JPH081014B2 - Method for producing latent bulky polyester composite yarns for woven and knitted fabrics - Google Patents

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 composite yarn for a silk-like woven or knitted fabric, which is soft and flexible, has a dry touch, and has suitable beam, waist and drape properties.

[0002]

2. Description of the Related Art Up to now, polyester multifilaments have been used for various purposes such as clothing and industrial materials by taking advantage of their excellent characteristics. As a clothing use, silk-like texture is being investigated by each company as one of the targets, and in some fields, a characteristic texture that surpasses silk is obtained. For example, composite yarns composed of a plurality of multifilaments having different heat shrinkage properties are widely used because they exhibit excellent properties such as bulge, bulkiness, and warmth, and feel. However, when all of the multifilaments that make up the yarn shrink due to heat, the difference in shrinkage ratio of the yarn cannot be secured due to the binding force of the structure of the knitted fabric, and the knitted fabric becomes hard due to the shrinkage of the yarn. For this reason, measures such as reducing the basis weight to allow a shrinkage allowance and increasing the alkali reduction rate to secure the texture have been implemented. However, a filament having a large heat shrinkage is generally cured by heat treatment, and a satisfactory texture surface has not been obtained. On the other hand, a mixed yarn of a polyester filament which is elongated by heat treatment and a filament which is contracted by heat treatment is also known, for example, JP-A-55-62240, JP-A-56-112537, and JP-A-60-2.
No. 8515 is available. Although these yarns are much softer and softer than those of the above-mentioned shrink yarns, they have a slimy feel due to the loops of elongated and protruding filaments, and a large difference in yarn length due to heat treatment. Since it was expressed, the yarn was separated, and there was a problem in handleability in the subsequent process.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks of polyester filaments, and has softness, flexibility, elegant dry touch, moderate beam, waist, and drapeability, and a post-process. It is an object of the present invention to provide a novel method for producing a polyester composite yarn, which has no problem in passage property.

[0004]

The present invention has the following structure in order to solve such problems. That is, spinning speed 15
The elongation at break obtained by stretching the undrawn yarn spun at 00 to 4000 m / min at a glass transition temperature or higher is 30 to 45.
%, Δn 0.10 to 0.14 polyester multifilament drawn yarn with a non-contact heater at a heater temperature T (° C.) that satisfies the following formulas (1) and (2) of the formula [A] and 20 Polyester multifilament A satisfying the following formula [B] was obtained by subjecting it to relax heat treatment at an overfeed rate of -60%
A with a polyester multifilament B that satisfies the formula
/ B = 20 to 80% / 80 to 20% (denier ratio), and a entanglement treatment with a degree of entanglement of 20 to 100 co / m. It is a manufacturing method. The spinning speed refers to the spinning winding speed. [A] 75 log {(D × Vy) ^1/2 /HL}+4.7
(Vy) ^1/2 ≧ T ≧ 25 log {(D × Vy) ^1/2 /HL}+4.7
(Vy) ^1/2 (1) T≤Tm-10 (2) D: Denier after relaxation Vy: Relax take-up roller speed (m / min) HL: Relax non-contact heater length (m) Tm: Melting point ( C) Tg: Second-order transition temperature (C) [B] SHW (A) ≧ 0%, SHD (A) ≦ 0% SHW (B) ≧ 0% SHD (B) −SHD (A) ≧ 5% DE (A) ≧ 50% SHW: Hot water (100 ° C.) shrinkage rate (%) SHD: Dry heat (160 ° C.) shrinkage rate (%) DE: Breaking elongation (%)

A method for producing the polyester composite yarn of the present invention will be described. A schematic side view of the apparatus for producing a polyester composite yarn of the present invention is illustrated in FIG. In order to produce a polyester multifilament A having excellent spontaneous stretchability, first, an unstretched yarn spun at a spinning speed of 1500 to 4000 m / min is stretched at a stretching temperature of Tg to Tg + 20 ° C. and a breaking elongation of 30 to 45% after stretching. n may be stretched in the range of 0.10 to 0.14. A spinning speed of less than 1500 m to min is not preferable because the physical properties after stretching are unstable and the thickness unevenness becomes large. On the other hand, if it exceeds 4000 m / min, the heat shrinkage rate after stretching becomes low and the spontaneous stretchability becomes low, so that the texture of the woven or knitted fabric does not become a predetermined feeling. Preferably 2000-4
000 m / min. The stretching temperature is preferably Tg or higher for stretching stability, and at a temperature of Tg + 20 ° C. or higher, crystallization progresses and spontaneous stretchability decreases. Further, the drawing temperature is important for the expression of spontaneous elongation, but in view of operability such as yarn breakage during drawing, the elongation at break must be 30% or more. When the elongation at break is 45% or more, yarn unevenness is observed, which is not preferable. In addition, Δn needs to be in the range of 0.10 to 0.14, and outside this range, the stability of spontaneous elongation due to the relaxation heat treatment is lacking. Next, the relaxation heat treatment by the non-contact type heater that gives spontaneous elongation is performed by the heater temperature T satisfying the following expressions (1) and (2) at the same time.
(C) and the overfeed rate of 20 to 60% are required. 75 log {(D × Vy) ^1/2 /HL}+4.7 (Vy
) ^1/2 ≥ T ≥ 25 log {(D x Vy) ^{1/2 /} HL} + 4.7 (Vy
) ^1/2 (1) T ≦ Tm-10 (2) D: Denier after relaxation Vy: Relax take-up roller speed (m / min) HL: Relax non-contact heater length (m) Tm: Melting point (° C.) Tg: Second-order transition temperature (° C.) The present inventors found the relationship of the equation (1) with respect to the spontaneous elongation of the heater temperature, the denier and the relaxation treatment rate, and the length of the non-contact heater. If it is higher than the range of formula (1), spontaneous elongation is lowered due to progress of crystallization,
If it is low, the spontaneous elongation is weakly expressed. Also (1)
It is necessary to satisfy both equation (2) and equation (2) at the same time, but if the heater temperature is (Tm-10) ° C or higher, the multifilament will melt during the stop inside the heater due to the heat of the heater when the doffing is stopped, and The startability is reduced and it cannot be used industrially. In addition, relax transaction roller speed V
The y is preferably 10 to 1500 m / min, and the relaxed non-contact heater length HL is preferably 0.1 to 2 m.

The overfeed rate is 20 to 60 in order to exhibit spontaneous elongation and stabilize the operability of the relaxation heat treatment.
% Is good. It is necessary to use a non-contact heater as the heater because a contact type heater has a shortage of yarn tension at the heater inlet due to running resistance of the multi-filament and roller winding and yarn breakage occur. The polyester multifilament A is entangled with a polyester multifilament different from the polyester multifilament A so as to have a denier ratio of 20 to 80% / 80 to 20% and an entanglement degree of 20 to 100 co / m. Here, the different polyester multifilament is, for example, SHW. S
A material having at least one different heat shrink property such as HD.

Dyeing and setting processing is performed, and due to the difference in yarn length,
The polyester multifilament B component may have a boiling water shrinkage of 5% or more and a 160 ° C. dry heat shrinkage of 7% or more in order to obtain a woven or knitted fabric having good bulge, tension, waist and bulkiness. If both are lower than the above range, a sufficient yarn length difference cannot be obtained, and a woven or knitted fabric having a good feel cannot be obtained. The boiling water shrinkage is preferably 5 to 60%, and the 160 ° C dry heat shrinkage is preferably 7 to 80%. Of course, the polyester multifilament may be so-called thick and thin yarn or spontaneously stretchable yarn, but in the former case, the hot water shrinkage rate is 5 to 30%, and in the latter case, the 160 ° C dry heat shrinkage rate is 0%. It is sufficient that the elongation difference with the multifilament A is at least 5%.

It is also important to mix and weave so that the denier ratio becomes 20 to 80%, and if the spontaneously extensible polyester multifilament is less than 20%, the bulge and bulkiness are insufficient, and if it exceeds 80%, the tension is increased. , Will be stiff. The degree of entanglement is 20 to 100 / in order to obtain twisting, warping, handleability in weaving, and uniform appearance in a woven or knitted fabric.
It must be m. When it is 20 co / m or less, the polyester multifilament A and the polyester multifilament B are easily separated from each other, and the handling property in the next step is deteriorated. If it exceeds 100 k / m, a woven or knitted product cannot have a uniform appearance. With the above configuration, it is possible to obtain a composite yarn of polyester multifilament A and polyester multifilament B excellent in handleability, expression of spontaneous elongation and productivity.

Next, the composite yarn obtained by the manufacturing method of the present invention will be described. FIG. 2 is a model diagram after the polyester composite yarn of the present invention is heat-treated to develop a yarn length difference. In FIG. 2, A is a multifilament that mainly constitutes the sheath portion and is substantially elongated by the high temperature heat treatment (multifilament after spontaneous elongation). B is a multifilament that constitutes the core portion, and is a multifilament contracted by heat treatment (multifilament after heat contraction). First, the heat shrinkage property of the constituent multifilament, which is the most important requirement in the present invention, will be described. The multifilament A constituting the polyester composite yarn of the present invention shows a small difference in shrinkage rate from the multifilament B in a usual process such as sizing, and substantially exhibits shrinkage behavior. Therefore, even when the same yarn length difference is expressed in the fabric, even when sizing at the yarn stage, the yarn length difference (bulges, loops, etc.) does not appear so much, and even compared with the normal all-shrink heterogeneous mixed yarns. During weaving, the handling and weaving properties are much better. That is, when a yarn length difference (loop) appears in the yarn state, it is natural that beaming,
During weaving, the loops rub against each other, catching on guides, combs, etc., and the opening becomes poor, resulting in a marked decrease in process passability. Furthermore, when heat treatment is applied to ordinary heat-shrinkable multifilaments, the heat setting is almost fixed, and even if the heat treatment is performed at a high temperature of 160 to 180 ° C in the final set, the difference in yarn length is much longer than that at the first heat setting. Although it does not develop, like the composite yarn of the present invention, it contains multifilaments that shrink in hot water but expand in high-temperature heat treatment corresponding to the final set, so that multi-filament is produced by finishing at a temperature higher than the shrinked fabric surface. The filament A protrudes like a loop, and a soft and soft touch is obtained as if it were the surface of peach. Therefore, SHW (A) ≧ 0% and SHD (A) ≦ 0% are sufficient. SH for further bulge and bulkiness
D (B) -SHD (A) ≧ 5% is suitable, and if it is less than 5%, it swells and the bulkiness is poor, so it is excluded from the present invention. However, if it is too large, the protruding loop from the surface becomes too large, and problems such as "shining" tend to occur when ironing, so 50% or less is preferable. For the same reason, SHW
(A) is preferably 5% or less, and SHD (A) is preferably -15% or more. Next, the breaking elongation of the multifilament A is 50% or more in order to obtain a soft and soft texture. Generally, in polyester, in order to obtain a soft feeling, the SHW of the filament is small and the breaking elongation is easily obtained. As described in detail above, it is the spontaneously extending multifilament that covers the surface of the fabric by forming a loop.
This is because the touch of the multifilament determines the touch of the cloth. However, if the elongation at break is too large, the handling property becomes poor, so 100% or less, more preferably 80%.
% Or less is good.

Next, the breaking elongation of the multifilament B is 4
It is preferably 0% or less, because yarn unevenness due to stretching of the composite yarn in a post-process such as winding and knitting or weaving does not occur. Further, it is for preventing a problem such as the removal of a knee in the product after forming the cloth. Also, the breaking strength of the composite yarn depends substantially on the heat-shrinking multifilament, and therefore the breaking strength of the heat-shrinking multifilament must be at least 4 g / denier and 20% or more in terms of the denier ratio of the composite yarn. Of course, if the breaking strength is high, the ratio of the multifilament B may be slightly low, but if it is less than 20%, the shrinkage force of the multifilament B becomes small and the bulge due to the difference in the yarn length is not expressed, so it is excluded from the present invention. still,
The hot water shrinkage and the 160 ° C. dry heat shrinkage of the multifilament B are preferably 5 to 60% and 7 to 80%, respectively.

Further, a so-called thick and thin yarn having uneven thickness in the fiber axis direction of the multifilament B may be used. However, in that case, the hot water shrinkage may be 5 to 30%. The thick and thin yarn has a degree of orientation (Δn) of 1 at the thin portion in terms of maintaining the physical properties of the yarn after post-processing.
5 to 60 × 10 ⁻³ or more, more preferably 160 × 10
^-3 or more is good. Generally, when a thick and thin yarn is dyed, a difference in shade is exhibited, but there is a drawback in that the difference in shade is too strong. However, the mixed woven yarn of the present invention is heat treated to give the thick and thin yarn in the inner layer portion and the multifilament A. Is arranged in the outer layer portion, and the excessively strong shade difference of the thick and thin yarn is moderately covered by the multifilament A yarn, resulting in a natural color difference.

Next, the multifilament A must be composed of a single yarn denier of 3 denier or less.
If it exceeds 3 denier, the elongation at break is large and the texture becomes coarse and hard even if the Young's modulus is low, so it is excluded from the present invention.
However, if it becomes too thin, even filaments having a modified cross-section, which will be described later, become tense and lose stiffness, so 0.2 denier or more is preferable. However, 3 denier or more may be mixed (denier mix), and 3 denier or less may be averaged. Furthermore, the filament preferably has a modified cross section having at least one recess on the outer peripheral surface of the cross section. In particular, a filament having a large breaking elongation, such as the composite yarn of the present invention, is soft but tends to have a slimy feel. Therefore, by making the cross-sectional shape different, the number of point contact portions between filaments increases, resulting in a dry touch. . The irregular cross-section as used herein refers to a cross-sectional shape such as a triangle, a hexagon, a flat shape, or a hollow thereof having at least one recess on the outer peripheral surface of the cross section. As shown in FIG. Further, in order to provide such a feeling and effect, it is preferable to consist of 10 or more filaments of these single yarns.

Next, the reason why this composite yarn has a substantially core / sheath structure is that the multifilament A is present in a large amount in the surface layer portion of the composite yarn, so that the loop easily projects from the surface of the fabric. Further, the term "substantially having a core / sheath structure" as used herein means only a structure in which a composite yarn is divided into a core portion and a sheath portion, that is, a multifilament B and a multifilament A at a certain interface. Rather, both components are mixed in the entire composite yarn particularly near the boundary surface, which means a structure in which the multifilament B is mainly arranged in the core part and the multifilament A is mainly arranged in the sheath part, Within the radius 1/3 from the center of the composite yarn, the multifilament B is larger than the multifilament A in weight ratio, and within the radius 1/3 from the surface of the composite yarn, the multifilament A is larger than the multifilament B. It is within the scope of the invention.
The core / sheath structure and the above-mentioned denier ratio are measured by fixing the composite yarn with an epoxy resin and randomly cutting a section 100 times and observing it with an optical microscope to obtain the average value and state. It is also essential that they are entangled with a degree of entanglement of 20 to 100. When the degree of entanglement is less than 20, multifilaments are entangled, and when entangled, the yarns are likely to separate due to the difference in yarn length, which significantly impairs the process passability. Conversely, the degree of confounding is 1
If it exceeds 00, interlaced spots are conspicuous on the fabric, and the monofilaments of the multifilament A may be cut and become fluff, which is not preferable.

Next, the cross section of the multifilament B constituting the inner layer portion is not particularly limited, but the cross section of the multifilament B is the same as that of the multifilament A in order to further enhance the dry hand, in order to give bulkiness. A modified cross-section yarn having at least one recess on the outer peripheral surface is also preferable. Further, the polyester composite yarn of the present invention has a multifilament A
If necessary, a polyester fiber containing a copolymer of 5-sodium sulfonic acid metal salt, isophthalic acid or the like or a fine powder inactive substance may be contained in either or both of the component and the multifilament B component.

Next, it is preferable that the present composite yarn is in a twisted state. However, if the yarn is twisted too much, a difference in yarn length is less likely to occur, so 15000 / (D) ^1/2 (T / m) or less is preferable, but it is not necessarily limited to this when softness and flexibility are not required.

The constitutions and effects of the present invention will be explained with reference to the following examples, but the present invention is not limited by the following examples.

[0017]

EXAMPLES The measuring methods carried out in the present invention are as follows.

(1) Elongation at break In accordance with JIS-L-1013 (1981), using Tensilon manufactured by Toyo Baldwin Co., Ltd., sample length (gauge length) 2
The S-S curve was measured at 00 mm and a pulling speed of 200 mm / min to calculate the breaking elongation.

(2) Heat Shrinkage (SHW), Dry Heat Shrinkage (SHD) According to JIS-L-1073, the following was obtained. That is, with a lap reel with an appropriate frame circumference, 8 with an initial load of 1/10 g / denier
The wound roll is removed, a load of 1/30 g / denier is applied to the roll, and the length L ₀ (mm) is measured. Then, the load is removed, and the skein is immersed in boiling water for 30 minutes while applying a load of 1/1000 g / denier. After that, the case is taken out of the boiling water, and after cooling, a load of 1/30 g denier is applied again and the length L ₁ (mm) at that time is measured. Then, after drying at 60 ° C for 30 minutes, 1/1000 g /
Heat treatment is performed in an oven having a dry heat of 160 ° C. under a denier load. Then, after cooling, a load of 1/30 g / denier is applied again, and the length L ₂ (mm) at that time is measured. The hot water shrinkage rate (SHW) and the dry heat shrinkage rate (SHD) are calculated by the following equations. SHW = (L ₀ −L ₁ ) × 100 ÷ L ₀ SHD (L ₀ −L ₂ ) × 100 ÷ L ₀

(3) Degree of entanglement A thread of an appropriate length is taken out and vertically suspended by applying a load of 1/10 g / denier to the lower end. Then, an appropriate needle is put into the thread, and the distance L (cm) that is slowly lifted and the load is lifted is measured 100 times. From this, an average value L (cm) is calculated and calculated by the following formula. Entanglement degree = 100 ÷ (2 × L)

Examples 1 to 3 Comparative Examples 1 to 8 Normal polyester as a heat-expandable multifilament is stretched at a spinning winding speed of 3000 m / min by a conventional method. Denier after relaxation-DE, SHW, SHD are shown in Table 1 as physical properties. As shown in FIG. 1, the spinning discharge amount, the draw ratio, the relaxation rate, the relaxing temperature, and the set time were changed, and the heat-shrinkable multifilament was commercial Toyobo Co., Ltd. Machined. Here, as the air nozzle 7, an air jet FG-1 manufactured by Fiber Guide was used, and the air pressure and the feed ratio between the feed roller 6 and the delivery roller 8 were adjusted so that the target degree of entanglement could be obtained. The physical properties of the raw yarn used, the yarn quality of the obtained composite yarn, and the yarn were subjected to a sizing step after twisting by a usual method, and then the texture of the woven fabric dyed and finished with decin was judged. Further, as the process passability, in particular, twisted yarn, rewinding, and weaving property were determined, and comprehensive determinations in terms of process passability and feeling are shown in Tables 1 to 3, respectively. Examples 1 and 2 had good feeling and process passability within the scope of the present invention. Comparative Example 1 is a heat-expanded multifilament SH
A loop was generated even when sizing when W was negative (expanded by heat), and the opening was poor even in weaving, and there was a problem in process passability. In Comparative Example 2, the heat-expandable multifilament did not shrink and there was no protruding loop on the surface of the fabric, and the ordinary heterogeneous-shrink mixed fiber was obtained only with the same feel. In Comparative Example 3, the elongation at break of the heat-extended multifilament is as low as 40%, so the surface touch is
It was a little rough and not good. In Comparative Example 4, since the breaking elongation of the heat-shrinkable multifilament was as high as 50%, the breaking elongation of the composite yarn was also large and unevenness due to tension was generated, and puckering was also generated on the cloth. In Comparative Example 5, since the ratio of the heat-shrinkable multifilament (ratio to the composite yarn denier) is as low as 18%, the strength of the composite yarn is low and the yarn breakage occurs.
The texture was good, and I was not satisfied with it. On the contrary, in Comparative Example 6, since the heat shrink filament ratio was as large as 90%, there were few heat shrink filaments protruding to the surface of the fabric, and the bulge and bulkiness were inferior.
In Comparative Example 7, since the degree of entanglement was low, the yarn was separated and the process passability was poor. In Comparative Example 8, since the degree of entanglement was as high as 130, moire spots called interlaced marks were generated on the cloth.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

[Table 3]

D: Total denier Fil: Number of filaments Cross-sectional shape: △ Triangular cross-section of Fig. 3, 1 ○ Round cross-section Fabric texture: 4-step evaluation by tactile sensory evaluation by 10 persons ◎ Soft feeling, elasticity, waist, drape feeling All are good ○ Lack of softness △ Lack of softness and drape × Roughness Process passability: Loom operating rate ◎ 98% or more ○ 95% or more △ 90% or more × less than 90% Overall judgment: Fabric texture Judgment of process passability ◎ Both are good △ Either one or both have defects × Either one or both are very bad

Examples 3 to 7 and Comparative Examples 9 to 17 Intrinsic viscosity of 0.63 polyethylene terephthalate was changed by a conventional method using a spinning nozzle having 18 holes to change the spinning speed and discharge rate to obtain undrawn yarns in Table 4. It was Subsequently, a mixed yarn was prepared under the conditions shown in Tables 5 and 6, and weaving and dyeing were performed by usual methods. During this period, as the process passability, stretching operability, relax heat treatment operability, post-processing passability such as weaving, and evaluation results of the texture and appearance of the fabric are also shown in Tables 5 and 6. For the preparation of the mixed fiber, the drawing, relaxing and mixing machine shown in FIG. 1 was used. For the adjustment of the degree of entanglement, an air jet FG-1 manufactured by Fever Guide was used, and the air pressure and the processing tension were adjusted. Examples 3 to 7 were excellent in process passability, woven and woven fabric appearance, and texture within the scope of the present invention. Comparative Example 9
Has a lower stretching temperature than the glass transition temperature (about 70 ° C),
The drawing operability was poor, and the appearance of the woven fabric was also poor. In Comparative Examples 10 and 11, the breaking elongation after stretching is outside the scope of the present invention, and in Comparative Example 10, the breaking elongation after stretching is high, uneven thickness is observed during stretching, and the texture and the appearance of the fabric are uniform. I was not satisfied with the feeling. Further, in Comparative Example 11, the breaking elongation after stretching was low and Δn was outside the scope of the present invention, but the stretching operability was poor and the process passability was also reduced accordingly. In Comparative Examples 12 and 13, the relax heat treatment temperature was outside the scope of the present invention, and in Comparative Example 12, the relax heat treatment temperature was low and the spontaneous stretchability was lacking, and the fabric texture was not satisfactory. In Comparative Example 13, the relaxation heat treatment temperature was high, fusible yarn breakage occurred when the doffing was stopped, and the texture of the fabric was slightly unsatisfactory. In Comparative Examples 14 and 15, the overfeed rate during the relaxation heat treatment was outside the scope of the present invention, and Comparative Example 14
The texture was not satisfactory due to lack of spontaneous elongation. In Comparative Example 15, the overfeed rate was high, the relaxation heat treatment operability was deteriorated, and moreover, there were many loops in the mixed fiber and the post-processability and the texture of the woven fabric were poor. In Comparative Examples 16 and 17, the mixed fiber denier ratio of the spontaneously extensible multifilament and the heat-treatable multifilament is outside the scope of the present invention, and in Comparative Example 16, the ratio of the heat-shrinkable multifilament is high and the woven fabric lacks softness there were.
Further, in Comparative Example 17, the ratio of heat-shrinkable multifilaments was low, and the elasticity was lacking.

[0027]

[Table 4]

[0028]

[Table 5]

[0029]

[Table 6]

Den: Total denier fil: Number of filaments ◎ ○ △ × Stretching operability: Stretching thread cutting rate 2% or less 5% or less 10% or less 11% or more Relaxing operability: Relaxing thread cutting rate 2% or less 5% or less 10 % Or less 11% or more Post-process passability: Loom operation rate 98% or more 95% or more 90% or more and less than 90% Woven texture: Tactile feel by 10 people 4-level evaluation by sensory evaluation ◎ Soft feeling, tension, waist, drape feeling are all Good ○ Lack of softness △ Lack of softness and drape × Rugged Appearance: Irritation, streak, and other defects of the fabric were evaluated in 4 levels by a tester ◎ None ○ Slightly noticeable △ Conspicuous × Remarkably conspicuous Total: Comprehensive judgment of process operability / passability and fabric texture / appearance ◎ All good △ Some defects × Some very bad

[0031]

As described above, the polyester composite yarn of the present invention is softer and more flexible than the conventional hetero-shrink mixed fiber yarn (including heat-extended yarn), and has a dry touch and an appropriate tension, waist,
It has a remarkable effect of having drapeability and excellent process passability.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an example of a manufacturing apparatus according to the present invention.

FIG. 2 is a side view in which the composite yarn obtained by the present invention is heat-treated to develop a yarn length difference.

FIG. 3 is a typical example of a cross-sectional shape of a filament single yarn in the present invention.

[Explanation of symbols]

 A: Heat-expandable multifilament B: Heat-shrinkable multifilament C: Polyester composite yarn of the present invention 3: Hot roller 5: Non-contact heater 7: Air jet nozzle

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location D02G 3/34 D02J 1/00 K

Claims (1)

[Claims] 1. A polyester multi having a breaking elongation of 30 to 45% and a Δn of 0.10 to 0.14 obtained by drawing an undrawn yarn spun at a spinning speed of 1500 to 4000 m / min at a glass transition temperature or higher. The filament drawn yarn is subjected to a relaxation heat treatment with a non-contact heater at a heater temperature T (° C.) satisfying the following formulas (1) and (2) at the same time and an overfeed rate of 20 to 60%, thus obtained. A polyester multifilament A satisfying the following formula [B] and a polyester multifilament B satisfying the following formula [B] are A / B = 20 to 80% / 80 to 20%
The degree of entanglement is 20 to 10 according to the (denier ratio).
A process for producing a latent bulky polyester composite yarn for a woven or knitted fabric, which comprises performing an entanglement treatment at 0 k / m. [A] 75 log {(D × Vy) ^1/2 /HL}+4.7
(Vy) ^1/2 ≧ T ≧ 25 log {(D × Vy) ^1/2 /HL}+4.7
(Vy) ^1/2 (1) T≤Tm-10 (2) D: Denier after relaxation Vy: Relax take-up roller speed (m / min) HL: Relax non-contact heater length (m) Tm: Melting point ( C) Tg: Second-order transition temperature (C) [B] SHW (A) ≧ 0%, SHD (A) ≦ 0% SHW (B) ≧ 0% SHD (B) −SHD (A) ≧ 5% DE (A) ≧ 50% SHW: Hot water (100 ° C.) shrinkage rate (%) SHD: Dry heat (160 ° C.) shrinkage rate (%) DE: Breaking elongation (%)