EP2980288A1

EP2980288A1 - Spun yarn and woven or knitted fabric

Info

Publication number: EP2980288A1
Application number: EP14775600.1A
Authority: EP
Inventors: Masahiro TANINOMIYA; Teruhiko KASAHARA; Michiaki CHIBA; Shunma MIYAUCHI
Original assignee: Toray Industries Inc
Current assignee: Toray Industries Inc
Priority date: 2013-03-27
Filing date: 2014-02-27
Publication date: 2016-02-03
Anticipated expiration: 2034-02-27
Also published as: JPWO2014156451A1; EP2980288B1; KR20150137067A; JP6332024B2; WO2014156451A1; CN105051275B; CN105051275A; EP2980288A4; US20160076173A1; SA515361234B1

Abstract

[Problem] To provide: a spun yarn which has not only a soft texture but also functions that cannot be attained by a natural or cellulose-based fiber alone, namely high water absorption, quick drying property and non-see-through property, and which is suitable for clothing, particularly for inner shirts or sport shirts; and a woven or knitted fabric comprising the same. [Solution] A mixed spun yarn which comprises 20 to 80 mass% of a polyester-based fiber having a flat multi-lobe section and 20 to 80 mass% of a cellulose-based fiber, wherein: the cross section of the polyester-based fiber has a flat shape which has six or more protrusions on the circumference; and the flatness degree and modification degree of the cross section are prescribed.

Description

Technical Field

The present invention relates to a spun yarn having good water absorbability, quick drying properties and anti-transparent properties and soft touch feeling, and particularly, relates to a spun yarn which makes it possible to obtain a woven or knitted fabric suitable for clothing uses, for example, uses for inner shirts, pants, sports shirts and the like and a woven or knitted fabric using the same.

Background Art

For clothing uses such as uses for inner shirts, pants and sports shirts, studies have been conventionally made on water absorption-quick drying, soft touch feeling, anti-transparency and the like using polyester materials, and spun yarns and woven or knitted fabrics using polyester fibers having a modified shape cross-section have been proposed.
For example, a spun yarn which is obtained by controlling the mixing ratio of 3 or 4 kinds of polyester-based short fibers having modified shape cross-sections to 15 to 20% by weight or more has been proposed (see Patent Document 1). However, in this proposal, there was a problem that water absorbability and soft touch feeling were not sufficient, because the spun yarn was composed of only synthetic fibers.
Further, a blended yarn which includes polyester short fibers having a modified shape cross-section having 3 or more projections in a cross-sectional shape thereof and a modified shape ratio of 1.8 or more, natural fibers and cellulose-based fibers has been proposed (see Patent Document 2). However, in this proposal, although the blended yarn including the polyester fibers having a modified shape cross-section, the natural fibers and the cellulose-based fibers were used, there was a problem that water absorbability and soft touch feeling were not sufficient yet.
Furthermore, a spun yarn in which soft touch feeling is obtained by using blended cotton yarn with polyester-based fibers having modified shape cross-section of multifoliar cross-section shape or polygonal shape and cellulose-based fibers, and anti-transparent properties are improved by further blending with high content of titanium fibers has been proposed (see Patent Document 3). However, also in this proposal, there was a problem that water absorbability and soft touch feeling were not always sufficient and that anti-transparent properties were also insufficient, as is the case with the proposal in Patent Document 2.

Prior Art Documents

Patent Documents

Patent Document 1: JP-A-9-59838
Patent Document 2: JP-A-2008-133584
Patent Document 3: JP-A-2012-188792

Summary of the Invention

Problems that the Invention is to Solve

An object of the present invention is therefore to provide a spun yarn having soft touch feeling which could not be realized by the above-mentioned conventional techniques in use of polyester-based fibers and further also having functions of high water absorbability, quick drying properties and anti-transparent properties which could not be realized only by natural fibers and cellulose-based fibers.
Further, another object of the present invention is to provide a woven or knitted fabric particularly suitable for clothing uses, for example, uses for inner shirts, pants, sports shirts, white coats, sweaters, national costumes and the like.

Means for Solving the Problems

The present inventors have focused on spaces among fibers. It has been presumed that water absorbability and soft touch feeling are not sufficient, because the spaces are less formed among the single fibers in the polyester fibers having a modified cross-section in Patent Document 2 of Prior-Art Documents. Further, it has been considered that the same applies in Patent Document 3 of Prior-Art Documents and further that irregular reflection of light caused by fiber surface shape is not sufficient also in anti-transparent properties. Furthermore, it has been presumed that not only unilaterally high water absorbability but also compatibility with quick drying properties is important.
Then, in order to solve the above-mentioned problems, the present inventors have found that soft touch feeling is realized by using polyester-based fibers having the specific flat multifoliar cross-section and cellulose-based fibers in combination, and that when processed into a spun yarn or a woven or knitted fabric, it has high water absorbability and quick drying properties and has high anti-transparent properties without blending with high content of titanium fibers, and then, the present invention has been accomplished.
That is, the spun yarn in the present invention includes 20 to 80% by mass of a polyester-based fiber having a flat multifoliar cross-section and 20 to 80% by mass of a cellulose-based fiber, wherein a cross-sectional shape of the polyester-based fiber having a flat multifoliar cross-section is a flat shape having 6 or more convex parts on a circumference thereof, and when a maximum length of a cross section of the polyester-based fiber having a flat multifoliar cross-section is taken as A, a maximum width of the cross-section of the polyester-based fiber having a flat multifoliar cross-section is taken as B, a length of a line connecting vertexes of convex parts which are adjacent to each other in a maximum concave-convex part is taken as C, and a length of a perpendicular line drawn from the line connecting the vertexes of the convex parts which are adjacent to each other in the maximum concave-convex part to a bottom point of a concave part is taken as D, a flat ratio defined by the following formula (1) and a modified shape ratio defined by the following formula (2) are satisfied. $Flat ratio (A / B) = 2.0 to 3.0$
$Modified shape ratio (C / D) = 1.0 to 5.0$
According to preferable aspects of the spun yarn of the present invention, the modified shape ratio is from 2.0 to 5.0.
According to preferable aspects of the spun yarn of the present invention, when the longest length except for the maximum width B of the cross-section among lines between vertexes of both convex parts opposing to each other using the maximum length A as an axis of symmetry is taken as E, a convex part ratio defined by the following formula (3) is satisfied. $Convex part ratio (E / B) = 0.6 to 0.9$
According to preferable aspects of the spun yarn of the present invention, a single filament fineness of the polyester-based fiber having a flat multifoliar cross-section is 2.0 dtex or less.
According to preferable aspects of the spun yarn of the present invention, the polyester-based fiber having a flat multifoliar cross-section contains an inorganic particle, and a content thereof is from 0.2 to 2.5 % by mass.
The above-mentioned spun yarn in the present invention can be suitably used for a woven or knitted fabric for clothing uses, for example, for inner shirts and sports shirts.

Advantageous Effects of the Invention

According to the present invention, it becomes possible to have spaces of variable size among fibers by having a flat shape and having concaves and convexes on an outer periphery portion thereof, and further by not equalizing the heights of the concaves and convexes on the outer periphery portion, and thus, a spun yarn having excellent water absorbability and quick drying properties and soft touch feeling, and a woven or knitted fabric using the same can be obtained. Further, according to the present invention, a spun yarn and woven or knitted fabric also having high anti-transparent performance are obtained.

Brief Description of the Drawings

[FIG. 1] FIG. 1 is a cross-sectional view for illustrating an example of a cross-sectional shape of a polyester-based fiber having a flat multifoliar cross-section included in the spun yarn in the present invention, which has a plurality (8) of convex parts on a circumference of a fiber cross section.

Mode for Currying Out the Invention

The spun yarn in the present invention will be described in detail below.
The spun yarn in the present invention is a spun yarn obtained by blending 20 to 80% by mass of polyester-based fibers having a flat multifoliar cross-section and 20 to 80% by mass of cellulose-based fibers.
The cellulose-based fibers used in the present invention are selected from at least one kind of cellulose-based fibers of natural fibers such as hemp, cotton and silk, regenerated fibers such as viscose rayon, cupra and solvent-spun cellulose, and semisynthetic fibers such as acetate. Of these, the regenerated fibers such as viscose rayon and solvent-spun cellulose are preferably used from the viewpoints of handleability, general versatility and functionality.
In the cellulose-based fibers used in the present invention, arbitrary cross-sectional shape is preferably a flat shape having concaves and convexes on a circumference thereof. Water absorbability is increased by having the concaves and convexes on the circumference, and further, liquid is uniformly diffused by a capillary action, so that there is an effect of having quick drying properties to easily keep dry feeling and refreshing cool feeling.
The number of the above-mentioned convex parts on the circumference is preferably from 6 to 14, and more preferably from 8 to 12. When the number of the convex parts present on the circumference of the cross-sectional shape is less than 6, spaces are decreased, thereby causing poor water absorbability, liquid retainability and diffusibility. Further, the irregular reflectance of light is decreased, thereby causing deteriorated anti-transparent properties. Furthermore, at the time of touching the skin, contact points decrease, thereby providing rough touch feeling. In addition, when the number of the convex parts exceeds 14, the cellulose-based fibers have low rigidity as compared to the polyester-based fibers and are easily worn away, resulting in a decrease in yarn strength. Further, liquid impregnated is held in the fibers because of their excessively high water absorbability, so that the liquid cannot be quickly evaporated, resulting in poor quick drying properties. Furthermore, the shape of the convex parts is preferably a rounded shape from the viewpoint of texture.
Further, the single filament fineness of the cellulose-based fibers is preferably from 1.0 to 5.0 dtex. The single filament fineness is more preferably from 1.2 to 2.2 dtex. When the single filament fineness is less than 1.0 dtex, the fibers tend to be easily wound around a cylinder of a card, thereby causing a significant reduction in process passability in some cases. As a result, a defect of the spun yarn tends to easily occur. Furthermore, when the single filament fineness exceeds 5.0 dtex, touch feeling at the time of touching human skin is hard, which shows an undesirable tendency in use in terms of soft touch feeling. In addition, the spaces among the fibers become excessively large by an increase in single filament fineness, so that water absorbability tends to be significantly deteriorated.
The fiber length of the cellulose-based fibers is preferably from 30 to 64 mm, from the viewpoints of high entanglement with other constituent fibers such as the polyester-based fibers to be blended and being able to improve card process passability. The fiber length is more preferably from 35 to 51 mm. Examples of commercially available products of the cellulose-based fibers include rayon (trade name "COLONA") manufactured by Daiwabo Rayon Co., Ltd., and the like.
In the spun yarn in the present invention, the content of the above-mentioned cellulose-based fibers is from 20 to 80% by mass. When the mixing ratio (content) of the cellulose-based fibers is less than 20% by mass, water absorbability for impregnating liquid becomes weak. Diffusibility is therefore deteriorated, and dry feeling and refreshing cool feeling of the spun yarn in the present invention are reduced. Further, in the spun yarn in the present invention, soft touch feeling peculiar to the cellulose-based fibers is also impaired, so that texture feeling during the use becomes inferior. Furthermore, when the mixing ratio of the cellulose-based fibers exceeds 80% by mass, water absorbability becomes excessively strong, and liquid impregnated is held in the fibers. Accordingly, the liquid cannot be quickly evaporated. That is, quick drying properties become poor.
A polyester constituting the polyester-based fibers used in the present invention means a high molecular weight polymer formed by a condensation reaction of terephthalic acid with ethylene glycol, trimethylene glycol, butylene glycol or the like, a condensate of sebacic acid, adipic acid, trimellitic acid, isophthalic acid, p-hydroxybenzoic acid or the like with polyethylene glycol or the like, a polyester polymer containing another polyester, and the like.
The polyester-based fibers having a flat multifoliar cross-section used in the present invention are polyester-based fibers in which the cross-sectional shape thereof is a flat shape having 6 or more convex parts. When the number of the convex parts present on a circumference of the cross-sectional shape is less than 6, spaces formed among fibers adjacent to one another are decreased, thereby causing poor water absorbability, liquid retainability and diffusibility. Further, the irregular reflectance of light is decreased, thereby causing deteriorated anti-transparent properties. When the number of the convex parts exceeds 12, the modified shape ratio tends to be extremely decreased from the feature of a production method of the polyester-based fibers, and the spaces formed among the fibers adjacent to one another are decreased, thereby causing poor water absorbability, liquid retainability and diffusibility, similarly as described above. The flat cross-sectional shape makes it possible to form spaces among fibers, which improves water absorbability, liquid retainability and diffusibility. Further, the irregular reflectance of light is increased, thereby improving anti-transparent properties. Furthermore, falling properties per single fiber are improved, so that soft touch feeling can be obtained.
FIG. 1 shows an example of a cross-sectional shape of a single fiber of the polyester-based fiber having a flat multifoliar cross-section used in the present invention. In FIG. 1, the cross-sectional shape of the polyester-based fiber having a flat multifoliar cross-section included in the spun yarn in the present invention, which has a plurality (8) of convex parts on the circumference of the fiber cross section is shown as an example.
In FIG. 1, A is the maximum length of the cross section of the above-mentioned polyester-based fiber having a flat multifoliar cross-section used in the present invention. B is the maximum width of the cross-section of the polyester-based fiber having a flat multifoliar cross-section, and means the length of a line of the maximum width connecting vertexes of convex parts vertically crossing the above-mentioned maximum length A. Further, C means the length of a line connecting vertexes of convex parts which are adjacent to each other in a maximum concave-convex part. Then, D means the length of a perpendicular line drawn from the line connecting the vertexes of the convex parts which are adjacent to each other in the maximum concave-convex part to a bottom point of a concave part. E means the longest length except for the maximum width B among lines between vertexes of both convex parts opposing to each other using the maximum length A as an axis of symmetry.
In the present invention, the polyester-based fibers in which the cross-sectional shape thereof is a flat shape having 6 or more convex parts are used. The number of convex parts is preferably 7 to 13 and more preferably 8 to 12. Further, the shape of the convex part is preferably a rounded shape from the viewpoint of texture.
In the polyester-based fibers having a flat multifoliar cross-section used in the present invention, it is important that the flat cross-sectional shape in the single fiber cross section satisfies the flat ratio defined by the following formula (1) and the modified shape ratio defined by the following formula (2). Further, in preferred embodiments, the convex part ratio defined by the following formula (3) is satisfied. $Flat ratio (A / B) = 2.0 to 3.0$
$Modified shape ratio (C / D) = 1.0 to 5.0$
$Convex part ratio (E / B) = 0.6 to 0.9$
In the spun yarn in the present invention, the flat ratio (A/B) is from 2.0 to 3.0. When the flat ratio (A/B) is less than 2.0, falling properties of fibers are deteriorated, thereby failing to obtain soft touch feeling. On the other hand, the flat ratio (A/B) exceeds 3.0, stiffness feeling is decreased, and permanent set in fatigue is liable to be caused. Further, fiber-forming properties are deteriorated, or the modified shape ratio is deteriorated. The flat ratio (A/B) is more preferably from 2.0 to 2.7, and still more preferably from 2.0 to 2.5.
Further, the modified shape ratio (C/D) represents the size of a concave part between the adjacent convex parts in the above-mentioned flat multifoliar shape. The larger value thereof indicates the smaller concave part, and the smaller value thereof indicates the larger concave part. When the modified shape ratio (C/D) is large, the concave part becomes shallow, and the spaces formed among the fibers are also decreased. Accordingly, water absorbability and diffusibility tend to be deteriorated. Furthermore, the irregular reflectance of light is also decreased, and anti-transparent properties tend to be deteriorated. Accordingly, the modified shape ratio (C/D) is 5.0 or less.
On the other hand, when the modified shape ratio (C/D) is excessively small, the concave part in the fiber cross section is easily bent, resulting in a failure to keep the flat shape. Further, the fibers are easily damaged by friction, so that there is a possibility that the skin might be hurt when rubbed therewith. From these facts, the modified shape ratio (C/D) is 1.0 or more. The modified shape ratio (C/D) is from 1.0 to 5.0 from the above viewpoint. Further, the modified shape ratio (C/D) is more preferably from 1.0 to 4.0 in terms of water absorbability and diffusibility, and still more preferably from 2.0 to 4.0 from the viewpoint of the balance between flat shape keeping properties, water absorbability and diffusibility.
Further, the convex part ratio (E/B) indicates the length ratio of the maximum width B and the longest length E except for the maximum width B of lines between vertexes of both convex parts using the maximum length A as an axis of symmetry in the above-mentioned flat multifoliar shape. This has a meaning as an index for measuring the degree of distortion of an approximately elliptic shape obtained when lines connecting vertexes of the respective convex parts of the maximum width B, E and the maximum length A are drawn. When the convex part ratio is excessively small, the depth of the concave part is decreased, and the cross-sectional shape thereof becomes a shape closely approximate to a flat cross shape. For this reason, a capillary phenomenon effect is decreased, and water absorbability and diffusibility are deteriorated. Further, at the time of touching the skin, the number of touching convex parts decreases, because of the shape approximate to the flat cross shape, and texture feeling and softness are deteriorated. Accordingly, the convex part ratio is preferably 0.6 or more. On the other hand, when the convex part ratio is excessively large, many concave parts are completely blocked in the case where the concaves and convexes of the fibers are fitted to each other. The spaces are therefore decreased, and water absorbability and diffusibility are deteriorated. Further, at the time of touching the skin, the number of touching convex parts decreases, because of the shape approximate to the flat hexagonal shape, and texture feeling and softness are deteriorated. From these facts, the convex part ratio (E/B) is preferably 0.9 or less. The convex part ratio (E/B) is preferably from 0.6 to 0.9 from the above-mentioned viewpoint. Further, from the viewpoint of a balance thereof, the convex part ratio (E/B) is preferably from 0.6 to 0.8, and more preferably from 0.7 to 0.8.
The content of the polyester-based fibers having a flat multifoliar cross-section in the spun yarn used in the present invention is from 20 to 80% by mass. When the mixing rate (content) of the polyester-based fibers having a flat multifoliar cross-section is less than 20% by mass, hydrophobicity of the spun yarn is decreased. Accordingly, water absorbed tends to become difficult to be evaporated, quick drying properties are poor, and texture feeling is also deteriorated. Further, when the mixing ratio (content) of the polyester-based fibers having a flat multifoliar cross-section exceeds 80% by mass, the capillary phenomenon effect becomes weak and liquid diffusibility is deteriorated, thereby impairing dry feeling and refreshing cool feeling at the time of touching the skin. From the above, as a preferred balance, the content of the polyester-based fibers having a flat multifoliar cross-section in the spun yarn is from 30 to 70% by mass, and more preferably from 40 to 60% by mass.
The single filament fineness of the polyester-based fibers having a flat multifoliar cross-section used in the present invention is preferably 2.0 dtex or less. The single filament fineness is more preferably from 1.0 to 2.0 dtex, and still more preferably from 1.2 to 1.8 dtex. When the single filament fineness exceeds 2.0 dtex, rigidity peculiar to the polyester-based fiber is increased, so that irritation of texture feeling becomes strong, and soft touch feeling is also impaired in some cases. Further, the spaces formed among the fibers are excessively increased, so that the capillary phenomenon effect becomes weak and liquid diffusibility is deteriorated, thereby tending to impair dry feeling and refreshing cool feeling at the time of touching the skin. Furthermore, when the single filament fineness is less than 1.0 dtex, process passability in a carding process is deteriorated, and the productivity tends to be reduced.
The polyester-based fibers having a flat multifoliar cross-section used in the present invention can be allowed to contain inorganic particles, for the purpose of improving anti-transparent properties and softness
The content of the inorganic particles is preferably from 0.2 to 2.5% by mass, more preferably from 0.2 to 2.2% by mass, and still more preferably from 0.3 to 2.0% by mass. When the content of the inorganic particles is less than 0.2% by mass, friction with the cellulose-based fibers is increased, and the soft touch feeling tends to be impaired, and further, the irregular reflection of light becomes insufficient, and the anti-transparent performance tends to be deteriorated. On the other hand, when the content of the inorganic particles exceeds 2.5% by mass, process passability in spinning is deteriorated, and the guide wear tends to occur, and further, the modified shape ratio of the polyester-based fibers having a flat multifoliar cross-section tends to be decreased during melt spinning thereof. Furthermore, a matte effect acts strongly, so that whiteness is inferior, and color developability tends to be lost.
Further, the fiber length of the polyester-based fibers having a flat multifoliar cross-section is preferably from 30 to 64 mm, and more preferably from 35 to 51 mm, from the viewpoint of process passability in spinning.
The spun yarn in the present invention and a production method thereof will be described below.
The twist coefficient of the spun yarn in the present invention is preferably within a range of 3.0 to 4.5. When the twist coefficient is less than 3.0, sufficient yarn strength tends to be not obtained, and yarn breakage during spinning or a reduction in strength when it is formed into the woven or knitted fabric tends to be brought about. Further, when the twist coefficient exceeds 4.5, a kink caused by untwisting tends to occur, and when it is formed into the woven or knitted fabric, it tends to have coarse feeling.
The spun yarn in the present invention can be produced by an ordinary spinning method using the polyester-based fibers having a flat multifoliar cross-section and the cellulose-based fibers, and can be produced using a ring spinning frame (including bundling and eddy-current types), an air spinning frame or the like.
Further, with regard to a blending method, it is possible to blend two kinds of the polyester-based fibers having a flat multifoliar cross-section and the cellulose-based fibers, and also possible to blend with other fibers within the blending ratio range in the present invention. In the case of being used particularly for inner materials or shirt materials, the count of the spun yarn is preferably from 30 to 53, and more preferably 40.
The woven or knitted fabric including the spun yarn in the present invention may be a woven or knitted fabric using 100% of the spun yarn in the present invention. However, in preferred embodiments, at least 40% by mass of the spun yarn in the present invention is contained. When the ratio of the spun yarn in the present invention is less than 40% by mass, there is a tendency that the water absorbability effect due to the combination of the polyester-based fibers having a flat multifoliar cross-section and the cellulose-based fibers according to the present invention is less likely to be obtained. Further, in the woven or knitted fabric in the present invention, it is possible to use the spun yarn in the present invention within a range of less than 60% by mass, and to mixedly weave or knit other spun yarn, filaments or the like, in addition to the spun yarn in the present invention.
The spun yarn in the present invention and the woven or knitted fabric using the same have water absorbability, quick drying properties and anti-transparent properties and soft touch feeling, so that they can be suitably used as inner shirts, pants, sports shirts, white coats, sweaters, national costumes and the like.

Examples

The spun yarn in the present invention will be described in detail below with reference to examples. However, the present invention should not be construed as being limited to only the examples. Respective physical property values in the examples were measured by the following methods.

Evaluation was performed in accordance with JIS L1907 (2010 edition, Byreck method). Evaluation contents were as follows. In the present invention, "⊙" and "○" were judged as passed.

⊙: 80 mm or more
○: 70 to 79 mm
Δ: 50 to 69 mm
x: 49 mm or less

A test specimen allowed to stand for 24 hours under an atmosphere of a room temperature of 25°C and a humidity of 40% RH is cut out into a 10-cm square, and the mass (A) thereof is measured. The test specimen is immersed in ion-exchanged water for 30 seconds, and thereafter taken out of the liquid by pinching one corner of the test specimen with tweezers. The test specimen taken out is allowed to stand for 1 hour similarly under an atmosphere of a room temperature of 25°C and a humidity of 40% RH, followed by naturally drying, and the mass (B) thereof is measured. The residual water content (C) is calculated by the following formula: $C (%) = (B - A) / A \times 100$
Evaluation contents were as follows. In the present invention, "⊙" and "○" were judged as passed.

⊙: 30% or less
○: 31 to 40%
Δ: 41 to 50%
x: 51% or more

<Anti-Transparent Property>

Using a spectrophotometer (Minolta M-3600d), respective L values (reflectances) were measured using a standard white board and a standard black board as backgrounds of a sample cloth, and the anti-transparent degree (%) was determined by the following formula: $Anti - transparent degree (%) = 100 - (Lfw - Lfb) / (Lw - Lb) \times 100$

Lw: L value of the standard white board in a state where there was no sample cloth
Lb: L value of the standard black board in a state where there was no sample cloth
Lfw: L value when the sample cloth was placed on the standard white board
Lfb: L value at the time when the sample cloth was placed on the standard black board

Evaluation contents were as follows. In the present invention, "⊙" and "○" were judged as passed.

⊙: 70% or more
○: 60 to 69%
Δ: 50 to 59%
x: 49% or less

A test specimen was cut out into a 10-cm square, and the test specimen cut out was grasped by five subjects, and point evaluation was performed according to the following criteria. Thereafter, the average points were calculated, and in the present invention, "⊙" and "○" were judged as passed.

3 points: Touch feeling was soft.
2 points: Touch feeling was somewhat hard.
1 point: Touch feeling was hard.
⊙: 2.8 points or more
○: 2.4 to 2.7 points
Δ: 1.9 to 2.3 points
x: 1.8 points or less

[Example 1]

20% by mass of polyester-based fibers having a flat multifoliar cross-section (fiber length: 51 mm) having a single filament fineness of 1.7 dtex, a titanium oxide content of 0.3% by mass, a flat ratio of 2.1, a modified shape ratio of 2.7 and a convex part ratio of 0.8 and having a cross-sectional shape with 8 convex parts and 80% by mass of rayon fibers (fiber length: 51 mm) having a single filament fineness of 1.7 dtex were blended to obtain a spun yarn having an English cotton count of 40 s, setting the twist coefficient K to 3.5. Using the spun yarn as warps and wefts, a plain woven fabric having a warp density of 110 ends/2.54 cm and a weft density of 76 picks/2.54 cm was obtained using an air jet loom. The fiber constitution of the spun yarn is shown in Table 1, and the evaluation results are shown in Table 2.

[Example 2]

50% by mass of polyester-based fibers having a flat multifoliar cross-section (fiber length: 51 mm) having a single filament fineness of 1.7 dtex, a titanium oxide content of 0.3% by mass, a flat ratio of 2.1, a modified shape ratio of 2.7 and a convex part ratio of 0.8 and having a cross-sectional shape with 8 convex parts and 50% by mass of rayon fibers (fiber length: 51 mm) having a single filament fineness of 1.7 dtex were blended to obtain a spun yarn having an English cotton count of 40 s, setting the twist coefficient K to 3.5. Using the spun yarn as warps and wefts, a plain woven fabric having a warp density of 110 ends/2.54 cm and a weft density of 76 picks/2.54 cm was obtained using an air jet loom. The fiber constitution of the spun yarn is shown in Table 1, and the evaluation results are shown in Table 2.

[Example 3]

80% by mass of polyester-based fibers having a flat multifoliar cross-section (fiber length: 51 mm) having a single filament fineness of 1.7 dtex, a titanium oxide content of 0.3% by mass, a flat ratio of 2.1, a modified shape ratio of 2.7 and a convex part ratio of 0.8 and having a cross-sectional shape with 8 convex parts and 20% by mass of rayon fibers (fiber length: 51 mm) having a single filament fineness of 1.7 dtex were blended to obtain a spun yarn having an English cotton count of 40 s, setting the twist coefficient K to 3.5. Using the spun yarn as warps and wefts, a plain woven fabric having a warp density of 110 ends/2.54 cm and a weft density of 76 picks/2.54 cm was obtained using an air jet loom. The fiber constitution of the spun yarn is shown in Table 1, and the evaluation results are shown in Table 2.

[Example 4]

80% by mass of polyester-based fibers having a flat multifoliar cross-section (fiber length: 51 mm) having a single filament fineness of 1.7 dtex, a titanium oxide content of 0.1% by mass, a flat ratio of 2.0, a modified shape ratio of 2.5 and a convex part ratio of 0.7 and having a cross-sectional shape with 8 convex parts and 20% by mass of rayon fibers (fiber length: 51 mm) having a single filament fineness of 1.7 dtex were blended to obtain spun yarn having an English cotton count of 40 s, setting the twist coefficient K to 3.5. Using the spun yarn as warps and wefts, a plain woven fabric having a warp density of 110 ends/2.54 cm and a weft density of 76 picks/2.54 cm was obtained using an air jet loom. The fiber constitution of the spun yarn is shown in Table 1, and the evaluation results are shown in Table 2.

[Comparative Example 1]

85% by mass of polyester-based fibers having a flat multifoliar cross-section (fiber length: 51 mm) having a single filament fineness of 1.7 dtex, a titanium oxide content of 0.3% by mass, a flat ratio of 2.1, a modified shape ratio of 2.7 and a convex part ratio of 0.8 and having a cross-sectional shape with 8 convex parts and 15% by mass of rayon fibers (fiber length: 51 mm) having a single filament fineness of 1.7 dtex were blended to obtain a spun yarn having an English cotton count of 40 s, setting the twist coefficient K to 3.5. Using the spun yarn as warps and wefts, a plain woven fabric having a warp density of 110 ends/2.54 cm and a weft density of 76 picks/2.54 cm was obtained using an air jet loom. The fiber constitution of the spun yarn is shown in Table 1, and the evaluation results are shown in Table 2.

[Comparative Example 2]

15% by mass of polyester-based fibers having a flat multifoliar cross-section (fiber length: 51 mm) having a single filament fineness of 1.7 dtex, a titanium oxide content of 0.3% by mass, a flat ratio of 2.1, a modified shape ratio of 2.7 and a convex part ratio of 0.8 and having a cross-sectional shape with 8 convex parts and 85% by mass of rayon fibers (fiber length: 51 mm) having a single filament fineness of 1.7 dtex were blended to obtain a spun yarn having an English cotton count of 40 s, setting the twist coefficient K to 3.5. Using the spun yarn as warps and wefts, a plain woven fabric having a warp density of 110 ends/2.54 cm and a weft density of 76 picks/2.54 cm was obtained using an air jet loom. The fiber constitution of the spun yarn is shown in Table 1, and the evaluation results are shown in Table 2.

[Comparative Example 3]

80% by mass of polyester-based fibers having a trifoliar (Y-shaped) cross-section (fiber length: 51 mm) having a single filament fineness of 1.7 dtex, a titanium oxide content of 0.3% by mass, a flat ratio of 1.0, a modified shape ratio of 6.7 and a convex part ratio of 0.9 and having a cross-sectional shape with 3 convex parts and 20% by mass of rayon fibers (fiber length: 51 mm) having a single filament fineness of 1.7 dtex were blended to obtain a spun yarn having an English cotton count of 40 s, setting the twist coefficient K to 3.5. Using the spun yarn as warps and wefts, a plain woven fabric having a warp density of 110 ends/2.54 cm and a weft density of 76 picks/2.54 cm was obtained using an air jet loom. The fiber constitution of the spun yarn is shown in Table 1, and the evaluation results are shown in Table 2.

[Comparative Example 4]

80% by mass of polyester-based fibers (fiber length: 51 mm) having a rounded cross-sectional shape having a single filament fineness of 1.7 dtex and a titanium oxide content of 0.3% by mass and 20% by mass of rayon fibers (fiber length: 51 mm) having a single filament fineness of 1.7 dtex were blended to obtain a spun yarn having an English cotton count of 40 s, setting the twist coefficient K to 3.5. Using the spun yarn as warps and wefts, a plain woven fabric having a warp density of 110 ends/2.54 cm and a weft density of 76 picks/2.54 cm was obtained using an air jet loom. The fiber constitution of the spun yarn is shown in Table 1, and the evaluation results are shown in Table 2.

[Table 1]

Fibers Used	Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative Example 2	Comparative Example 3	Comparative Example 4
Polyester having octafoliar flat cross-section (mass%)	20	50	80	80	85	15
Polyester having trifoliar (Y) cross-section (mass%)							80
Polyester having rounded cross-section (mass%)								80
Rayon (mass%)	80	50	20	20	15	85	20	20
Titanium oxide content (mass%)	0.3	0.3	0.3	0.1	0.3	0.3	0.3	0.3

[Table 2]

	Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative Example 2	Comparative Example 3	Comparative Example 4
Water Absorbability	⊙	⊙	⊙	⊙	○	○	Δ	×
Quick Drying Property	⊙	⊙	⊙	⊙	⊙	×	○	Δ
Anti-Transparent Property	⊙	⊙	⊙	○	⊙	Δ	Δ	×
Soft Touch Feeling	⊙	⊙	⊙	○	Δ	⊙	×	×

Description of Reference Numerals and Signs

A: The maximum length of a cross section of a polyester-based fiber having a flat multifoliar cross-section
B: The maximum width of the cross-section of the polyester-based fiber having a flat multifoliar cross-section
C: The length of a line connecting vertexes of convex parts which are adjacent to each other in a maximum concave-convex part
D: The length of a perpendicular line drawn down from the line connecting the vertexes of the convex parts which are adjacent to each other in the maximum concave-convex part to a bottom point of a concave part
E: The longest length except for the maximum width B among lines between vertexes of both convex parts opposing to each other using the maximum length A as an axis of symmetry

Claims

A spun yarn comprising 20 to 80% by mass of a polyester-based fiber having a flat multifoliar cross-section and 20 to 80% by mass of a cellulose-based fiber, wherein a cross-sectional shape of the polyester-based fiber having a flat multifoliar cross-section is a flat shape having 6 or more convex parts on a circumference thereof, and when a maximum length of a cross section of the polyester-based fiber having a flat multifoliar cross-section is taken as A, a maximum width of the cross-section of the polyester-based fiber having a flat multifoliar cross-section is taken as B, a length of a line connecting vertexes of convex parts which are adjacent to each other in a maximum concave-convex part is taken as C, and a length of a perpendicular line drawn from the line connecting the vertexes of the convex parts which are adjacent to each other in the maximum concave-convex part to a bottom point of a concave part is taken as D, a flat ratio defined by the following formula (1) and a modified shape ratio defined by the following formula (2) are satisfied. $Flat ratio (A / B) = 2.0 to 3.0$
$Modified shape ratio (C / D) = 1.0 to 5.0$
The spun yarn according to claim 1, wherein the modified shape ratio is from 2.0 to 5.0.
The spun yarn according to claim 1 or 2, wherein when the longest length except for the maximum width B of the cross-section among lines between vertexes of both convex parts opposing to each other using the maximum length A as an axis of symmetry is taken as E, a convex part ratio defined by the following formula (3) is satisfied. $Convex part ratio (E / B) = 0.6 to 0.9$
The spun yarn according to any one of claims 1 to 3, wherein a single filament fineness of the polyester-based fiber having a flat multifoliar cross-section is 2.0 dtex or less.
The spun yarn according to any one of claims 1 to 4, wherein the polyester-based fiber having a flat multifoliar cross-section contains an inorganic particle, and a content thereof is from 0.2 to 2.5 % by mass.
A woven or knitted fabric comprising the spun yarn according to any one of claims 1 to 5.