JPH0770860A - Fiber cluster - Google Patents

Abstract

PURPOSE:To obtain a fiber cluster having nearly same degree of natural and good stretchability and elasticity-recovering property as natural fiber and forming a napped part of lightweight napped fabric having bulkiness, swelling, antidrape stiffness and handle and good appearance and touchiness. CONSTITUTION:This fiber cluster consists of a polyester-based monofilament having twist number of 5-200/inch and 0.05-0.80 modified cross-section ratio, and the porosity between these fibers is 15-60%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber assembly having high elasticity. The napped cloth having the napped part of the fiber assembly has a soft touch and a deep color tone, and is lightweight and excellent in durability.

[0002]

2. Description of the Related Art Upstanding fabrics such as cut pile, moquette, double russel, velour, and velvet have various appearances and textures, and interiors such as car seats, carpets and flocked fabrics; It has a wide range of applications such as clothing. However, the napped cloth whose napped part is made of polyester fiber has a harder touch than acrylic, nylon, rayon, cotton, wool and the like, and is remarkably inferior in appearance such as gloss and luster. Further, since the polyester fiber has a large difference in refractive index between the fiber side surface and the fiber cross section, if hair fall of the napped portion or spiral crimp occurs, the degree of reflection or transmission of light,
The glossiness is different, streaks, finger marks, darkening,
Gloss difference such as white blur and color difference are likely to occur. Furthermore, the bulge,
The polyester fiber is much inferior to the natural fiber in the elasticity, the feel of the waist, and the feel of the waist.

Superior properties of a napped fabric made of natural fibers in the napped part, such as beam, waist, bulge, elasticity, black spots and white blurring, are used in the napped part of polyester fiber. Various methods have heretofore been proposed in order to apply the napped fabric obtained from the above. For example, as a bileaflet type composite fiber in which a polymer having a relatively high shrinkage property and a polymer having a low shrinkage property are bonded in a side-by-side type, it is possible to generate twist in a yarn.
No. 287,810 is proposed. However, the twist that develops in the bileaflet-type composite fibers that are bonded side-by-side becomes spiral, and the hair ends curl,
Since the fiber side surface appears on the surface of the napped fabric, light is diffusely reflected,
A whitish streak occurs. In addition, the bilobed conjugate fiber having a flat cross-section bonded side-by-side does not cause streaking, but is not satisfactory in terms of hair collapse, color depth, and the like.

Further, in order to reduce the difference in gloss and color in the napped fabric and to reduce streaks, hand marks, darkening, white blurring, etc., a core-sheath type in which inorganic fine particles having a high refractive index are contained only in the sheath portion A composite fiber (JP-A-1-306648) and a core-sheath composite taper fiber having fine irregularities formed on the fiber side surface (JP-A-4-21412) have been proposed. However, the napped woven or knitted fabric using the former composite fiber for the napped portion has a round fiber cross section, and the napped hair is straight-haired, so that the difference in gloss and color difference is observed, but the elasticity and swelling are increased. However, in the case of the napped woven or knitted fabric using the latter composite fiber in the napped portion, there is a problem of so-called fibrillation reduction, in which the recessed portion is cracked due to uneven conditions.

[0005]

DISCLOSURE OF THE INVENTION The object of the present invention is to have almost the same natural and good stretchability and elastic recovery as natural fiber, and to have bulkiness, bulge, beam, and a chewy appearance and feel. Another object of the present invention is to provide a fiber assembly that forms a raised portion of a favorable lightweight raised fabric.

[0006]

That is, the present invention provides 5
A fiber aggregate having a twist number of 200 to 200 pieces / inch and a degree of deformation of 0.05 to 0.80, and having a porosity of 15 to 60%. is there.

The polyester monofilament should have a twist number of 5 to 200 fibers / inch, preferably 10 to 100 fibers / inch. When the number of twists is less than 5, the woven or knitted fabric having the fiber bundles as naps lacks the bulge and the texture deteriorates. On the other hand, when the number of twists exceeds 200, the fibers are greatly shrunk, and when a napped woven or knitted fabric using the fibers in the napped part is swollen and stretchable, the waist is lost and the napped part falls down. , The whole napped part is hard and is not satisfactory in terms of texture.

The polyester monofilament according to the present invention has a degree of deformation of 0.05 to 0.8 in its cross-sectional shape.
It must be 0, preferably 0.10 to 0.60. The degree of irregularity is a value represented by the following formula.

Deformation degree = R / L As shown in FIG. 1, in the fiber cross section, L is the length AB of the line connecting the adjacent tip portions A and B, and R is located in the middle of the adjacent tip portions. It is the length CD of the perpendicular line from the dent D to the line connecting the adjacent tip portions A and B.

When the degree of irregularity is less than 0.05, the unevenness of the fiber cross-sectional shape becomes small and the gloss cannot be made mellow. Further, a napped woven or knitted fabric in which the fibers are used for the napped part has poor napped property such as falling of the napped part, resulting in insufficient bulging and fiber density. On the other hand, the degree of irregularity is 0.80
If it exceeds the range, the unevenness becomes large, that is, if the constricted part is formed too deep, not only the manufacturing situation of the fiber becomes difficult, but also such fiber is easily damaged in the processing process such as twisting process. The problem of fibrillation arises. The irregularity in the present invention does not change between the spun raw yarn and the drawn yarn.

As a cross-sectional shape of the fiber having the above-mentioned irregularity, for example, the one shown in FIG. 2 can be mentioned. 2 (a) to (h) show a central portion 1 made of a thermoplastic polymer A extending in the fiber axial direction, and a central portion 1 surrounding the central portion 1 and connected to the central portion in the fiber axial direction. It is a composite fiber composed of three or more protruding portions 2 extending. Although the number of the projecting portions 2 is 3 to 5 in (a) to (h) of FIG. 2, the number of the projecting portions may be any number as long as it satisfies the above-mentioned deformation degree. Not limited to. Although a composite fiber composed of two or more components is shown in FIG. 2, in the present invention, the composite fiber does not have to be a composite fiber and may be a fiber composed of a single polymer.

The composite fiber shown in FIG. 2 is composed of a central portion extending in the axial direction of the fiber and three or more protrusions extending in the axial direction of the fiber provided around the central portion and connected to the central portion. A fiber having a leaf cross section. As these fibers,
For example, the central portion is composed of a thermoplastic polymer A having a heat shrinkage stress of 0.3 g / denier or more and a heat shrinkage rate of 15% or more, and at least a part of each protrusion is a thermoplastic polymer. A composite fiber composed of a thermoplastic polymer B having a heat shrinkage smaller than A can be mentioned. In the present invention, as long as the fiber satisfies the above-mentioned twist number and the degree of irregularity, it is not limited to the polymer constituting the fiber, and as described above, in addition to the composite fiber, a single polymer. It may be a fiber composed of-. Hereinafter, the conjugate fiber using the above-mentioned thermoplastic polymers A and B will be described in detail.

As the thermoplastic polymer A, any fiber-forming thermoplastic polymer having a heat shrinkage stress of 0.3 g / denier or more and a heat shrinkage rate of 15% or more can be used, but especially, A polyester having a heat shrinkage stress of 0.3 g / denier or more and a heat shrinkage rate of 15% or more is preferable. The polyester is selected from aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and aliphatic dicarboxylic acids such as azelaic acid and sebacic acid.
At least one dicarboxylic acid component, ethylene glycol,
Aliphatic diol such as 1,4-butanediol, aromatic diol such as bisphenol A or bisphenol S ethylene oxide adduct diol, and cycloaliphatic diol such as cyclohexane dimethanol. Examples thereof include polyesters formed by using a diol component such as diol and, if necessary, a hydroxycarboxylic acid component such as p-hydroxybenzoic acid. Even with the same polyester, the heat shrinkage stress and the heat shrinkage can be increased or decreased by adjusting the intrinsic viscosity, the type and ratio of the copolymerization component, and the like. In order to prevent the texture of the napped woven or knitted fabric in which the composite fiber using the thermoplastic polymer A is napped, the heat shrinkage stress of the polymer A is 0.3 to 0.7 g / Denny
And the heat shrinkage rate is preferably in the range of 15 to 50%.

As the thermoplastic polymer B, any fiber-forming thermoplastic polymer having a heat shrinkage smaller than that of the thermoplastic polymer A can be used. For example, polyamides such as nylon 6, nylon 66, nylon 610, nylon 11, nylon 12 and nylon 13, which have a smaller heat shrinkage than the thermoplastic polymer A, polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate. -, Or polyesters formed by copolymerizing 5-sodium sulfoisophthalic acid thereof. If the thermoplastic polymer B has a smaller heat shrinkage ratio than the thermoplastic polymer A, the heat shrinkage stress thereof may be the same as that of the thermoplastic polymer A or may be larger than that of the thermoplastic polymer A. Further, the thermoplastic polymer A and the thermoplastic polymer B may be the same kind of polymer or different kinds of polymer.

Thermoplastic Polymer A and Thermoplastic Polymer B
Is selected and combined with those having good properties such as compatibility and laminating / bonding property so that they can be maintained in a composite form without being separated during processes such as spinning, drawing, post-processing, and napped knitting process. It is preferable. In order to impart appropriate elasticity and bulge to the napped knitted fabric, the difference in the heat shrinkage ratio between both components is 5 to 2
It is preferably in the range of 5%. If the difference is outside this range, the texture of the napped knitted fabric may be poor.

The composite ratio of the thermoplastic polymer A and the thermoplastic polymer B is preferably 20/80 to 80/20 by weight. In the multi-lobed fiber shown in FIG. 2, it is preferable that the thermoplastic polymer A constitutes the central portion and the thermoplastic polymer B constitutes at least a part of the projecting portion, but at least the tip of the projecting portion. It is preferable that the portion is composed of the thermoplastic polymer B in order to have the twist number defined in the present invention. As described above, the fiber according to the present invention may be composed of a single polymer, and these thermoplastic polymers A or B may be used alone. In that case, by adopting appropriate spinning / drawing conditions, a fiber assembly having the target performance can be obtained.

The above-mentioned composite fiber can be produced by melt-compositing a thermoplastic polymer A and a thermoplastic polymer B, and then preferably stretching (drawing / heat setting) and heat treatment. In that case, even if a method is adopted in which spinning is carried out at a normal spinning speed of 1000 to 4000 m / min, cooling is performed, winding is performed while supplying oil if necessary, and then stretching and heat treatment are performed at an appropriate temperature, high-speed spinning is performed. A method may be adopted in which a fiber is produced at the same time as spinning by using a method and then heat-treated, or a spinning direct-coupling method in which fiber is directly stretched and then heat-treated. In any case, if the difference in melt viscosity between the thermoplastic polymer A and the thermoplastic polymer B is extremely large, it is easy to cause kneeling in the spinneret, and the spinning processability may be deteriorated. It is preferred to select both polymers with different viscosity differences.

Further, the drawing temperature and heat setting temperature adopted in the drawing process of the composite fiber are factors which often directly affect the stretchability, bulge and the like of the composite fiber and the napped woven or knitted fabric using the composite fiber as the nap. Therefore, when performing the stretching treatment, it is necessary to pay sufficient attention to the stretching temperature and the heat setting temperature. In particular, of the thermoplastic polymer A and the thermoplastic polymer B, the polymer having a higher glass transition temperature (Tg) is stretched at a temperature of Tg or higher, so that the processability, the finished napped knitted fabric and the quality are improved. Is preferred. In addition, the tension applied during drawing is preferably low in order to develop twist in the composite fiber.

Further, the heat treatment carried out after the stretching may be carried out either continuously with the stretching treatment or as an independent step separately from the stretching treatment. The heat treatment may be performed after the fibers or the yarns of about 1000 to 3000 denier are combined, and when finishing the napped knitted fabric or at the time of subsequent dyeing.
It may be performed at any time during the finishing process.

The composite fiber composed of thermoplastic polymer A and thermoplastic polymer B having different heat shrinkage rates is shown in FIG.
As seen in (a) to (h), a thermoplastic polymer A having a large heat shrinkage ratio is located at the center of the cross section of the fiber cross-sectional shape, and a thermoplastic polymer having a small heat shrinkage ratio is located around it.
Since B is located, the thermoplastic polymer A in the center part only contracts, and the thermoplastic polymer B in the periphery part has a frill-like shape due to the difference in the heat contraction rate from the thermoplastic polymer A in the center part. Twist is expressed, and the fiber becomes a state in which several frills are present around one fiber. The heat shrinkage rate of the composite fiber is preferably in the range of 10 to 40%. If the heat shrinkage ratio is less than 10%, twisting may not occur and the napped knitted fabric may not bulge. On the other hand, if the heat shrinkage ratio exceeds 40%, the napped knitted fabric may shrink, resulting in fluffiness and flexibility. Is lost, and the appearance and texture may be deteriorated, which is not preferable.

The fiber bundle having such a form has a porosity of 15
-60%. When the porosity is less than 15%,
The napped woven or knitted fabric having the fiber bundle as napped fibers is the same as the conventional synthetic fiber napped woven fabric in terms of weight saving and softness.
If the porosity exceeds 60%, the weight of the woven or knitted material can be expected to be reduced, but the elasticity and durability are poor, and the soft feeling, suppleness, and other feelings are insufficient.

The napped knitted fabric in which such fibers are napped does not cause the napped parts to fall, slant, or wavy, and is fine denier and bulky even at low density. Despite the tension, it is soft and supple. Also,
Since the tips of the hairs are upright, light is uniformly absorbed between the fibers, and a fluffy woven or knitted fabric having a streak-free deep color is obtained. Furthermore, it has excellent straightness and durability.

A woven or knitted fabric having a nap is a woven or knitted fabric composed of ground yarn (ground yarn) and pile yarn (raised yarn) such as moquette, double russel, velour, velvet and cut pile. -Widely used for interiors such as shoes, carpets, flocked cloth, artificial suede, clothes, etc. When using the fiber assembly of the present invention in a napped product,
The nap length is 10 mm or less, and the nap density is 7 × 10 ↑ 3 to 8 ×
The range of 10 ↑ 6 lines / cm ↑ 2 is preferable. Further, the napped portion of the napped product does not have to be composed of only the fiber aggregate, and may be used as a part.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. In addition, each physical property in an Example was measured by the following method.

(1) Intrinsic viscosity of polymer [η] It is a value measured at 30 ° C. by dissolving the polymer in a mixed solvent of phenol / tetrachloroethane (weight ratio 1: 1).

(2) Heat shrinkage stress of thermoplastic polymer A Using thermoplastic polymer A alone, under the same conditions and under the same conditions as in the production of the conjugate fiber in each example, the same cross-sectional shape and dimensions. Then, a modified cross-section fiber having a thickness is spun and drawn, the obtained drawn yarn is collected for 10 cm, and both ends are connected to form a loop. Using an autograph ("AG-2000A type" manufactured by Shimadzu Corporation), 0.5 g / denier
Dry heat treatment is performed at a rate of 1 ° C / min from room temperature under the load of the reel, and the maximum shrinkage stress (g) at that time is read, divided by the total fineness of the yarn, and the heat shrinkage per single fineness The stress (g / denier) was determined.

(3) Heat Shrinkage (%) of Thermoplastic Polymer Using the thermoplastic polymer alone, using the same apparatus as in the production of the conjugate fiber in each example, under the same conditions and under the same cross-sectional shape, A modified cross-section fiber having a size and a thickness is spun and drawn, and the obtained drawn yarn is collected by 50 cm. A load of 100 mg / denier is applied to one end of the drawn drawn yarn, and the length L ↓ 0 (cm) of the drawn yarn at that time is measured. Then,
By changing the load applied to the drawn yarn to 1 mg / denier,
It is immersed in boiling water for 20 minutes, then taken out and air dried. The load applied to the drawn yarn was changed to 100 mg / denier, the length L ↓ 1 (cm) of the drawn yarn at that time was measured, and the heat shrinkage rate was calculated by the following mathematical formula.

Thermal shrinkage (%) = {(L ↓ 0-L ↓ 1) /
L ↓ 0} × 100

(4) Heat shrinkage rate (%) of conjugate fiber The drawn yarn of the conjugate fiber obtained in each example was sampled and subjected to 100% in the same manner as the measurement of the heat shrinkage rate of the thermoplastic polymer.
Length of drawn yarn when load is applied to mg / denier L ↓
0 (cm), and the load applied to the drawn yarn was changed to 1 mg / denier, and after soaking this in boiling water for 20 minutes,
Take it out and let it air dry, and apply a load of 100 mg to the drawn yarn.
/ Length of drawn yarn when changed to denier L ↓ 1 (c
m) was measured and determined by the above formula.

(5) Number of twists of conjugate fiber (pieces / inch) The bundle of drawn yarns of the conjugate fiber obtained in each example is skein-shaped and immersed in boiling water for 30 minutes, then heat-treated and air-dried, The crimped state of the single yarn was maintained almost as it was, and the single yarn was attached to a slide glass one by one in the length direction, and the number of twists within a length of 1 inch was visually counted. that time,
The point where the protrusions to the left and right intersect with each other along the length direction of the fiber is counted as one.

(6) Cross-sectional shape of conjugate fiber The quality of the cross-sectional shape of the conjugate fiber obtained by the following four-step evaluation criteria was evaluated. ⊚: The shape is good, and the composite form and shape are not uneven. ◯: There is some unevenness in the composite form and shape, but there is no problem. Δ: The shape is a little bad and variation occurs. X: The shape is bad, and the unevenness in the composite form and fineness is large.

(7) Porosity (%) of fiber assembly Twisted yarn in which three yarns are aligned and undertwisted at 2500 T / M, three yarns are combined and S400T / M is overtwisted An optical micrograph of a fiber cross section cut with a microtome was taken. The photograph was enlarged and cut into fibers and voids, and the porosity was determined by the weight ratio. Void (%) = (weight of void) x 100 / (weight of fiber +
Void weight)

(8) Deformation degree of fiber An optical micrograph of a fiber cross section was taken and measured and calculated by the above method.

(9) State of napped part The state of the napped part was evaluated according to the following three-stage evaluation criteria. ⊚: Good straight hair property, moderate flexibility, waist and durability. ◯: Straight hair and streak are acceptable levels, but flexibility and durability are slightly inferior. X: Bristles are bent, streaks are present, and they are rough and poor.

(10) Color of the napped knitted fabric The color of the napped woven knitted fabric was evaluated according to the following three-stage evaluation criteria. ⊚: The color tone is uniform, deep, and moist and calm. ◯: Pass level in terms of color uniformity and depth. X: There are color spots, white blur and black spots are seen, and the appearance is inferior.

Example 1 As the thermoplastic polymer A, polybutylene terephthalate (PBT) having [η] = 1.1, heat shrinkage stress of 0.35 g / denier and heat shrinkage of 20% was used. As the thermoplastic polymer B, [η] = 0.68 and the heat shrinkage rate is 7%.
Polyethylene terephthalate (PET)
The ratio of BT: PET = 1: 1 (weight ratio) was supplied to the spinning device, spun, and wound at a take-up speed of 1000 m / min to obtain a cross-sectional shape of 200 denier / 36 filaments as shown in FIG. ) Like three branch type composite fiber (spun raw yarn) was obtained.
The degree of irregularity was 0.10. The two spinning yarns obtained above are put together, a heating roller at a temperature of 75 ° C, and a pre-roller at a temperature of 120 ° C.
150 denier by stretching (stretching and heat setting)
A 72 filament drawn yarn was obtained. The number of twists of this drawn yarn and the porosity of the fiber assembly were measured and found to be 32 yarns / inch, 33%. 3m long with this thread as the nap
m double raschel knitted fabric was prepared, and heat set, dyed, and finished.

When the tip of the napped portion of this napped knit was observed under a microscope, the tips of the naps were upright. The napped knit had a soft feel, and it had a waist despite having a bulge.
In addition, the appearance was dark and had a deep and subdued hue, and was excellent in lightness.

Example 2 As a thermoplastic polymer A, [η] = 0.76, a heat shrinkage stress of 0.35 g / denier and a heat shrinkage of 18.
Spinning was carried out in the same manner as in Example 1 except that PET in which 8% by mole of 0% isophthalic acid was copolymerized was used to obtain a four-branched composite fiber (spun raw yarn) as shown in FIG. The degree of variation is 0.
It was 32. This spun raw yarn was treated in the same manner as in Example 1 to obtain a drawn yarn. Table 2 shows the twist number of the drawn yarn and the porosity of the fiber bundle. Use this thread as a nap,
Create a double Russell knit with a length of 3 mm, heat set,
Dyeing and finishing were performed. When the tip of the napped portion of this napped knit was observed with a microscope, the hair tips were upright.
The napped knit had a soft feel, and it had a waist despite having a bulge. In addition, the appearance was dark and had a deep and subdued hue, and was excellent in lightness.

Example 3 PET containing 12 mol% of isophthalic acid having [η] = 0.82 as the thermoplastic polymer A and having a heat shrinkage stress of 0.47 g / denier and a heat shrinkage of 35%. Spinning was carried out in the same manner as in Example 1 except that was used to obtain a composite fiber (spun raw yarn) having a cross-sectional shape shown in FIG. The degree of irregularity was 0.30. Then, it is drawn, and the number of twists of the drawn yarn and the porosity of the fiber assembly are shown in Table 2. 3m long with this thread as the nap
m double raschel knitted fabric was prepared, and heat set, dyed, and finished. When the tip of the napped portion of this napped knit was observed with a microscope, the hair tips were upright. The napped knit had a soft feel, and it had a waist despite having a bulge. In addition, the appearance was dark and had a deep and subdued hue, and was excellent in lightness.

Examples 4 to 7 Spinning was carried out in the same manner as in Example 1 using the polymers shown in the table.
It was drawn to obtain a drawn yarn. Table 2 shows the degree of fiber irregularity, the number of twists of the drawn yarn, and the porosity of the fiber assembly. These threads,
A double Russell knitted fabric having a length of 3 mm was prepared as a napped portion, and heat set, dyed, and finished. When the tips of the napped portions of these napped knits were observed with a microscope, the tips of the naps were upright. The napped knit had a soft feel, and it had a waist despite having a bulge. In addition, the appearance was dark and had a deep and subdued hue, and was excellent in lightness.

Example 8 Spinning was performed using only PET having [η] = 0.75 and a heat shrinkage rate of 15% to obtain a fiber having a cross-sectional shape shown in FIG. 75 ° C heating roller, 110 ° C pre-roller
Was stretched (stretched and heat set) at a stretch ratio of 75% of the cutting stretch ratio. The number of twists of the drawn yarn was 25 / inch. Using this yarn, a napped knitted fabric was prepared in the same manner as in Example 1, and the tip of the napped portion was observed with a microscope. As a result, the hair tips were upright. The napped knit had a soft feel, and it had a waist despite having a bulge. In addition, the appearance was dark and had a deep and subdued hue, and was excellent in lightness.

Comparative Examples 1 to 3 [η] = 0.68, heat shrinkage stress 0.2 g / denier, and heat shrinkage 7% PET only (Comparative Example 1), [η] = 0.5
5, PET having a thermal shrinkage of 5% only (Comparative Example 2), [η] =
Only polybutylene terephthalate having a heat shrinkage of 0.70, a heat shrinkage stress of 0.23 g / denier and a heat shrinkage of 9% (Comparative Example 3) was used, and spinning was performed under the same conditions as in Example 1, and the results shown in FIG. A fiber (spun raw yarn) having a cross-sectional shape of (2) was obtained. Then, it was stretched.
The irregularity of each fiber, the number of twists of the drawn yarn, and the porosity of the fiber assembly are shown in Table 2. Using these yarns, a napped knitted fabric similar to that of Example 1 was prepared, but the napped portion had no stiffness. , The depth of color was insufficient, and the product value was low. In the napped knitted fabric obtained in Comparative Example 2, the number of twists of the fibers constituting the knitted fabric is 3 /
The size was inch, the degree of irregularity was 0.02, and the gap between the stitches was noticeable. Further, the napped knitted fabric obtained in Comparative Example 3 had a poor cross-sectional shape of the fibers constituting the knitted fabric, had a low degree of irregularity, and was extremely inferior in terms of lightness.

Comparative Example 4 Spinning was carried out in the same manner as in Example 1 using the polymers shown in the table.
It was drawn to obtain a drawn yarn having a cross-sectional shape shown in FIG.
Table 2 shows the degree of fiber irregularity, the number of twists of the drawn yarn, and the porosity of the fiber assembly. The fiber cross-sectional shape was somewhat poor. When a napped knitted fabric similar to that of Example 1 was prepared using this drawn yarn, the napped part was shrunk because the fibers constituting the napped knitted fabric had too many twists, resulting in a hard and stiff feel. Met. In addition, the appearance and color had many spots, streaks were seen, and the quality was poor.

Comparative Example 5 Spinning was carried out in the same manner as in Example 1 using the polymers shown in the table.
It was drawn to obtain a drawn yarn having a cross-sectional shape shown in FIG. The fiber cross-sectional shape was good, but the degree of irregularity was as low as 0.04. When a napped knitted fabric similar to that of Example 1 was prepared using this drawn yarn, the number of twists of the fibers constituting the napped knitted fabric was within the range of the present invention, but the fiber irregularity was small, and thus the napped knitted fabric was obtained. Lacked in bulge, poor appearance and color, and poor quality.

Comparative Example 6 A yarn having a round cross section was spun at a speed of 1000 m / min using only PET in which 8 mol% of isophthalic acid was copolymerized. The obtained spun raw yarn was drawn, and a nap knitted fabric was prepared using the drawn yarn, but it had no characteristics at all and was very inferior to polyester-like.

[0046]

[Table 1]

[0047]

[Table 2]

[0048]

The napped woven or knitted fabric having the fiber assembly of the present invention as the napped portion has straight hair swelling, swelling, flexibility and durability, and has a deep color. Furthermore, since the fiber assembly of the present invention has an appropriate amount of voids, it also leads to weight reduction of the napped knitted fabric.

[Brief description of drawings]

FIG. 1 is a diagram showing the degree of irregularity of fibers constituting a fiber assembly of the present invention.

FIG. 2 is a diagram showing an example of a cross-sectional structure of fibers constituting the fiber assembly of the present invention, and FIGS. 2 (A) to 2 (H) are all one mode thereof.

FIG. 3 is a fiber cross-sectional structure shown as a comparative example.

[Explanation of symbols]

 A: Thermoplastic polymer-A B: Thermoplastic polymer-B 1: Central part 2: Projection part 3: Connection part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masao Kawamoto 1621 Sakata, Kurashiki City, Okayama Prefecture Kuraray Co., Ltd.

Claims (3)

[Claims] 1. A twist number of 5 to 200 pieces / inch, 0.0
An aggregate composed of polyester single fibers having a degree of irregularity of 5 to 0.80, wherein the porosity between the fibers is 15 to 60.
% Fiber aggregate. 2. A fiber assembly, wherein the polyester single fiber is composed of two or more kinds of polymers having different heat shrinkage rates. 3. A napped fabric in which a fiber assembly forms a napped portion.