitted fabrics with good puffiness, softness and resilience when blended filament yarns are produced using the yarn as a constituent, by treating an undrawn polyester filament yarn or the like at each specific draw ratio, draw temperature and heat-setting temperature. SOLUTION: This filament yarn is obtained by drawing and heat-setting an undrawn or semi-oriented polyester filament yarn at a draw ratio of 1.05-1.20, at a draw temperature of 90-110 deg.C and at a heat-setting temperature of 110-140 deg.C using a drawing machine having at least one pair of hot roller systems. This filament yarn thus obtained simultaneously satisfies the following characteristics: (A) elastic recovery percentage of elongation at 3% elongation is 60-8.5%, (B) boiling water shrinkage is 0-3%, and (C) dry heat shrinkage is equal to or lower than the boiling water shrinkage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyester filament yarn having a low elongation modulus and a low boiling water shrinkage ratio, and a method for producing the same. More specifically, the present invention relates to a finely shrinkable polyester filament yarn capable of providing a woven or knitted fabric excellent in swelling, softness and resilience when used as a mixed fiber.

[0002]

2. Description of the Related Art Polyester filament yarns are widely used in various fields including general garments because of their excellent properties including mechanical properties. In the use of clothing, the quality has been improved by using natural fibers as a target, but various studies have been made to obtain a swelling and soft texture. As one of the means,
Different shrinkage mixed yarns for mixing fibers having different shrinkage characteristics due to heat are widely used. If this type of shrinkage-differentiated yarn is used, a sufficient yarn length difference can be obtained after the dyeing process even if the density of the woven fabric increases, and a fabric excellent in swelling and softness can be obtained. As the yarn on the low shrinkage side of this shrinkage difference mixed yarn, a fiber having an extremely low boiling water shrinkage (hereinafter referred to as a fine shrinkage yarn) or a spontaneously elongated yarn showing extensibility with respect to the yarn before heat treatment during heat treatment is used. The swelling and softness of the fabric is brought out. These finely shrinkable yarns and spontaneously elongated yarns are characterized by having a lower elongation modulus than conventional polyester filament yarns.

A method for producing a spontaneously elongated yarn is described in, for example,
No. 4-352836 discloses a polyester partially oriented yarn (hereinafter referred to as PO).
Y (abbreviated as Y) and a relaxation heat treatment are disclosed in Japanese Patent Application Laid-Open No. 2-93410, and a relaxation heat treatment step is generally required. Further, Japanese Patent Application Laid-Open Nos. 9-228167 and 9-21060 disclose a method using a fixed-length (tensile) heat treatment of POY. However, in these methods, 20
Since a relaxation heat treatment of about 50% is required, process stability is poor, and there is a problem in quality, such as generation of thread spots and dye spots. In addition, the processing speed is slow, the winding during heat treatment, the success rate of processing restart after doff is low, so productivity is low,
Further, a special yarn processing machine capable of relaxation heat treatment was required, and the production cost was high. For this reason, Japanese Patent Application Laid-Open No. 9-273043
Japanese Patent Application Laid-Open Publication No. H11-163,199 proposes a method of obtaining low shrinkage yarn by subjecting POY to contact heat treatment using a hot plate with a low tension, and discloses a manufacturing process diagram of winding the same into a drum shape. However, in order to sufficiently reduce the shrinkage, it is necessary to reduce the yarn tension during heat treatment to 0.12 g / d or less.
In the contact heat treatment using a hot plate, the running of the yarn is not stable due to the abrasion resistance between the running yarn and the hot plate, so that there has been a problem that the yarn spots become large and eventually the yarn breaks. Further, the present invention is different from the winding method of the present invention in that it is wound into a drum shape. Furthermore, since these low shrinkage yarns have a low elongation modulus, the winding method used in the conventional drawing process may cause a change in the quality of the yarn inside the pirn, yarn displacement or breakage due to the change in the winding tension. There are problems such as generation and poor unwinding in higher-order processes. Therefore, in the prior art, it is difficult to obtain a finely shrinkable polyester filament yarn due to instability in quality and high cost.

[0004]

SUMMARY OF THE INVENTION The present invention solves various problems that occur when a polyester filament yarn having a low elongation modulus and a low boiling water shrinkage ratio is produced by relaxation heat treatment and constant-length heat treatment. It does not cause breakage or poor unwinding in high-order processes, has stable productivity with no yarn breakage, and has excellent swelling, softness and resilience when used as a mixed fiber, providing delicate peach touch. An object of the present invention is to obtain a high-quality finely shrinkable polyester filament yarn capable of providing a woven or knitted fabric having the same.

[0005]

The above object can be achieved by a micro-shrinkable polyester filament yarn characterized by simultaneously satisfying the following characteristics.

A. Elongation modulus at 3% elongation is 60% or more and 85% or less.

B. Boiling water shrinkage is 0% or more and 3% or less.

C. The dry heat shrinkage is equal to or less than the boiling water shrinkage.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
As the finely shrinkable polyester filament yarn referred to in the present invention, polyethylene terephthalate (hereinafter abbreviated as PET), polypropylene terephthalate, polybutylene terephthalate, or the like is used as a raw material, but PET is the most general and preferred. Further, a part of the diol component and a part of the acid component may be substituted with another copolymerizable component in a range of 15 mol% or less. However, in the case of polyethylene glycol, the content is preferably 10% by weight or less. They may also contain other polymers and additives such as matting agents, flame retardants, antistatic agents, pigments and the like. Below PE
A method for producing a slightly shrinkable polyester filament yarn using T as a raw material will be described.

The elongation modulus at 3% elongation of the polyester filament yarn obtained in the present invention must be 60 to 85%. Fig. 1 shows the load-
It is an example of an extension curve. The elongation modulus decreases as the residual elongation after elongation increases. In other words, since the low elongation modulus polyester filament yarn has a large residual elongation after elongation, the yarn length can be maintained even after the elongation due to the restraining force at the time of forming a fabric as a differential shrinkage mixed fiber yarn is relaxed by relaxing refining or the like. . This yarn length retention forms a yarn length difference in the shrinkage difference mixed yarn,
It brings out the swelling and softness of the fabric.

If the elongation modulus exceeds 85%, the swelling feeling and the soft feeling when made into a fabric will be insufficient. Also,
Less than 60% means that the fiber structure is loose, resulting in reduced dimensional stability. Also, in the manufacturing process, the running of the yarn becomes extremely unstable, and stable production is difficult.

The boiling water shrinkage of the slightly shrinkable polyester filament yarn obtained in the present invention is essential to be 0% or more and 3% or less, and improves the swelling feeling and the soft feeling when made into a fabric. For this purpose, the content is preferably 0% or more and 1% or less. If the boiling water shrinkage ratio is higher than 3%, when the fabric is made, the swelling feeling and the soft feeling are insufficient. On the other hand, when the boiling water shrinkage is lower than 0%, the elongation modulus is 60%.
As in the case of less than 1, the dimensional stability is reduced, and the running of the yarn in the manufacturing process becomes extremely unstable.

The dry heat shrinkage of the slightly shrinkable polyester filament yarn obtained in the present invention must be equal to or less than the boiling water shrinkage. When the dry heat shrinkage ratio is greater than the boiling water shrinkage ratio, the crimp and yarn length difference formed by relaxing refining of the fabric are reduced by heat treatment in a higher-order processing step such as an intermediate setting, and the swelling and softness of the fabric are reduced. Will be insufficient.

[0014] The fineness of the finely shrinkable polyester filament yarn obtained in the present invention is from a fineness of about 0.2 d to 5
A fineness of about d can be arbitrarily adopted, but it is preferable that the fineness of a single yarn be 1.0d or less, since a fine peach touch can be imparted to the fabric. Also,
The cross-sectional shape of the filament yarn adopts a multi-leaf cross-section such as a tri-lobal cross-section in order to obtain a dry feeling and luster other than a round cross-section,
It is also possible to adopt a hollow cross section or the like in order to obtain a lightweight feeling. Further, in the case where the single yarn fineness is extremely small, it is preferable to impart entanglement to the filament yarn in order to prevent yarn breakage and fuzz generation in the high-order processing step. In addition, in order to mix and entangle with a highly shrinkable polyester filament yarn to obtain a shrinkage difference mixed yarn, the degree of entanglement of the filament yarn is 2
It is preferably set to 0 or less.

FIG. 2 is a schematic view of a stretching and heat treatment step showing a preferred embodiment of the present invention. The undrawn yarn or the partially oriented yarn 1 is wound around the first hot roll 3 and the separate roll 4 several times via the feed roll 2 and preheated,
It is stretched at a predetermined magnification between the first hot roll 3 and the second hot roll 5 and heat-treated by the second hot roll 5 to be a drawn yarn. Next, it is wound as a pan 10 by a traveler 9 sliding on a ring 8 traversing in the vertical direction through a stretch roll 6 and a lappet guide 7 that are not heated.

In the method for producing a slightly shrinkable polyester filament yarn of the present invention, an undrawn polyester yarn or a partially oriented yarn of a polyester filament yarn is drawn at a draw ratio of 1.05 using a drawing machine having at least one pair of hot roller systems. ~
It is important to perform stretching and heat setting at 1.20, a stretching temperature of 90 to 110 ° C., and a heat setting temperature of 110 to 140 ° C. By performing the heat setting with a drawing machine having a hot roller, the yarn path during the heat setting is stabilized, and the yarn breakage is reduced, so that the process stability is greatly improved.

In the present invention, the draw ratio is set to 1.05 to 1.2.
Must be 0 times. If the draw ratio is lower than 1.05, the sway of the yarn on the hot roller increases, the running of the yarn is not stabilized, uniform quality cannot be obtained, and the yarn breaks. On the other hand, if the stretching ratio exceeds 1.20, distortion due to stretching cannot be suppressed, and it becomes difficult to reduce the boiling water shrinkage.

In the present invention, temperature conditions during stretching and heat setting are important. In the present invention, the drawing temperature refers to the preheating temperature of the yarn immediately before drawing, and in the embodiment of FIG. 2, refers to the first hot roll temperature immediately before drawing. In the present invention, the stretching temperature needs to be 90 ° C. or more and 110 ° C. or less. When the stretching temperature is 90 ° C. or higher, the mobility of molecular chains is sufficiently improved before stretching, and it is possible to suppress yarn spots due to uneven stretching. In addition, P before stretching
Excessive crystallization of OY is prevented, which is advantageous for reducing shrinkage.

In the present invention, the heat setting temperature means the heat treatment temperature of the drawn yarn, and in the embodiment of FIG. 2, it refers to the temperature of the second hot roller after the drawing. In the present invention, the heat setting temperature needs to be 110 ° C. or more and 140 ° C. or less. By setting the heat setting temperature to 110 ° C. or higher, the crystallization of the drawn yarn proceeds sufficiently, fixing the oriented amorphous molecular chains becomes sufficient, and it is advantageous for reducing the shrinkage. Yarn shaking becomes large, resulting in poor heat setting.

Further, according to the production method of the present invention, when winding as a pan, the number of rotations of the pan during winding (hereinafter, referred to as "pan").
Spindle rotation speed) is controlled at any time from the start of winding to the end of winding, the traveler used is optimized, and the winding tension from the winding start to the winding end is ± The content is preferably within 20%, so that the low elongation modulus fiber can be stably produced with uniform quality and without occurrence of package collapse or unwinding failure in a high-order process. In order to further improve the uniformity of quality and the unwinding property, it is more preferable to set the winding tension to within ± 10% of the winding tension at the start of winding.

The winding tension is ± 2 with respect to the winding tension at the beginning of winding.
When it is within the range of 0%, the uniformity of quality becomes good, and the unwinding property becomes good at the time of unwinding in a higher-order process.

As a means for keeping the winding tension within ± 20% of the winding tension from the beginning of winding to the end of winding, the spindle rotation speed is set according to the elapsed time from the start of winding. It is effective to suppress the fluctuation of the winding tension. It is also effective to optimize the traveler to be used according to the fineness of the low elongation modulus polyester filament yarn in order to suppress the quality change from the start to the end of winding.

With a normal polyester filament yarn having an elongation modulus of 95% to 100%, winding is performed while temporarily reducing the winding tension in order to prevent buckling in a high-order process and improve unwinding properties. I have. Further, the temporary decrease in the winding tension from the start of winding to the end of winding is about 50 to 70% of the winding tension at the start of winding. As the winding tension decreases and the pan diameter increases, the spindle rotation speed also decreases toward the end of winding.

In the winding method of the present invention, the number of spindle rotations at the start and end of winding is reduced for a while, however, the local increase in the winding tension due to the non-constant increase in the pan diameter during winding. In order to keep the winding tension at the start of winding within ± 20%, including a slight increase, the spindle rotation speed is set according to the winding time. Further, the winding tension at the start of winding is preferably 0.08 to 0.12 g / d in order to suppress a change in quality due to the winding tension. Is preferably 60 to 80 °.

[0025]

EXAMPLES The present invention will be described more specifically with reference to the following examples. In addition, the following methods were used for the measurement method and the evaluation method in the examples. Table 3 shows the measurement results and the evaluation results. A. Elongation modulus Using ORIENTEO's RTC1210A, the initial sample length was set to 20 mm and the pulling speed was set to 2 mm / min.
The elongation modulus (%) at 3% elongation was determined according to the IS L1013 A method. B. Entanglement degree ENTANGLEMENT- manufactured by ROTHSCHILD
Using a TESTER, the pre-tension was set to 0.1 g / d, the trip tension was set to (pre-tension + (number of drawn yarns / number of filaments)) g, the sample supply speed was set to 4 cm / sec, and the entangling distance was measured 50 times. Using the values, the degree of confounding was calculated by the following equation.

Degree of confounding = 1000 / Average value of confounding distance Pan hardness HARDNESS TESTER "Ty"
The center of the pan was measured using "pe C". D. Winding tension and width of fluctuation of winding tension The winding tension was measured by using a tension checker CB manufactured by Kanai Koki Co., Ltd. to measure the running yarn tension on the wrappet guide. Then, recording was continuously performed during winding by a TYPE 30472 2-pen recorder manufactured by Yokogawa Electric Corporation.

The winding tension fluctuation range was calculated by the following equation using the winding tension at the start of winding and the maximum and minimum values of the winding tension.

ΔTmax = (Tmax−Ts) / Ts ΔTmin = (Tmin−Ts) / Ts ΔTmax: maximum value (%) of the winding tension fluctuation width ΔTmin: minimum value (%) of the winding tension fluctuation width Ts: winding E. Initial winding tension (g) Tmax: Maximum winding tension (g) Tmin: Minimum winding tension (g) Evaluation of uniformity of quality in the pan A standard deviation of the boiling water shrinkage in the longitudinal direction of the yarn was used as a scale for evaluating the uniformity of the quality in the pan.
Continuous measurement of the boiling water shrinkage in the yarn longitudinal direction of the low shrinkage yarn was performed using FTA-500 manufactured by Toray Engineering Co., Ltd. At this time, the yarn supply speed was 20 m / min, and the running yarn stress was 0.
The solution was passed through a wet heat treatment apparatus heated to 100 ° C. at 1 g / d and having a length of 15.5 cm. Then, the measurement was performed for 10 minutes, and the standard deviation of the shrinkage rate was obtained. At this time, the raw shrinkage was taken in as point data for every 3.3 cm of the measured yarn length, and these were combined into six points and averaged to obtain one data. Then, 1000 pieces of the data were collected, the standard deviation was calculated, and 0.25 or less was regarded as a pass. F. Package foam evaluation The package foam of the rolled-up pan was visually observed, and the degree of occurrence of yarn layer shift and package collapse was evaluated. The evaluation methods were as follows: ：: yarn layer displacement, no package collapse, Δ: thread layer deviation leading to occurrence of unwinding failure, ×: package collapse occurrence, and ○ passed. G. FIG. Evaluation of unwinding property The yarn was unwound from the pirn at an unwinding speed of 600 m / min, and the degree of occurrence of wheel slippage or poor unwinding was observed to evaluate the unwinding property. H. Fabric Evaluation The low elongation modulus polyester filament yarns obtained in Examples and Comparative Examples were 30 denier, 12 filament high shrinkage homopolymers having a boiling water shrinkage of 21.5% and a dry heat shrinkage of 19.5%. Air mixed using polyester filament yarn and interlace nozzle to produce shrinkage differential mixed yarn,
This was S-twisted at 300 turns / m and plain woven. This was subjected to relaxation smelting at 98 ° C., and intermediately set at 180 ° C. Further, the alkali was reduced by 10% by weight according to a conventional method, dyed, and finished at 180 ° C.
Regarding the cloth obtained by the above method, the feeling of swelling and the feeling of softness were organoleptically evaluated on the 1st to 5th grades, and the 3rd or higher grade was accepted. Example 1 Using antimony trioxide as a polymerization catalyst, polyethylene terephthalate (PET) having an intrinsic viscosity (measured in an oxochlorophenol solvent at 25 ° C.) of 0.65 was obtained from terephthalic acid and ethylene glycol according to a conventional method. At this time, 0.4 wt% of titanium oxide having an average primary particle size of 0.5 μm was added as a matting agent. The obtained polymer is melt-spun at a spinning temperature of 284 ° C. and a spinning speed of 2500 m / min.
The 56.7 denier 36 filament POY was wound up.

The POY was stretched using a stretching machine having a pair of hot rollers as shown in FIG. 2 with the temperature of the first hot roller 3 at 95 ° C., the temperature of the second hot roller 5 at 125 ° C., and the stretching speed of 970 m / min. The draw ratio was set as shown in Table 1 to obtain a drawn yarn. The obtained slightly shrinkable polyester filament yarn was a finely shrinkable polyester filament yarn having uniform quality. The cloth made of the differential shrinkage mixed fiber obtained from the polyester filament yarn had excellent swelling and softness. Comparative Example 1 A yarn was produced under the same conditions as in Example 1 except that the draw ratio was set as shown in Table 1 (Experiment Nos. 4 and 5). Experiment No. with a stretching ratio of 1.25 times. In No. 4, the elongation modulus, the boiling water shrinkage, and the dry heat shrinkage were all high, and the fabric evaluation lacked a swelling feeling and a soft feeling.
Experiment No. 1 in which the stretching ratio was 1.02 times. In No. 5, the elongation modulus and the boiling water shrinkage ratio were lower than the ranges of the present invention, the fiber structure was loose, and the dimensional stability was lowered, so that the package collapsed and the fabric could not be evaluated. Also,
The standard deviation of the shrinkage ratio was as large as 0.42, and the polyester filament yarn had a large variation in quality.

[0030]

[Table 1] Example 2 Example 1 except that the POY fineness was 136.5 denier, the number of filaments was 144 and 192, the stretching ratio was 1.14 times, the stretching temperature was 100 ° C., and the heat setting temperature was 130 ° C. Spinning under the same conditions as in
A drawn yarn of 44 filaments and 120 denier 192 filaments was obtained (Experiment Nos. 6 and 7). The fabric obtained from the differential shrinkage mixed yarn using the obtained polyester filament yarn was excellent in swelling and softness, and also excellent in handleability. In particular, since the single-fiber fineness was 1.0 d or less, the fabric had a delicate peach touch. Example 3 A yarn was produced in the same manner as in Example 1 except that the draw ratio was changed to 1.14 times and the heat setting temperature was changed as shown in Table 2, to obtain a drawn yarn of 50 denier and 36 filaments (Experiment Nos. 8 to 10). 1
0). When the heat setting temperature is 110 to 140 ° C., the elongation modulus, boiling water shrinkage, and dry heat shrinkage fall within the range of the present invention, and the standard deviation of shrinkage is 0.17 or less, and uniform quality is obtained. The fabric obtained from the shrinkable polyester filament yarn, which is a shrinkage-differential mixed fiber, had excellent swelling and softness. Comparative Example 2 A yarn was drawn in the same manner as in Example 1 except that the draw ratio was changed to 1.14 times and the heat setting temperature was changed as shown in Table 2, to obtain a drawn yarn of 50 denier and 36 filaments (Experiment No. 11,
12). Experiment No. 1 in which the heat setting temperature was 105 ° C. 11
Had insufficient boiling water shrinkage. Further, the fabric obtained from the shrinkage difference mixed yarn using the obtained polyester filament yarn lacked a swelling feeling and a soft feeling. Experiment No. 1 in which the heat setting temperature was 145 ° C. 12
Was a spontaneously elongated yarn having a boiling water shrinkage of -0.3%, a large standard deviation of shrinkage of 0.37, and a polyester filament yarn having a large variation in quality. In addition, the running state of the yarn was unstable, and the winding of the yarn occurred on a hot roll or a stretch roll, and it was not possible to obtain an amount of stretched yarn necessary for evaluating the fabric.

[0031]

[Table 2] Example 4 A yarn was produced in the same manner as in Example 1 except that the draw ratio was changed to 1.14 times, the heat setting temperature was changed to 130 ° C., and the draw temperature was changed as shown in Table 3, to obtain a drawn yarn having 50 denier and 36 filaments. (Experiment Nos. 13 and 14). Stretching temperature is 90-110
At 0 ° C., the elongation modulus, boiling water shrinkage, and dry heat shrinkage fall within the range of the present invention, and the standard deviation of the shrinkage is 0.18 or less, and the finely shrinkable polyester filament yarn having uniform quality. Could be obtained. Further, the fabric obtained from the shrinkage difference mixed yarn using the obtained polyester filament yarn was excellent in swelling feeling and soft feeling. Comparative Example 3 A yarn was produced in the same manner as in Example 1 except that the draw ratio was changed to 1.14 times, the heat setting temperature was changed to 130 ° C., and the draw temperature was changed as shown in Table 6, to obtain a drawn yarn having 50 denier and 36 filaments. (Experiment Nos. 15, 16). Experiment No. 1 in which the stretching temperature was 85 ° C. No. 15 was a polyester filament yarn having a large standard deviation of the shrinkage ratio of 0.41 due to insufficient preheating immediately before stretching, and a large variation in quality. Experiment No. 1 in which the stretching temperature was 115 ° C. No. 16 was a polyester filament yarn having a large standard deviation of shrinkage of 0.38 and a large variation in quality.

[0032]

[Table 3] Example 5 Using antimony trioxide as a polymerization catalyst, polyethylene terephthalate (PET) having an intrinsic viscosity (measured in an oxochlorophenol solvent at 25 ° C.) of 0.65 was obtained from terephthalic acid and ethylene glycol according to a conventional method. At this time, 0.4 wt% of titanium oxide having an average primary particle size of 0.5 μm was added as a matting agent. The obtained polymer is melt-spun at a spinning temperature of 284 ° C. and a spinning speed of 2500 m / min.
The 136.5 denier 48 filament POY was wound up.

Using a stretching machine having a pair of hot rollers as shown in FIG. 2, the temperature of the first hot roller 3 is set to 100 ° C., the temperature of the second hot roller 5 is set to 130 ° C., and the stretching ratio is set to 1.14. The stretching speed was set to 970 m / min, the traveler was # 23 manufactured by Kanai Kiko Kogyo Co., Ltd., and the spindle rotation speed was set as shown in Table 4. 120 denier 4%
An 8-filament low elongation modulus polyester filament yarn was obtained. If the fluctuation range of the winding tension is within the range of ± 20%, the standard deviation of the boiling water shrinkage rate is 0.18 or less, uniform quality, and yarn layer misalignment, package collapse, and unwinding failure also occur. Did not. In the evaluation of the cloth, a cloth excellent in swelling feeling and soft feeling was obtained (Experiment No. 17).
19). When the winding tension fluctuation range is out of the range of ± 20%, sinkage or slab-like defects in the fabric due to a decrease in unwinding property due to a yarn layer shift and a variation in shrinkage rate occurred (Experiment No. 1).
20-22).

[0034]

[Table 4]

[0035]

[Table 5]

[0036]

EFFECT OF THE INVENTION By using the finely shrinkable polyester filament yarn of the present invention, problems in the production process and poor dimensional stability, which were conventionally encountered with spontaneously elongated yarn, are improved, and the feeling of swelling and softness is excellent. The present invention can provide a slightly shrinkable polyester filament yarn for producing a polished polyester fabric.

[Brief description of the drawings]

FIG. 1 shows an example of a load-elongation curve at the time of elongation elastic modulus measurement.

FIG. 2 is a schematic view of a stretching and heat treatment step showing an embodiment of the present invention.

[Explanation of symbols]

 1. 1. Undrawn yarn or partially oriented yarn Feed roll 3. First hot roll 4. Separate roll 5. Second hot roll 6. Stretch roll 7. Lappet guide 8. Ring 9. Traveler 10. Pan

Claims (4)

[Claims] 1. A finely shrinkable polyester filament yarn which simultaneously satisfies the following characteristics. (1) The elongation modulus at 3% elongation is 60% or more and 85% or less. (2) The boiling water shrinkage is 0% or more and 3% or less. (3) The dry heat shrinkage is equal to or less than the boiling water shrinkage. 2. The single yarn fineness is 1.0d or less, and the entanglement degree is 20
The slightly shrinkable polyester filament yarn according to claim 1, wherein: 3. An unstretched or partially oriented yarn of a polyester filament yarn is stretched and heat-set by a stretching machine having at least one pair of hot roller systems. A method for producing a slightly shrinkable polyester filament yarn, wherein the heat setting temperature is 110 ° C or more and 140 ° C or less. 4. When winding a slightly shrinkable polyester filament yarn as a pirn following drawing, the winding tension is within ± 20% of the winding tension at the start of winding from the start of winding to the end of winding. The method for producing a slightly shrinkable polyester filament yarn according to claim 3, wherein the yarn is wound.