CN114729477A

CN114729477A - Fabric for swimwear and swimwear using same

Info

Publication number: CN114729477A
Application number: CN202080079126.6A
Authority: CN
Inventors: 春田胜; 木村知佳; 鸟谷部慧悟
Original assignee: Toray Industries Inc
Current assignee: Toray Industries Inc
Priority date: 2019-11-21
Filing date: 2020-11-19
Publication date: 2022-07-08
Anticipated expiration: 2040-11-19
Also published as: WO2021100810A1; US20220403566A1; CN114729477B; EP4063546A1; JPWO2021100810A1; EP4063546A4

Abstract

The present invention provides a swimsuit which satisfies tensile properties, strength, mobility and the like as a swimsuit, has excellent hydrophobicity, and reduces frictional resistance between the surface of the swimsuit and water. The fabric for swimwear of the present invention is a woven structure in which a core-spun covered yarn comprising an elastic fiber as a core yarn and a synthetic fiber filament as a sheath yarn is disposed in at least a part of warp and weft yarns and has a large number of floats in a fabric structure diagram, wherein the direction having the large number of floats is the body length (height) direction of the swimwear, and the ratio of the resistance yarn in the direction perpendicular to the body length (height) direction is 40% or less, and is suitably used for swimwear.

Description

Fabric for swimsuit and swimsuit using same

Technical Field

The present invention relates to a fabric for swimwear and swimwear comprising the same.

Background

In a swimming competition for competing for speed, improvement of swimming skill and physical strength of players is the most important factor in order to further break the speed record, but reduction of water resistance of swimming suits for the swimming competition is also an important subject. Therefore, improvement of smoothness and seams of the surface of the swimwear garment has been conventionally performed.

In order to reduce the frictional resistance with water, there has been proposed a swimsuit utilizing a turbulent drag reduction effect (Toms effect) in which an aqueous solution of a high-molecular-weight linear organic polymer is applied to the fiber surface of the swimsuit and the polymer is dissolved in water to reduce the frictional resistance (patent document 1). While it does reduce water frictional resistance, it is pointed out that dissolved polymer can contaminate the pool water.

In addition, the following solutions are proposed: by smoothing the surface of the fabric and providing a hydrophobic portion and a non-hydrophobic portion, water is less likely to enter the inside of the swimsuit and water that has entered the swimsuit is easily drained, thereby reducing water resistance (patent document 2). However, since the arrangement ratio of the hydrophobic portion to the non-hydrophobic portion and the shape after wearing vary from person to person, sufficient effects cannot be exerted unless the garment is manufactured in a single mode suitable for each person, and a counter effect is produced.

In addition, the following textile swimwear is proposed: the surface of a woven fabric obtained by using a covering yarn using a spandex fiber as a core yarn and a synthetic fiber as a sheath yarn as a warp yarn and a weft yarn is smoothed and subjected to a hydrophobic treatment, and the fabric has both of a sportswear-following property and a compression function by an appropriate stress (patent document 3). However, it is difficult to achieve both smoothness and stretchability, and either smoothness or stretchability is often sacrificed. When the smoothness is improved by performing rolling or the like in consideration of the water friction resistance, the stretchability of the yarn and the sliding between the yarns for weaving become poor, and the stretchability is lowered. If the stretchability is reduced, the swimwear is not easily moved unless the shape of the swimwear is individually matched to the shape of the wearer's body, and the mobility is hindered.

Further, there has been proposed a method of subjecting a swimsuit to a hydrophobic process to cause the swimmer's breath to be discharged into water, thereby forming a thin air flow on the cloth surface, and reducing water frictional resistance by the air film and air bubbles (patent document 4); there has been also made a new attempt to reduce water friction resistance by making a concave portion on the back surface (skin side) of a water-repellent swimwear by a weave or an embossing process and covering the surface of the swimwear with air bubbles by allowing air to flow out from the concave portion in water (patent document 5).

These water friction resistance reduction techniques using air films and air bubbles have been previously carried out in the development of techniques for ships, but have not yet reached a level applicable to practical use as swimwear. In the technique described in patent document 4, it is necessary to adjust the position of the air discharged in the water, the body orientation, and the like so as to catch the breath of the swimmer on the swimsuit surface, and this is certainly difficult to do during a violent competition. In addition, in the technique described in patent document 5, in order to store air, the area and volume of the concave portion need to be increased, and the thickness of the woven fabric inevitably becomes thick, so that the water friction resistance may be increased, and the mobility of the body may be hindered.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 1-213403

Patent document 2: japanese laid-open patent publication No. 8-311751

Patent document 3: japanese patent laid-open publication No. 2011-256483

Patent document 4: japanese laid-open patent publication No. 8-41708

Patent document 5: international publication No. 2012/073648

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made to solve the above conventional problems, and an object of the present invention is to provide a fabric for a swimsuit and a swimsuit comprising the same, which satisfy tensile properties, strength, mobility and the like of the swimsuit and reduce water resistance on the fabric surface of the swimsuit during rapid swimming such as a swimming match.

Means for solving the problems

The present invention has the following configuration to solve the above problems.

(1) A fabric for swimwear, which is an elastic fabric comprising a core-spun covered yarn comprising an elastic fiber as a core yarn and a synthetic fiber filament as a sheath yarn disposed at least in part of a warp yarn and a weft yarn, wherein the fabric has a woven structure with a large number of floats in either the warp yarn or the weft yarn on the surface thereof, the direction with the large number of floats is defined as the body length (height) direction of the swimwear, and the percentage of the resistance yarn in the direction perpendicular to the body length (height) direction, which is represented by the following formula (I), is 40% or less.

Rr＝(F/P)×100···(I)

Rr: percent resistance yarn ratio (%)

F: number (number) of squares of floating grain in a direction perpendicular to the length (height) direction of the swimsuit in one complete organization (weave repeat)

P: number of blocks of a complete organization

(2) The fabric for swimwear according to item (1) above, which is the stretch fabric, has a total coating coefficient represented by formula (II) below of 2800 or more, and has a coating coefficient in a direction with many floats of warp or weft and a coating coefficient in a direction with few floats on the fabric surface satisfying formula (III) below.

cf＝〔√Dx×My〕+〔√Dy×My〕···(II)

cfx≥cfy···(III)

cf: total coating coefficient

cfx ═ Dx × My ]: coating coefficient of multiple directions of floating grains

cfy [ √ Dy × My ]: coating coefficient in direction with less emboss

And Dx: fineness (dtex) of weaving yarn in multi-direction of raised grain

Dy: fineness (dtex) of weaving yarn in direction with less floating grain

Mx: fabric density in multiple directions of embossments (root/2.54 cm)

My: fabric density in the direction of little float (root/2.54 cm)

(3) The fabric for swimwear according to (1) or (2) above, wherein the core-spun coated yarn is disposed in at least one of the warp and the weft, which has a large number of embossments on the fabric surface.

(4) The fabric for swimwear according to any one of the above (1) to (3), wherein the synthetic fiber filament is a synthetic fiber filament having a plurality of furrows in a surface in a longitudinal direction of the fiber.

(5) The fabric for swimwear according to item (4) above, wherein the synthetic fiber filaments have a groove depth of 1.0 to 10.0 μm, a groove entrance width of 1.0 to 10.0 μm, and a protrusion width of 10.0 μm or less.

(6) The fabric for swimwear according to (4) or (5), wherein the synthetic fiber filaments have a cross-sectional shape in which the groove portions have a wide width and satisfy the following formulae (IV) and (V).

(SWmax)/(SWmin)≥1.3····(IV)

0.15≤(SH/D)≤0.25····(V)

(SWmin): width of entrance of groove (mum)

(SWmax): width (mum) of wide part of groove

D: diameter of fiber (μm)

SH: depth of groove (μm)

(7) The fabric for swimwear according to any one of (1) to (6) above, wherein the synthetic fiber filaments are polyamide fibers.

(8) The swimsuit fabric according to any one of (1) to (7) above, which is an elastic fabric having a woven structure at least a part of which is an 1/2 twill weave.

(9) The swimsuit fabric according to any one of (1) to (8) above, which is an elasticized fabric having a woven structure at least a part of which is a quintesunate structure.

(10) The fabric for swimwear according to any one of (1) to (9) above, which is subjected to a hydrophobic treatment.

(11) A swimsuit comprising the swimsuit fabric according to any one of (1) to (10) above, wherein a direction in which many floating streaks are present is a length (height) direction of the swimsuit.

(12) The swimsuit according to the above (11), wherein the swimsuit is used for a swimming match.

Effects of the invention

The present invention can solve the above conventional problems and provide swimwear that has excellent hydrophobicity and that satisfies the requirements of swimwear such as tensile properties, strength, and mobility, and that has reduced water resistance (resistance between the fabric surface and water) to which the fabric surface of the swimwear is subjected.

Drawings

FIG. 1: FIG. 1 is a repeating pattern of the surface of an 1/2 twill weave.

FIG. 2: FIG. 2 is a repeating pattern of the back side of an 1/2 twill weave.

FIG. 3: FIG. 3 is a repeating pattern of 2/1 twill textured surfaces.

FIG. 4: FIG. 4 is a full weave diagram of a plain weave fabric.

FIG. 5: fig. 5 is a perfect weave diagram of a surface of a quinquephyll satin weave.

FIG. 6: fig. 6 is a schematic diagram showing an appearance of the return water tank.

FIG. 7 is a schematic view of: fig. 7 is a side view of an apparatus for explaining the measurement of water frictional resistance using a smooth sample plate in a return water tank.

FIG. 8: fig. 8 is a schematic diagram for explaining a method of sewing a sample mounted on a smooth sample plate.

FIG. 9: fig. 9 is a side cross-sectional view of an apparatus for explaining measurement of a peel angle of a boundary layer of flowing water using a cylindrical sample mount in a return water tank.

FIG. 10: fig. 10 is a schematic diagram for explaining a method of sewing a sample mounted on a column sample mounting table.

FIG. 11: fig. 11 a is a schematic cross-sectional view showing an example of the cross-sectional shape of a single fiber of a star-shaped cross-section yarn (V-groove) constituting the synthetic fiber multifilament yarn used for the swimsuit fabric of the present invention. Fig. 11 b is a schematic cross-sectional view showing an example of the cross-sectional shape of a single fiber having narrow grooves, which is also a round-section yarn. Fig. 11 c and 11d are enlarged views of the narrow groove portion of fig. 11 b.

FIG. 12: fig. 12 is a photograph showing an example of evaluation of the peel angle of the boundary layer of water, and a of fig. 12 is a photograph obtained by setting and photographing a woven fabric for measuring the peel angle according to the measurement method for measuring the peel angle of the boundary layer of flowing water in the (10) cylindrical sample mount described in the example. Here, the lighting of the room is not turned off and the laser is not irradiated. Fig. 12 b is a photograph taken by closing the illumination of the room in the same state and irradiating the room with laser light after being placed in a dark room (the angle of separation of the boundary layer is measured using the photograph).

Detailed Description

The present invention will be described in detail below.

The fabric for swimwear of the present invention is a fabric for swimwear in which a covering-covered yarn comprising a synthetic fiber filament such as a polyester filament, a polyamide filament, a polypropylene filament, or a polyethylene filament as a sheath yarn and an elastic fiber such as a polyurethane spandex, a polyether ester elastic fiber, or a polybutylene terephthalate fiber or a polytrimethylene terephthalate fiber as a core yarn is disposed at least in a part of a warp or a weft.

Among the elastic fibers, particularly, a covering yarn using polyurethane spandex as a core yarn and synthetic fiber filaments as a sheath yarn is preferable because it is excellent in elongation and recovery from elongation and also has strength required for swimwear, particularly swimwear for rapid swimming.

The method for producing the covering yarn using the spandex such as spandex as the core and the synthetic fiber filament as the sheath is not particularly limited, but the covering property of the covering yarn using the covering machine is excellent, and it is preferable that the color difference and the gloss unevenness are less likely to occur when the covering yarn is formed into a woven fabric.

The method of covering may be either single-core covering in which the core yarn is covered with unidirectional twist or double-core covering in which 2 sheath yarns are covered with the core yarn in the S direction and the Z direction. In addition, in the case of covering, the stretch ratio is set to 3 times or more, more preferably 3.5 times or more, and as an upper limit, preferably 4 times or less, in order to have high tensile properties by applying a moderate draft to the elastic fiber such as spandex. If the draft ratio is too low, high tensile properties cannot be obtained, whereas if it is too high, yarn breakage occurs in the production stage of the core-spun coated yarn, and the yield decreases.

In the bidirectional elastic fabric using elastic fiber for both warp and weft, thread hooking is easy to become a problem when the fabric is used for swimwear. Therefore, the twist factor of the core-covered yarn is preferably 4500 to 15000, more preferably 7500 to 12000.

The twist factor is calculated by the following equation.

Twist factor ═ SS ÷ D + SC)^1/2×R

And SS: denier of spandex (dtex)

And (3) SC: fineness of sheath yarn (dtex)

D: draft ratio of spandex (times)

R: number of covers (T/m)

The elastic fiber of the core yarn is preferably 33dtex or more. When only the exercise following ability is required, it is sufficient to achieve excellent stretch recovery with a small force, and therefore, from the viewpoint of weight reduction, 22dtex or less is not a problem, and when the swimwear is used for a swimwear requiring a wearing pressure and preventing looseness, 33dtex or more and 156dtex or less are preferable. If the fineness is too large, the weight per unit area becomes too large.

Further, as commercially available spandex suitable for swimwear, particularly for swimwear used for rapid swimming such as a swimming race, there are preferably mentioned "ROICA SP", Toray Opelontex co., ltd. "LYCRA-176B" and "LYCRA-254B", which are available from asahi chemical fiber corporation, which are excellent in chlorine resistance.

As the synthetic fiber filament used for the sheath yarn, a filament obtained by melt spinning a polyester filament, a polyamide filament, a polypropylene filament, a polyethylene filament, or the like can be used.

The fineness is preferably 11dtex or more, and more preferably 16dtex or more, because the finer fineness is more preferable from the viewpoint of light weight, but if the fineness is too small, the strength is too low, and a problem of see-through also occurs. Further, since the weight per unit area becomes heavy when the thickness is too large, it is preferably 156dtex or less, and more preferably 110dtex or less. From the viewpoint of productivity, the filament fineness of the synthetic fiber filaments is preferably 2dtex to 6 dtex. More preferably 3dtex to 5 dtex. When the thickness is smaller than 2dtex, the cross-sectional shape tends to be too precise and complicated, and the production stability tends to be insufficient. When the thickness is larger than 6dtex, the hand becomes rough and hard.

The cross-sectional shape of the synthetic fiber filament may be any shape such as a circle, a triangle, a quadrilateral, an ellipse, or a hollow shape, depending on the purpose. In addition, a matte agent such as titanium oxide can be optionally added. For use in swimwear, a semi-dull yarn or a full-dull yarn having a small see-through feeling is preferably used. Further, any yarn processing such as false twisting using a single stage heater, or blending using a two stage heater (Japanese: ブレリア) may be performed. From the viewpoint of imparting stretchability, it is preferable to use a false twist yarn.

In the case of swimwear applications in which the blend ratio of the elastic fiber is 15% or more and the blend ratio is high, there is a concern that sublimation of a disperse dye or color fastness reduction due to staining may occur as the elastic fiber such as spandex including polyurethane, and polyamide filaments using an acid dye can be preferably used as the sheath yarn as compared with polyester filaments mainly dyed with a disperse dye. Polypropylene filaments and polyethylene filaments have a problem of being undyed, and a dope dyed yarn basically made of a pigment is accompanied by inconvenience. In addition, the problem of fastness can also be improved using polyesters dyeable with cationic dyes.

In addition, in the present invention, the weave is important. The weave structure is required to be a woven structure having a large number of embossments in either the warp or the weft, and the ratio of the resistant yarn in the direction perpendicular to the direction having a large number of embossments (resistant yarn ratio) is required to be at least 40% or less, more preferably 35% or less. The resistance yarn ratio is expressed by the following formula.

Rr＝(F/P)×100

Rr: percent resistance yarn (%)

F: number of blocks of floating grain in a direction perpendicular to the length direction of a completely organized swimsuit

P: number of blocks of a complete organization

In view of the frictional resistance between the surface of the swimsuit and water during a swimming match, the woven yarn used for the fabric of the swimsuit has a small water frictional resistance in the lengthwise direction parallel to the swimming travel direction, and the higher the ratio of the resistant yarn arranged in the direction perpendicular to the travel direction, the larger the water frictional resistance.

In the case of a plain weave fabric used for conventional swimming suit swimsuits, the percentage of the resistant yarn is 50%, and the yarn arranged parallel to the direction of travel of swimming and the yarn arranged perpendicular to the direction of travel are each half. When the percentage of the resistant yarn is higher than 50% by the woven structure, the water friction resistance between the surface of the fabric and water becomes large, which affects the speed of the swimming match and deteriorates the record. If the warp and weft are interlaced and the form of the woven fabric is maintained, the smaller the ratio of the resistant yarn is, the more preferable it is, but if the ratio is too small, the interlacing points between the warp and weft become small, and mesh twisting of the weaving yarn occurs. Further, the crimp ratio of the weaving yarn becomes unstable and the water friction resistance may become large, and the resistance yarn ratio is preferably in the range of 40 to 10%, and more preferably in the range of 35 to 15%.

In the core yarn obtained by using the covering machine, the synthetic fiber filament of the sheath yarn is wound around the core yarn at a twist angle inclined with respect to the direction of the weaving yarn, due to the influence of the number of twisted yarn twists. Therefore, when the sheath yarn is observed alone, the sheath yarn is not precisely parallel to the running direction due to the influence of the twist angle, but the water friction resistance is low as long as the core yarn as the entire weaving yarn can be used so as to be parallel to the running direction.

The method of calculating the ratio of the resistance yarn will be described in more detail with reference to a perfect weave diagram of an 1/2 twill weave shown in fig. 1. A perfect weave means the smallest unit of a weave that becomes the base of a fabric, and the weave can be woven repeatedly back and forth, left and right. In addition, the warp yarns have a black texture over the weft yarns (warp float). The warp yarn-under-weft (weft float) texture is shown in white. The weave of the 1/2 twill weave of figure 1 has a repeat of 9 squares of 3 warp yarns and 3 weft yarns. The number of the squares of one perfect weave is 9, and the direction of the multiple embossments is the direction of the weft yarn. Therefore, if the weft direction is set to the body length (height) direction of the swimsuit, the number of squares of the resistant yarn perpendicular to the weft direction is 3 of the black-coated warp yarns. It can be seen that the resistance yarn ratio (Rr) was 33.3% as shown in the following formula. This calculation result can be used as an index of the water frictional resistance. Since the water friction resistance is less than 40%, the texture can reduce the water friction resistance by using the weft direction having many floats in the length direction of the swimsuit.

F: number of squares of raised lines in a direction perpendicular to the length (height) direction of the swimsuit in one perfect organization: 3 (stand)

P: number of fully organized squares: 9 (pieces)

Rr＝(F/P)×100＝(3/9)×100＝33.3％

When the front and back surfaces of the woven fabric having the structure of fig. 1 are changed and the back surface is used as the front surface of the swimwear, the twill line shown in fig. 2 is at the upper left in the weave structure diagram, and as described above, one perfect structure of 9 squares of 3 warp yarns and 3 weft yarns is formed. However, if the weft direction is used for the surface of the swimwear in the body length (extension) direction, the number of black squares of the resistant yarn perpendicular to the body length (height) direction is 6. Therefore, the resistance yarn ratio was 66.6%. The proportion of the yarn parallel to the swimming traveling direction becomes smaller, the proportion of the yarn perpendicular to the traveling direction becomes larger, and the water friction resistance becomes larger. In this case, the weft direction is not used for the surface of the swimsuit in the length (height) direction, but the warp direction of the fabric is used for the surface of the swimsuit in the length (height) direction, and the ratio of the resistance yarn is the same as that in fig. 1. In the case of twill weave (twill weave) or satin weave, the ratio of the resistant yarn is reversed between the front side and the back side of the fabric, and therefore care is required when sewing the swimwear. When the back of the twill weave is used for the surface of the swimwear, the warp direction of the fabric is used in the length (height) direction of the swimwear, and the yarn resistance ratio is 33.3%, and the frictional resistance is reduced. When the fabric is cut to obtain sewn parts (parts) of each part, the warp and weft in the body length direction are reversed, and the warp direction is set to the body length (height) direction of the swimwear, thereby being used as a low-friction fabric.

In the case of the 2/1 warp twill weave of fig. 3, if the warp direction with many floats is used in the length (height) direction of the swimwear, the yarn resistance ratio is 33.3%. However, if the weft direction is used in the length (height) direction of the swimsuit, the resistance yarn ratio is 66.6%. Therefore, if the warp direction is used in the length (height) direction of the swimsuit, the water friction resistance can be reduced.

In the case of twill weave or satin weave, it is important to determine whether the front or back side is used, and whether the warp direction or the weft direction is used in the length (height) direction of the swimwear.

It should be noted that the weft twill weave is a name of a fabric having more weft yarns on the surface, and the warp twill weave is a name of a fabric having more warp yarns on the surface, and both are different names of twill weave.

The satin fabric passes through the front and back surfaces in the same manner, and the warp yarns and the weft yarns reverse in floating and sinking. In the present invention, it is important to produce a fabric for swimwear in which the percentage of resistance yarn in the direction perpendicular to the direction of the multiple floats is 40% or less and the direction of the multiple floats is used in the length (height) direction of the swimwear, and to satisfy this requirement, the front and back surfaces, warp and weft of the fabric are selected so as to be favorable for the cuttability of the parts at the time of sewing, and the production cost can be reduced.

A full weave of the plain weave fabric is shown in fig. 4. The total number of squares of one perfect weave was 4, and the number of squares of the resistant yarn perpendicular to the direction of the multiple floats was 2. In the case of a plain woven fabric, the percentage of the resistant yarn in any one direction of the front surface, the back surface, the warp and the weft is 50%, and the water friction resistance is large.

Fig. 5 shows a weave pattern of 5 satins. In this case, the water friction resistance can be reduced by using the warp direction as the body length (height) direction which is the direction of water flow, and setting the resistance yarn ratio to 20%.

In the present invention, the woven structure is not limited to twill weave (twill weave) and satin weave, and any structure such as day and night weave and modified weave may be used as long as the percentage of the resistant yarn is 40% or less. In dobby and jacquard fabrics in which a plain weave portion, a twill weave (twill weave) portion, and a satin weave portion are combined, the frictional resistance between the fabric surface and water can be reduced by setting the percentage of resistant yarns in one repeat to be perpendicular to the direction of the many floats to 40% or less and using the direction of the many floats in the body length (height) direction of the swimsuit from the viewpoint of pattern and design.

In addition, by totaling the fabric member portions in the area of the swimsuit corresponding to the amount of the swimsuit used for one piece of swimsuit and setting the percentage of the resistant yarn to an area of 40% or less, the water friction resistance can be kept low, and the object of the present invention can be satisfied.

In the present invention, the total coating coefficient represented by the following formula is preferably 2800 or more. When the total coating coefficient is small, the number of the interlaced points is small, the binding of the weaving yarn is small, and the problems of mesh twisting and snagging occur, so that the coating coefficient is more preferably 3000 or more. More preferably 3200 or more.

cf＝〔√Dx×My〕+〔√Dy×My〕···(II)

cfx≥cfy···(III)

cf: total coating coefficient

cfy [ √ Dy × My ]: coating coefficient in direction with less emboss

And Dx: fineness of yarn in direction with many embossments: fineness (dtex) of covering yarn using spandex as core yarn and synthetic fiber filament as sheath yarn

Dy: fineness of direction with few wrinkles: fineness (dtex) of covering yarn using spandex as core yarn and synthetic fiber filament as sheath yarn

Mx: fabric density in multiple directions of embossments (root/2.54 cm)

My: fabric density in the direction of few embossments (root/2.54 cm)

From the viewpoint of further reducing the frictional resistance between the fabric surface and water, the coating coefficient in the direction in which the number of embossments of the warp or weft is large is preferably made larger than the coating coefficient in the direction in which the number of embossments is small on the fabric surface, and formula (III) is preferably satisfied.

The direction of the large number of floats referred to herein means a direction of yarns having a large number of floats on the surface of the fabric in one weave pattern. Therefore, the warp direction or the weft direction is formed by the woven structure or the front and back surfaces of the fabric. In particular, in sewing, it is necessary to pay sufficient attention to the fact that the direction of the many raised grains is used on the surface of the swimsuit in the length (height) direction.

The water friction resistance is further reduced by making the coating coefficient in the body length (height) direction larger than the coating coefficient in the body width direction perpendicular to the body length (height) direction, and complementing the effect of reducing the above-mentioned resistance yarn ratio to 40% or less.

More preferably, the water friction resistance is further reduced by setting the ratio of the coating coefficient in the direction of the large number of embossments divided by the total coating coefficient to 55% or more. More preferably 60% or more. However, if it is too large, the warp and weft balance of the woven fabric is deteriorated, mesh twisting and miss stitch are likely to occur, and the warp and weft balance as a tensile force of the swimwear is also deteriorated.

The warp yarn fineness and the weft yarn fineness represented by the above numerical expressions are the total fineness after a yarn in which a core yarn and a sheath yarn are combined is made into a woven fabric and dyed. In the case of using a single yarn without using a covering yarn, the fineness of the single yarn after the single yarn is made into a woven fabric and dyed, and in the case of using a doubled or twisted yarn, the fineness of the doubled or twisted yarn after the doubled or twisted yarn is made into a woven fabric and dyed. That is, the apparent fineness of the fiber obtained by decomposing the woven fabric of the final product and taking out the fiber was measured by the method described in examples.

The fabric density is likewise the density of the fabric after the fabric has been made and dyed.

In addition, when the density of the part in the texture of the tear-resistant fabric or the like is changed to a sparse part or a dense part, the density of the part occupying 50% or more of the area of one complete texture part out of the thick part and the dense part is set to the above range, whereby the low water resistance which is the object of the present invention can be obtained.

When 2 or more kinds of covering yarns are used in an array as the weaving yarn, the total covering coefficient and the covering coefficient may be determined using the fineness and the density obtained by simply averaging the number and the fineness of the fibers arranged in one complete structure portion.

When the weave portion is changed by a dobby fabric, a jacquard fabric, or the like, the frictional resistance between the fabric surface and water can be reduced by setting the total coating coefficient of one repeating repeat perfect weave to 2800 or more, the coating coefficient in the height (height) direction to be larger than the coating coefficient in the width direction perpendicular to the length (elongation) direction, and the ratio of the resistance yarn in the direction perpendicular to the direction in which many floats are present to 40% or less.

The weight per unit area of the fabric for swimwear of the present invention is preferably as small as possible, and from the viewpoint of see-through and strength, it is preferably 50g/m²Above, more preferably 70g/m²As mentioned above, the weight and water resistance are increased, and therefore, it is preferably 200g/m²The following.

The thickness of the fabric for swimwear of the present invention is preferably as small as possible, and is preferably 0.15mm or more, and more preferably 0.2mm or more, from the viewpoint of perspective and strength. Further, since the water resistance becomes large when the thickness is large, it is preferably 0.7mm or less. The fabric for swimwear of the present invention is preferably subjected to hydrophobic processing. The hydrophobizing agent used for the hydrophobic processing may be any hydrophobizing agent such as a fluorine-based hydrophobizing agent, a silicone-based hydrophobizing agent, and a paraffin-based hydrophobizing agent, and among them, a fluorine-based hydrophobizing agent is preferable in view of the hydrophobic property. In particular, from the viewpoint of performance, a fluorine-based hydrophobizing agent having 8 or more carbon atoms (so-called C8 hydrophobizing agent) is preferable, and a PFOA-free fluorine-based hydrophobizing agent having 6 carbon atoms (C6 hydrophobizing agent) which does not generate perfluorooctanoic acid (PFOA) is more preferable. In view of the market expectation of non-fluorination, it is more preferable to use the C0 hydrophobizing agent alone or in combination with a silicone-based or paraffin-based hydrophobizing agent.

In order to improve the durability of the hydrophobic property, it is preferable to use a crosslinking agent in combination with the hydrophobic agent. As the crosslinking agent, at least 1 kind of melamine resin, blocked isocyanate compound, glyoxal resin, imine resin, and the like can be used, and the crosslinking agent is not particularly limited.

In the present invention, the frictional resistance between the surface of the woven fabric and water can be further reduced by using a synthetic fiber filament having a plurality of grooves on the surface in the longitudinal direction of the fiber as a sheath yarn and a covering-covered yarn using an elastic fiber as a core yarn. The cross-sectional shape of the synthetic fiber filament having a plurality of grooves and the number of grooves may be arbitrarily set, and from the viewpoint of cost and production stability, the number of grooves on a circular cross-section is preferably 6 to 15, more preferably 6 to 10.

Fig. 11 a and b are schematic cross-sectional views showing examples of cross-sectional shapes of single fibers constituting the synthetic fiber multifilament yarn used for the swimsuit fabric of the present invention. Fig. 11 a is a so-called 8-leaf star-shaped cross section, and has 8-leaf convex portions formed of polymer portions 14 and V-groove void portions 13 formed of concave portions adjacent thereto.

In fig. 11 b, a circular cross section having narrow grooves is shown, and the polymer portion 14 and the void portion 13 having narrow grooves are shown in the same manner as the star-shaped cross section.

The synthetic fiber filament having a plurality of grooves on the surface in the longitudinal direction of the fiber can be easily produced by dissolving the easily soluble component using a fiber produced by core-sheath composite spinning using a polymer of two components to form a slit-like groove. This method is preferable because a precise cross-sectional shape can be produced. The yarn may be produced as a cross-sectional yarn using a cross-sectional spinneret for melt spinning of a single component.

In addition, the depth of the grooves in the cross-sectional shape of the synthetic fiber filament is preferably 1.0 μm to 10.0. mu.m. When the thickness is less than 1.0. mu.m, the effect of improving the hydrophobicity due to the lotus effect (lotus effect) is not easily exhibited, and when the thickness is more than 10.0. mu.m, the strength of the fiber is lowered. The depth 17 of the groove of the star cross-section yarn (star cross-section) can be defined as the depth of a void portion from the intersection of the straight line 15 connecting the end points of the protrusions existing across the groove to the polymer portion 14 of the fiber on the line of the perpendicular line 16, where the perpendicular line 16 is connected to the center point 12 of the cross-section of the synthetic fiber filament perpendicular to the longitudinal direction from the straight line 15 connecting the end points of the protrusions. The center point is defined as the center point of a circle that most circumscribes the tip of the projection at two or more points in the cross section of the fiber polymer section.

The width of the grooves is preferably 1.0 μm to 10.0. mu.m. If the width is less than 1.0 μm, the lotus effect is not easily exhibited, and if the width is more than 10.0 μm, the water is easily immersed in the uneven grooves. The width of the groove can be defined as the length of a straight line 15 connecting the end points of the adjacent protrusions observed when a cross section of a fiber polymer cross section of the synthetic fiber filament is observed in a direction perpendicular to the longitudinal direction of the fiber.

The width of the convex portion formed between two adjacent grooves is defined as the length 25 of a straight line connecting the protrusion 24, which is the end of the convex portion on the groove a side of the convex portion, and the protrusion 25, which is the end of the convex portion on the groove side adjacent to the groove a with the convex portion therebetween, in the case of the circular cross section having narrow grooves in fig. 11d, among the convex portions formed between two adjacent grooves. In the cross section of the star-shaped 8-leaf in fig. 11 a, the protrusions at the ends of both the protrusions are close to each other or overlap each other, and as a result, the width of the protrusion is close to 0. From the viewpoint of water frictional resistance, the width of the convex portion is preferably as close to 0 as possible, and the convex portion is desirably apex-shaped.

Since the fiber surface is grooved to form unevenness, and the lotus effect described later shows high hydrophobicity, the grooved portion is filled with air in water, and the individual walls of the fiber surface do not come into contact with water due to the air film, so that the water frictional resistance with the fiber disappears. The fiber surface is only a part of the individual wall of the convex portion, which is a portion that comes into contact with water. By reducing the projections in contact with water as much as possible, the water frictional resistance becomes small. However, if the protrusions form acute angles, the fiber surface fibrillates due to friction between the fiber surface and various individual surfaces when worn, and the monofilaments are likely to split. Since cracks are likely to occur and the fiber surface is likely to whiten, the width of the projection is preferably 1.0 μm or more, and preferably 10.0 μm or less. When the width of the convex portion is larger than 10.0 μm, it is difficult to exhibit a lotus effect described later and to maintain high hydrophobicity. In the case of a product for which wearing durability is recognized, it is preferable to widen the width of the convex portion to improve wear durability. In addition, in the case where speed-based recording is emphasized more than wear durability as a competitive aspect, the setting can be arbitrarily made for the purpose of reducing the width of the convex portion or the like.

In the present invention, it is preferable to use synthetic fiber filaments having narrow grooves as the synthetic fiber filaments having a plurality of grooves on the fiber surface in order to prevent water from entering the uneven grooves and further prevent fibrillation by abrasion. The narrow grooves are preferably grooves having a wide width portion on the outer periphery of a single fiber, and preferably a plurality of grooves are present, for example, when a cross section perpendicular to the longitudinal direction of the fiber is observed.

Specifically, synthetic fiber filaments satisfying the following expression of the groove entrance width (SWmin), the width of the wide groove portion (SWmax), and the groove depth (SH) with respect to the fiber diameter (D) can be suitably used.

The narrow type here means a form in which the width of the internal space of the groove is wider than the width of the entrance of the groove on the fiber surface in the cross section of the fiber (an example is shown in fig. 11 b).

(SWmax)/(SWmin)≥1.3

0.15≤(SH/D)≤0.25

In the above, the width of the entrance of the groove (SWmin), the width of the wide portion of the groove (SWmax), the diameter of the fiber (D), and the depth of the groove (SH) can be determined in the following manner.

That is, the inlet width (SWmin) of the groove can be defined as the length of a straight line 15 connecting the end points of the adjacent protrusions observed when a cross section of a fiber polymer cross section perpendicular to the fiber direction, which is a synthetic fiber filament, is observed, similarly to the inlet width of the V-shaped groove of the star-section yarn shown in fig. 11 a. Therefore, in the case of the narrow groove, the length of the end point of the protrusion connecting the adjacent convex portions is set. The wide width portion width 18(SWmax)) of the groove is a maximum position when a length orthogonal to the center line of the groove is measured from the outer peripheral portion toward the center of the fiber along the center line 19. The diameter of the circumscribed circle 22 of the convex portion is defined as the diameter (D)20 of the fiber. The depth 21(SH) of the groove in the round-section yarn having narrow grooves means the distance between the center line of the groove and the intersection of the circumscribed circle 22 of the convex portion and the inscribed circle 23 of the groove portion. The circumscribed circle 22 is a perfect circle that most circumscribes at least two points at the tip of the convex portion in the cross section of the core-sheath composite fiber, and the inscribed circle 23 is a perfect circle that most circumscribes at least two points at the tip (bottom) of the groove portion.

As the round cross section having narrow grooves of the present invention, synthetic fiber filaments having an internal void width satisfying the following formula can be preferably used. That is, a synthetic fiber filament may be used in which the end of the protrusion forming the entrance of the groove is acute-angled, and the width (Pout) between adjacent protrusions and the width (SWmin) of the entrance of the groove, and the width (Pout) of the adjacent protrusions and the width (Pmin) of the bottom surface of the adjacent groove satisfy the following expression. The width (Pout) of the protrusion is a distance between the tip of one protrusion 24 linearly connecting a certain groove and the tip of a protrusion closer to the protrusion 24 among the protrusions of the adjacent grooves, and is represented by the width 25 of the convex portion in fig. 11 d. The width 26(Pmin) of the bottom surface of the adjacent groove is a distance between points of portions of the adjacent groove portions that correspond to the tangent points of the inscribed circle 23 with the protrusion portions therebetween.

(Pout)/(SWmin)＝2～10

(Pout)/(Pmin)≥1.3

As described above, the synthetic fiber filament having these grooves can be obtained by eluting the sheath component of the fiber produced by core-sheath composite spinning using a solvent. As the core component, polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, polyamide, or the like can be used. As the sheath component, from the viewpoint of simplifying the elution step, a copolyester, polylactic acid, polyvinyl alcohol, or the like, which exhibits easy elution in an aqueous solvent, hot water, or the like, is preferable, and from the viewpoint of handling and easy dissolution in an aqueous solvent, a polyester, or polylactic acid obtained by copolymerizing polyethylene glycol and a monosodium sulfoisophthalate, alone or in combination, is preferably used.

In particular, when false twisting is performed, the false twisting is performed using a core-sheath composite fiber in a state containing an eluted component, and the eluted component is eluted in a dyeing step after weaving, whereby the groove is not broken in the false twisting, and the slit portion of the groove can be maintained even in a processed yarn. Even in normal spinning without using a composite spinning machine, a slit yarn can be obtained, but in many cases, a groove is broken in false twisting. In the false twisting process, the damage of the groove is inhibited in the core-sheath composite fiber filled with the dissolved component in the groove, and the dissolved component is dissolved by the dyeing process after weaving, thereby maintaining the shape of the groove.

A preferable method of elution and dyeing is to refine, relax and dry the raw fabric, and then thermally fix the width by intermediate setting, and then elute the components of the furrows. Then, dyeing is performed, and reduction cleaning is performed if the material is a polyester material, and fixing treatment is performed if the material is a nylon material, and washing with hot water and drying are performed. Then, a finishing step of performing a hydrophobic treatment and, if necessary, various functional processes is performed.

In addition, since the core yarn of the fabric of the present invention uses an elastic fiber such as polyurethane spandex in combination, it is preferable to use a polyamide that can be dyed with an acid dye that causes few problems in the dyeing step.

In the case where the synthetic fiber filaments used for the covering yarn are core-sheath conjugate fibers, a conventional method in which the elution of the sheath component and the attention of using an elastic fiber such as spandex or the like are taken into consideration can be used in the dyeing step after the production of a woven fabric. For example, the conditions of temperature and width are adjusted in about 3 stages by refining and relaxing while maintaining the spread state to prevent the occurrence of wrinkles, and then the width is fixed by a tenter, and then the sheath polymer of the core-sheath conjugate fiber is removed by caustic soda solution or the like to produce a groove of the synthetic fiber. Then, the fabric for swimwear is obtained by dyeing, fixing, drying, hydrophobing, and finishing.

In addition to the unevenness of the woven fabric surface due to the weave, the unevenness between the monofilaments of the fiber yarn, and the like, further complicated unevenness can be expressed on the woven fabric surface by providing slit-like grooves or the like on the fiber surface. The contact angle of water on the surface of the woven fabric is described by the Wenzel formula shown below, and when the contact angle of the fiber surface is 90 ° or more, the larger the surface roughness of the material, the larger the apparent contact angle, and the more easily water is repelled. This effect is called the lotus effect.

[ Wenzel formula ]

r×cosθ＝cosθ’

r: true surface area/apparent surface area

θ: true contact

Theta': apparent contact angle

However, when wearing as a swimwear, the fabric is stretched in the warp and weft directions and worn, the unevenness caused by the weave of the fabric and the monofilaments of the fiber yarn is flattened as much as possible, the lotus effect is reduced as much as possible, and water is less likely to be repelled than before wearing. In particular, in recent years, in order to improve the surface smoothness of a woven fabric used for swimwear, there is a tendency that a swimwear smaller by 1 size is worn when worn in swimwear or the like requiring a swimming speed, and there is a phenomenon that the surface unevenness of a woven fabric becomes small and apparent hydrophobicity becomes low.

However, by providing a plurality of grooves on the fiber surface, the decrease in hydrophobicity can be suppressed even if the fabric is stretched. Even if the fabric is stretched and curled by yarn processing during wearing, the fabric structure and the processed yarn structure are stretched and flattened, but since the plurality of furrows provided on the surface of the fiber are not stretched and flattened, the lotus effect can be maintained, and the degree of hydrophobicity can be maintained high.

In particular, in a preferred embodiment of the present invention, as the synthetic fiber filament of the sheath yarn, a fiber having a plurality of grooves on the surface in the longitudinal direction of the fiber is used in at least a part of the warp and the weft, and is preferably used so as to be arranged on the surface of the fabric, and is particularly preferably used in a direction in which the number of floats of the warp and the weft increases. That is, by using the fabric for use in swimwear in the length (height) direction, the grooves on the fiber surface are arranged parallel to the direction of travel during swimming, that is, the direction of water flow, and the effect of reducing the frictional resistance between the surface of the fabric for use in swimwear and water can be further greatly increased.

In the above-mentioned fiber subjected to the hydrophobic processing with the grooves formed in the longitudinal direction thereof, the inside of the grooves is filled with air when the fiber is exposed to water, and thus an air film is formed.

Therefore, the water flow on the fiber surface of the swimsuit slides over the air film in the groove portion as if the water were suspended, and the frictional resistance is smaller than that of the fiber surface portion around which the groove is not formed, and is faster than that of the water layer on the fiber surface having no groove. As a result, the water on the surface of the low-speed fibers is entrained in the water flow above the air film in the uneven groove portions. This is considered to be a phenomenon in which water flowing on the surface of the fiber having no grooves flows onto the air film of the groove portion and repeatedly collides with and disperses.

By repeating the above-described collision and dispersion, turbulence is promoted, and peeling of the boundary layer of water in the surface of the swimsuit is suppressed, and the shape (pressure) resistance is also reduced, as in the dimple effect generated by the dimples of the golf ball.

The peel angle of the boundary layer of water, which is the phenomenon described above, can be measured by providing a cylindrical sample stage in the return water tank shown in the examples and mounting a cylindrical fabric sample on the sample stage. Fig. 6 is an outline view showing the concept of the return water tank. The return water tank is composed of two pipes for returning water in the upper and lower water tanks and the water tank. In fig. 6, arrows indicate the direction of water flow. Several grams of nylon particles were mixed into the reflux water tank as tracer particles, and the tracer particles were irradiated with laser light in a dark room state to photograph the angle of separation of the boundary layer of water from the cylindrical sample, and comparative evaluation was performed (an example is shown in b of fig. 12). Fig. 12 is a photograph showing an example of evaluation of the peel angle of the boundary layer of water, and a of fig. 12 is a photograph obtained by setting and photographing a woven fabric for measuring the peel angle according to the measurement method of "(10) measurement of the peel angle of the boundary layer of flowing water in the cylindrical sample mount" described in the examples. Here, the room is not lighted off and the laser is not irradiated. Fig. 12 b is a photograph taken by closing the illumination of the room in the same state and irradiating the room with laser light after being placed in a dark room (the boundary layer peeling angle is measured using the photograph). Fig. 12 a and b show the surface 27 viewed from the top of the cylindrical sample mounting base, and the peel angle of the boundary layer of water was determined as the peel angle 2 of the boundary layer by measuring the angle formed by the line parallel to the flow direction passing through the center point of the circle viewed from the top and the line connecting the center point and the peel point of the flow on the circular sample mounting base installed in the water flow flowing in the direction indicated by the arrow b in fig. 12, i.e., in the direction from right to left. The measurement can be performed by replacing the fabric sample so that the measurement conditions such as the water temperature and the flow rate are the same (the reynolds number is the same), and the measurement can be performed by comparing the values of the peeling angle 28. The larger peeling angle 28 is a state in which the peeling of the boundary layer is suppressed, and the wake of the flow is less likely to form a vortex, and the negative pressure is reduced, as a result of which the shape (pressure) resistance is reduced.

In example 1 in which a fabric satisfying the requirements of the present invention was mounted on a cylindrical sample mount 5 (diameter: 7.5cm, height: 28.0cm), the flow rate was 1.0 m/sec (Reynolds number: 8.3X 10)⁴) The boundary layer peel angle under the same conditions was 124 °, and in the case of comparative examples 1, 2 and 3 in which a woven fabric not satisfying the predetermined resistance yarn ratio of 50% or more of the present invention was installed, the boundary layer peel angle measured under the same conditions was113-120 DEG, and the stripping angle of the boundary layer is reduced. That is, the shape (pressure) resistance becomes large. In particular, in comparative example 3 in which the ratio of the resistant yarn was as high as 66.6%, the peel angle of the boundary layer was the smallest at 113 °, and the shape (pressure) resistance was the highest.

In addition, the water friction resistance is simultaneously compared with the 7.0N/m of the embodiment 1²In comparison, the comparative examples 1, 2 and 3 are as high as 7.4 to 7.8N/m²。

As is clear from the dimple effect of a golf ball, the peel angle of the boundary layer increases and the shape resistance (pressure resistance) decreases when the boundary layer has a moderate concave-convex dimple. However, if the uneven pits are provided, the smoothness of the surface is deteriorated, and the surface area is larger than that in the state without the uneven pits, so that the frictional resistance is increased. The frictional resistance greatly affected by the smoothness of the surface is opposite to the shape (pressure) resistance affecting the peeling angle of the boundary layer due to the appropriate unevenness. Further, it was found that the fabric for swimwear of the present invention having a resistance yarn ratio of 40% or less has the effect of reducing the frictional resistance and the shape (pressure) resistance. Further, in the case of using a fiber in which grooves are formed in the longitudinal direction of the fiber and water repellent processing is performed, an air layer is formed in the grooves and water slides over the air layer, so that the frictional area with the surface of the fiber is substantially reduced, the frictional resistance is also reduced, and the shape resistance (pressure resistance) can be reduced.

That is, the swimwear is particularly effective for women having a particularly large difference in the cross-sectional area of the human body in the advancing direction during the swimming match. By arranging a woven fabric in which a direction having many floating grains is used in the traveling direction at a portion where a boundary layer of water is likely to peel, such as the chest, the waist, and the hip, not only frictional resistance but also shape (pressure) resistance is reduced.

It is also preferable that a core-spun covered yarn including an elastic fiber as a core yarn and a synthetic fiber filament as a sheath yarn is disposed in at least one of the warp and the weft which has a large number of embossments on the surface of the fabric, and the direction in which the number of embossments is large is set to the body length (height) direction of the swimsuit, so that the frictional resistance and the shape (pressure) resistance can be reduced as much as possible. Further, it is more preferable from the viewpoint of reducing the frictional resistance and the shape (pressure) resistance even more by using a covering yarn in which synthetic fiber filaments having uneven grooves are used as a sheath yarn and an elastic fiber such as spandex as a core yarn, and using this direction as a running direction.

In the case of the fabric of the present invention having the property of reducing both resistances by using one raw material for both resistances of shape (pressure) resistance determined by the characteristics of water friction resistance and peel angle of the boundary layer, one raw material can be applied to all parts of the swimsuit without selecting the parts when sewing the swimsuit, which is convenient to use, and the raw material does not need to be switched depending on the disposition, and the number of seams can be reduced.

Conventionally, a material having low frictional resistance is selected for a relatively smooth portion of the body from the abdomen to the waist and front and rear portions of the front of the thighs in the swimming match, and a portion having a large change in shape such as the chest and the buttocks has a large shape resistance (pressure resistance) due to boundary layer peeling, and therefore, a plurality of materials are used separately for this portion as the case may be, for example, a material for preventing boundary layer peeling is selected. In this case, the number of joints increases because of the need to change the raw material, and the increase in water resistance due to the increase in joints becomes a problem. The fabric for swimwear of the present invention, which can reduce the seams, is preferable because it also has the effect of reducing the resistance caused by the seams.

The fabric for swimwear of the present invention has excellent stretch properties, can adjust the body shape, has an effect of reducing the frictional resistance between the surface of the fabric and water, and has an effect of forming an air film by holding air in the grooves provided in the synthetic fiber filaments, so that the shape resistance (pressure resistance) can be reduced by the effect of increasing the peel angle of the boundary layer of water, and thus can be suitably used for swimwear such as swimwear, wetsuit, and the like.

Examples

The present invention will be described in further detail with reference to examples below, but the present invention is not limited to the examples. The evaluation in the examples can be obtained by the following method.

(1) Weight per unit area

For the weight per unit area, according to JIS L1096: 2010, method A of 8.3.2, the mass per unit area in the standard state (20 ℃ C., 65% RH) was measured. That is, 3 test pieces of 200 mm. times.200 mm were collected, and the mass (g) after leaving in a standard state for 1 day was measured to determine the mass per 1m by the following formula²Mass (g/m) of²) The average value was calculated and rounded to 1 digit after the decimal point.

Sm＝W/A

Wherein Sm: mass per unit area (g/m) in the standard state²)

W: mass (g) of test piece in Standard State

A: area (m) of test piece²)

(2) Thickness of

For the thickness, according to JIS L1096: 2010, 8.4, the thickness of the humidity-conditioned sample obtained by the method a was measured at 5 different positions for 10 seconds at a constant pressure of 23.5kpa using a thickness gauge, and the average value was calculated.

(3) Ratio of resistance yarns

From a weave pattern of the fabric, squares with warp yarns above the weft yarns are darkened and squares with warp yarns below the weft yarns are left blank. On the basis of this, the direction of the multiple embossings was confirmed. When the weft floats much, the weft direction is taken as the body length (height) direction, and the number of squares (F) perpendicular to the body length direction is counted. In addition, all the squares (P) are counted, and the resistance yarn ratio is calculated by the following formula.

Rr＝(F/P)×100

Rr: percent resistance yarn (%)

F: number of squares of floating grain in a direction perpendicular to the length (height) direction of the swimsuit in one perfect organization

P: number of a fully organized complete block

(4) Coefficient of coating

(4-1) apparent fineness of decomposed yarn of Fabric

The warp and weft yarns were drawn out from the fabric, and the apparent fineness thereof was measured in accordance with JIS L1096: "method for measuring apparent fineness of fiber taken out of clothing" in appendix H of 2010 was measured.

In the case of a processed product obtained by coating a resin and laminating a coating film, the apparent fineness of fibers taken out of a clothing material from which non-fibrous substances have been removed was measured by the method described in ISO 1833-1. In the case of a dyed processed product (including hydrophobic processing and softening processing) which is not subjected to resin processing, the measurement was carried out by the method described in "measurement of apparent fineness of fiber taken out from clothing from which non-fibrous matter was not removed" in chapter 2.

The mass of the yarn was measured by adjusting the moisture balance under a standard condition (20 ℃ C., 65% RH) (method A), and the measurement was determined by the following equation. The number of n is 40 or more.

Ld＝Ws/L×n

And Ld: apparent titer (tex) of yarn adjusted at standard condition

Ws: mass (g) of yarn taken out of cloth

L: average value (m) of straightened length

n: number of yarns weighed

In the case of the core spun yarn, the apparent fineness is measured in the state of being spun, without separating the yarn drawn out of the clothing into the elastic fiber of the core yarn and the synthetic fiber filament of the sheath yarn.

(4-2) Density

For the density of the fabric, JIS L1096: 2010, appendix F, method B (fabric decomposition mirror), measures the number of yarns per 1cm, converted to 1 inch (2.54 cm).

The number of measurements was averaged to 3 warps and wefts.

(4-3) coating factor

The measurement results of the apparent fineness and density were substituted into the following formulas to calculate.

cf＝〔√Dx×My〕+〔√Dy×My〕

cf: total coating coefficient

cfx ═ Dx × My ]: coating coefficient in multi-direction of embossments

cfy [ √ Dy × My ]: coating coefficient in direction with less emboss

Dx: fineness (dtex) of weaving yarn in multi-direction of raised grain

Dy: fineness (dtex) of weaving yarn in direction with less float

Mx: multi-directional warp density (root/2.54 cm)

My: fabric density in the direction of few embossments (root/2.54 cm)

(5) The depth of the grooves on the monofilament surface of the fiber, the width of the protrusions, and the width (μm) of the entrance of the grooves

(SWmax): width of the wide width part of the groove, diameter of the fiber (μm), (SWmax)/(SWmin) (ratio of width of the wide width part of the groove/width of the entrance of the groove)

The yarn section was photographed at 1500 times using a scanning electron microscope (manufactured by Hitachi High Technologies, model S-3400N). During this imaging, the operation management is performed by measuring the height of each of the concave and convex portions, the interval between adjacent convex portions, the width of each of the convex portions, and the like. The value measured to 0.01 μm and rounded to 1 decimal place is expressed as the average of 10 measurement results.

(6) Degree of hydrophobicity

For the degree of hydrophobicity, according to JIS L1092: 2009 (7.2 degree of hydrophobicity test) (shower test) 3 samples of about 200mm × 200mm were collected, and 250ml of water was introduced into a funnel using a hydrophobicity tester so that the longitudinal direction of the sample was parallel to the water flow, and the water was sprayed on the sample for 20 to 25 seconds. Next, the sample holder was removed from the apparatus, one end of the sample holder was held horizontally, the surface side of the test piece was faced downward, the other end was gently pressed against a hard object once, water was dropped, and the other end rotated by 180 ° was held, and the same operation as before was performed to drop excess water. And (4) still placing the sample in the holding frame, comparing the wet state of the sample with the comparative sample, and judging.

For washing, a pulsator type washing machine was used under washing conditions of symbol number 142(C4M method) according to JIS L0001-2014, and washing water temperature was 40 ℃. The hydrophobicity of the samples treated before and after 20 washes was determined.

Level 1: the surface was observed to be entirely wet.

And 2, stage: it indicates that half of the surface was wet, and that small wettings one by one showed a wet state of the cloth.

And 3, stage: indicating that the surface is saturated with small drops of moisture.

4, level: indicating that the surface is not wet, but has small water droplets adhered thereto.

And 5, stage: the surface is not wet and no water drops are attached.

(7) Elongation percentage

Elongation according to JIS L1096: 2010, 8.14 tensile elongation a method (tape cutting method). That is, 3 test pieces of 50mm width by 300mm length were taken in the warp direction and weft direction from a sample adjusted in temperature and humidity to a standard state, and the elongation under load of 14.7N under the conditions of a jig interval of 200mm and a tensile speed of 200 mm/min was determined by the following equation using a constant elongation rate tensile tester.

Ep＝(L1-L)/L

Ep: elongation at constant load (%)

L: length between original marks (mm), 200mm

L1: length (mm) under load of 14.7N

(8) Evaluation of abrasion resistance

For the abrasion test, JIS L1076: 2012 "method for pilling test of woven and knitted fabrics", the bottom area of the upper holder was set to about 13cm²The test fabric was fixed to the upper holder and the lower friction plate with the number of rubbing times set to 90rpm and the pressing load set to 7.36N, and then abraded for 10 minutes. After the abrasion, the presence or absence of surface change and fibrillation of the fabric attached to the upper holder was observed with a stereomicroscope.

(9) Determination of Water Friction resistance in smooth sample mounting plates

The water frictional resistance when the swimwear fabric was stretched by 15% in each of the running direction and the direction perpendicular to the running direction was measured using the return water tank shown in fig. 7. Fig. 7 is a side view of an apparatus for explaining the measurement of water frictional resistance using a smooth sample plate in a return water tank, and fig. 8 is a schematic view for explaining a method of sewing a sample attached to the smooth sample plate.

First, a fabric sample was cut into a square shape having a body length (height used for swimwear) direction of 0.867m and a body width (width used for swimwear) direction of 0.634 m. Next, the front surface was set to the inside, the center portion in the body width (width) direction 7 used for the swimsuit was folded in two as shown in a of fig. 8, and after being folded, the end portion 8 sewn in the direction perpendicular to the body length (height) direction 6 used for the swimsuit was set to the hem 0.6cm as shown in b of fig. 8, and was sewn into a bag shape with a seam using nylon yarn.

The sewn hem was turned upside down and pressed with an iron, and the hem was placed on the inner side of the bag-like sample, and the surface of the fabric was set to the surface side of the fabric sample. The sample fixing line 9 is marked at a position of 10cm above with an oil marker or the like. Then, a smooth sample-mounting plate 1 made of stainless steel (draft: 0.25m, length: 1.0m, thickness: 0.006m) was inserted through an opening 10 of the sample sewn into a bag shape, and the sample was stretched so as to cover the smooth sample-mounting plate 1.

The sample fixing line 9 marked on the upper portion of the sample was attached to the sample fixing position of the smooth sample mounting plate 1 in a matching manner, and the sample fabric was stretched by 15% in both the flow direction and the direction perpendicular to the flow direction. In this state, the upper opening 10 is fixed to the smooth sample mounting plate 1 made of stainless steel by a rubber tape, a clip, or the like. A smooth plate and a load cell (strain gauge) 2 capable of measuring the shear stress of the water flow are attached to the portion to which the smooth sample attachment plate is fixed.

The water recirculation tank has a wave-proof top cover through which a plurality of holes having a diameter of about 5cm are passed, and a long hole having a length of 1.1m and a width of 0.015m is provided so that the upper portion of the smooth sample mounting plate made of stainless steel does not contact the top cover portion. And injecting water to a position higher than the top cover by about 3-5 cm. With this top cover, even if the flow speed of the return water tank is increased, the generation of waves in the front portion of the smooth plate can be prevented, and the frictional resistance of the smooth plate covered with the fabric sample can be measured without being affected by the waves.

The flow rate of water in the return water tank can be set arbitrarily by the rotation of the screw incorporated in the lower part of the return water tank. The flow rate can be measured by a pitot tube 3 installed in a water tank. In addition, a water temperature meter is attached to measure the water temperature. In this state, the return water tank is installed in a room in which the temperature and humidity of the room can be arbitrarily set. The temperature of water in the water tank can be set arbitrarily by adjusting the indoor temperature and humidity.

The total Resistance (RT) of the smooth sample-mounted plate 1 covered with the fabric sample was measured with the water temperature set at 25 ℃ and the flow rate set at 2.0 m/sec.

3 bag-shaped fabric samples were prepared, the resistance at a flow rate of 2.0 m/sec was measured 3 times, the arithmetic mean of the measurement data was calculated, and the value obtained by converting the draft area of both sides by the following formula was defined as the frictional resistance RF (unit: N/m)²)。

RF＝(RT-RD)/A

RF: frictional resistance (N/m)²)

A: the total area of the front and back surfaces of the water-impregnated portion of the smooth sheet was 0.25X 1.0+ 0.25X 1.0 ═ 0.5m²(m²)

RT: total resistance (N) of a smooth plate fitted with a sample of Fabric

RD: thickness induced drag increase (N)

RD＝0.486×ρ·x·V²/2

ρ: density of water 997 (kg/m) at 25 ℃³)

x: the projected area (thickness × draft) of a plane perpendicular to the water flow is 0.006 × 0.25 — 0.0015m²(m²)

V: speed of Water 2.0 (m/sec)

The reynolds number indicating the state of the fluid flow is obtained by the following equation.

Re＝VL/ν

Re: reynolds number (-)

V: average velocity of fluid (m/sec)

L: representative length: length of plate (m)

V: dynamic viscosity coefficient of water (m)²Second)

(10) Determination of peel angle of boundary layer of flowing water in cylindrical sample mounting stage

The peel angle of the boundary layer of running water when the fabric for swimwear was stretched by 15% in the running direction and in the direction perpendicular to the running direction was measured using a backflow water tank used for measuring the water frictional resistance, by using a device in which a vinyl chloride resin cylindrical sample mounting base 5 (diameter: 7.5cm, height 28.0cm) shown in fig. 9 was mounted on the top cover 4 at the position of the center portion of the water tank. Fig. 9 is a side cross-sectional view of an apparatus for explaining measurement of a peel angle of a boundary layer of flowing water using a cylindrical sample mounting stage in a return water tank.

The top cover 4 has a plurality of holes having a diameter of about 5cm, and water is injected to a position higher by about 3 to 5cm than the top cover 4. The roof cover 4 is used to eliminate the influence of wave-making resistance, and the roof cover 4 prevents the generation of waves and eliminates the influence of waves even if the flow speed of the return water tank is increased.

First, a fabric sample was cut into a square shape having a length (height) direction 6 of 21.7cm for use in swimwear and a width (width) direction 7 of 29.3cm for use in swimwear. Next, the fabric surface was set inside, the center portion in the body width (width) direction 7 used for the swimsuit was folded in two as shown in a of fig. 10, and after folding, the end portion 8 sewn along the body width (width) direction 7 used for the swimsuit was provided with a 0.6cm hem as shown in b of fig. 10, and was sewn into a tubular shape with the upper and lower portions open 11 using a nylon yarn stitch.

The hem was placed on the inside of the tubular sample by inverting the hem with one side being poured and pressed with an iron, and the surface of the fabric was set to be the surface side of the fabric sample. In addition, the sample fixing thread 9 is marked with an oil marker or the like at a position of 5.0cm in the lower part of the fabric sample for alignment with the mounting position to the cylindrical sample mounting stage 5. The cylindrical sample mounting table 5 is stretched so as to cover the sample sewn into a cylindrical shape. The end of the fabric sample was aligned with the end of the upper part of the cylindrical sample mount 5 and secured tightly with a rubber band. Next, the sample fixing thread 9 marked on the middle fabric sample and the lower end of the cylindrical sample mounting table 5 were aligned with the lower part of the cylindrical sample mounting table 5 and fixed tightly with a rubber band. In this state, the sample fabric was stretched by 15% in both the water flow direction and the direction perpendicular to the water flow direction.

The water tank was operated in the same manner as in the frictional resistance measurement using the smooth sample mounting plate 1.

The peel angle of the boundary layer of flowing water was measured with the water temperature set at 25 ℃ and the flow rate set at 1.0 m/sec. Since the normal illumination state is such that the boundary layer of the clear water is not peeled off as in the photograph shown in a of fig. 12, trace particles (polyamide 10 μm particles, specific gravity 1.02) are appropriately added to the flow water, the illumination of the room in which the return water tank is installed is turned off to a dark room state, and then the cylindrical sample mount 5 is irradiated with Laser light (PIV Laser G150 manufactured by katokkon co., ltd.) in a direction crossing the outer side of the transparent window of the return water tank, and a camera is attached to the upper portion of the return water tank to photograph the flow water state in the vicinity of the surface 27 as seen from the upper portion of the cylindrical sample mount as in b of fig. 12. The exposure of the camera and the speed of the controller (japanese: シッター) at the time of shooting are appropriately adjusted. The angle formed by a line parallel to the flow direction passing through the center point of the circle as shown in b in fig. 12 and a line connecting the center point and the peeling point of the flow is used as the peeling angle 28 of the boundary layer.

A 3-cylinder-shaped fabric sample was prepared, measured 3 times, and the arithmetic mean of the measurement data was calculated as the boundary layer peeling angle (°).

Re＝VL/ν

Re: reynolds number (-)

V: average velocity of fluid (m/sec)

L: representative length: diameter of cylinder (m)

V: dynamic viscosity coefficient of water (m)²Second)

[ example 1]

For the warp yarn, a chlorine-resistant LYCRA "LYCRA-25B" 44dtex (PU44) made by Toray Opelontex Co., Ltd. was used as the core yarn, and a nylon false twist processed yarn (nylon yarn 1) made of 17dtex and 7 filament semi-dull circular cross section was used as the sheath yarn, to prepare a single core-spun yarn having a draft ratio of the core yarn of 3.5 times and a twist factor of 9788 of the twist number 1800T/M. For the weft, a chlorine-resistant LYCRA "LYCRA-25B" (PU33) having a LYCRA value of 33dtex was used as the core yarn, and a 17dtex, 7-filament, semi-dull, round-section nylon false-twist yarn (nylon yarn 1) was used as the sheath yarn, and a single-core spun yarn having a twist factor of 9768 was produced with a twist number of 1900T/M, similarly to the warp yarn. An 1/2 twill weft fabric was produced by a rapier loom, and the raw fabric was subjected to 3-stage relaxation refining in a spread state and then to pretreatment (preset). Then, after dyeing with an acid dye using a liquid flow dyeing machine, drying was performed. Subsequently, the resin composition was immersed in a non-fluorine hydrophobic processing liquid having the following formulation, wrung out with a squeezing rate of 60% using a mangle, dried at 130 ℃ for 2 minutes, and finally cured at 160 ℃ without applying excessive tension.

The fabric thus obtained was a 1/2 twill weave having a weave pattern shown in FIG. 1, in which the number of warp floats was 3 and the number of weft floats was 6 in a single repeat having a warp density of 216 pieces/2.54 cm and a weft density of 270 pieces/2.54 cm.

By using the weft direction in the length (height) direction of the swimwear, a fabric for swimwear having low water friction resistance can be obtained. The coating coefficient, basis weight, thickness, hydrophobicity and elongation of the obtained fabric were measured, and a bag-like sample was prepared from the obtained fabric, and the fabric was stretched by 15% in the water flow direction and in the direction perpendicular to the water flow direction, and was coated with a smooth sample plate, and the water frictional resistance was measured using a return water tank. In addition, a cylindrical sample was produced in the same manner, and the sample was elongated by 15% in the flow direction and in the direction perpendicular to the flow direction, respectively, and the cylindrical sample mount was covered with the sample to measure the peel angle of the boundary layer. The evaluation results are shown in table 1.

The abrasion resistance was evaluated without any problem, and the fabric had low frictional resistance against water, and was excellent in performance as a fabric for swimwear for sportswear and training.

[ formulation for hydrophobic working ]

5% by weight of "NEOSEED" NR-158(NICCA CHEMICAL CO., LTD (manufactured by LTD))

"BECKAMINE" M-3 (manufactured by DIC CORPORATION) 0.3% by weight

"CATALYST." ACX (manufactured by DIC CORPORATION) "0.3% by weight

1% by weight of isopropanol

Treatment liquid obtained by mixing 93.5% by weight of water

[ example 2]

As a core component, nylon 6 was made into a star-shaped core shown in a of FIG. 11, and as a sheath component, polyethylene terephthalate (melt viscosity: 45 Pa. s) obtained by copolymerizing 8.0 mol% of 5-sulfoisophthalic acid monosodium salt and 10 wt% of polyethylene glycol having a molecular weight of 1000 was used, and a core-sheath composite fiber (star composite yarn 1) of 56dtex 18 filaments (core 30 wt%, sheath 70 wt%, 16.8dtex 18 filaments after elution of the sheath component) was obtained so that 8V-grooves were formed in the vicinity of the outer periphery of a cross section perpendicular to the longitudinal direction of 1 core-sheath composite fiber. Next, as 2 doubled sheath yarns, a single-covered core yarn was produced using a chlorine-resistant LYCRA "LYCRA-25B" 33dtex (PU33) obtained by Toray optilon co., ltd to obtain a core yarn having a draft ratio of 3.5 times and a twist factor of 16280 (which is a reduced factor after elution of the sheath component of the composite spun yarn and has a twist factor of 9768) for the core yarn. This single covered yarn was used for the warp and weft, and an 1/2-weft twill was produced by using a rapier loom in the same manner as in example 1, and this raw fabric was subjected to 3-stage relaxation refining in a spread state, and then subjected to pretreatment. Next, a fabric was obtained by using a liquid flow dyeing machine to remove the sea of the polyethylene terephthalate component by 100% with a 1 wt% aqueous sodium hydroxide solution, and using a covering yarn in which a sheath yarn was a star-shaped cross-section yarn shown in b of fig. 11 and polyurethane spandex was used as a core yarn for the warp yarn and the weft yarn. Then, the fabric was dyed with an acid dye using a liquid flow dyeing machine, dried, immersed in the same non-fluorine hydrophobic processing liquid as in example 1, wrung at an extrusion rate of 60% using a mangle, dried at 130 ℃ for 2 minutes, and finally cured at 160 ℃ without applying excessive tension.

The fabric thus obtained was a 1/2 twill weave structure of the weaving pattern shown in FIG. 1, in which the number of warp floats was 3 and the number of weft floats was 6 in one repeat having a warp density of 208 pieces/2.54 cm and a weft density of 220 pieces/2.54 cm.

The grooves in the fiber cross section after the sheath component of the core-sheath composite fiber was dissolved were observed using a scanning electron microscope. The results are as follows.

The grooves were 8, the width of the groove entrance was 9.2 μm, the diameter of the fiber was 18.5 μm, the depth of the groove was 6.1 μm, and the desired shape was obtained that could maintain a large amount of air layer. The protrusion has a sharp acute angle, and the width of the protrusion (apex) is almost zero, and is substantially 0 μm.

By using the weft direction in the length (height) direction of the swimsuit, a swimsuit fabric with low water friction resistance can be obtained. The coating coefficient, basis weight, thickness, hydrophobicity, elongation and the like of the obtained fabric were measured, and a bag-like sample was prepared from the obtained fabric, and the weft direction of the fabric was set to the water flow direction, and the fabric was stretched by 15% in the direction perpendicular to the water flow direction to coat a smooth sample plate, and the water frictional resistance was measured using a return water tank. Further, a cylindrical sample was produced in the same manner, and the cylindrical sample mount was extended by 15% in the water flow direction and in the direction perpendicular to the water flow direction, respectively, and the peel angle of the boundary layer was measured by covering the cylindrical sample mount with the sample. The evaluation results are shown in table 1.

The abrasion resistance was evaluated, and as a result, some fibrillation was observed in the raised portions, which was the most excellent result from the viewpoints of a large area occupied by the groove portions in the yarn surface of the fabric, a large frictional resistance with water, a large peel angle of the boundary layer, and low water resistance. The wear durability was slightly poor, but the fabric was excellent as a fabric for swimwear for competitive use by top players.

[ example 3]

As the core component, as nylon 6 component, as a sheath component, using 5-sulfoisophthalic acid monosodium salt 8.0 mol% and molecular weight 1000 polyethylene glycol 10 wt% copolymer of polyethylene terephthalate (melt viscosity: 45Pa s), 1 core sheath composite fiber to form 8 groove entrance width narrow, internal width wide narrow groove part of the form shown in figure 11 b, to obtain 84dtex 24 filaments (core 80 wt%, sheath portion 20 wt%, sheath component dissolved 67dtex 24 filaments). Next, a yarn (narrow type composite yarn 2) obtained by false twisting using the core-sheath composite fiber was used as a sheath yarn, and a chlorine-resistant LYCRA "LYCRA-25B" 78dtex (PU78) of Toray opeontex co., ltd was used as a core yarn, to produce a single-covered core yarn having a draft ratio of the core yarn of 3.5 times and a twist factor of 9780 of the twist number 1035T/M. This single covered yarn was used for the warp and weft, and an 1/2-weft twill was produced by using a rapier loom in the same manner as in example 1, and this raw fabric was subjected to 3-stage relaxation refining in a spread state, and then subjected to pretreatment. Subsequently, the polyethylene terephthalate component was subjected to 100% sea removal with a 1 wt% aqueous sodium hydroxide solution using a liquid flow dyeing machine to obtain a nylon 100% fabric. Then, after dyeing with an acid dye using a liquid flow dyeing machine, drying was performed. Subsequently, the substrate was immersed in the same non-fluorine hydrophobic processing liquid as in example 1, wrung out with a squeezing rate of 60% using a mangle, dried at 130 ℃ for 2 minutes, and finally treated at 160 ℃ with curing so as not to apply excessive tension.

With respect to the obtained fabric, 1/2 twill weave of the weave pattern shown in fig. 1, in which the number of floats of the warp yarn was 3 and the number of floats of the weft yarn was 6 in one repeat having a warp density of 138 pieces/2.54 cm and a weft density of 144 pieces/2.54 cm, was obtained.

The grooves of the fiber cross section after the sheath component of the core-sheath composite fiber was eluted were observed using a scanning electron microscope. The results are as follows.

The number of the grooves was 8, the width of the entrance of the groove portion was 0.9. mu.m, the width of the wide portion of the groove was 1.6. mu.m (SWmax/SWmin: 1.8), the entrance of the groove portion was narrow and widened in the center direction of the fiber cross section. The diameter of the fiber was 15.9 μm, and the depth of the grooves was 3.1 μm (SH/D: 0.19), and the fiber had a desired shape capable of sufficiently maintaining an air layer. And the width of the protrusion was 7.8 μm. As a result of the evaluation of abrasion resistance, even when forced abrasion was applied, peeling and collapse of the projections were not observed, and fibrillation was not observed when the projections were caught on the surface of the sample.

By using the weft direction in the length (height) direction of the swimwear, a fabric for swimwear having low water friction resistance can be obtained. The coating coefficient, basis weight, thickness, hydrophobicity, elongation, and the like of the obtained fabric were measured, and a bag-like sample was further produced from the obtained fabric, and the weft direction of the fabric was set to the water flow direction, and the fabric was stretched by 15% in the direction perpendicular to the water flow direction to coat a smooth sample plate, and the water frictional resistance was measured using a backwater gutter. Further, a cylindrical sample was produced in the same manner, and the sample was extended by 15% in the water flow direction and in the direction perpendicular to the water flow direction, respectively, and the cylindrical sample mount table was covered with the sample, and the peel angle of the boundary layer was measured. The evaluation results are shown in table 1.

The fabric has narrow uneven grooves on the yarn surface, and is capable of trapping air even in water, and has a large frictional resistance with water and a large peeling angle of a boundary layer, and is excellent as a swimwear for sports having both low water resistance and durability.

[ example 4]

For the warp yarn, a chlorine-resistant LYCRA "LYCRA-25B" 44dtex (PU44) of Toray optilon co., ltd. was used as the core yarn, and a nylon false twist processed yarn (nylon yarn 2) of 33dtex and 24 filament semi-dull circular cross section was used as the sheath yarn, to prepare a single core-spun yarn having a draft ratio of the core yarn of 3.5 times and a twist factor of 9780 at a twist number of 1500T/M. For the weft, a single core-spun yarn obtained in example 2, that is, a core-sheath composite fiber (star composite yarn 1) of 56dtex 18 filaments (core portion 30 wt%, sheath portion 70 wt%, 16.8dtex 18 filaments after elution of the sheath component) was used as 2 cabled sheath yarns, and a single core-spun yarn having a draft ratio of 3.5 times and a twist factor of 1480T/M of 16280 (wherein the coefficient after elution of the sheath component of the composite spun yarn is decreased and the twist factor is 9768) was used as the core yarn, and a five-ply satin texture was produced using a rapier loom, and then the raw fabric was subjected to 3-stage relaxation refining in a spread state in the same manner as in example 2, and then subjected to preliminary treatment. Subsequently, the polyethylene terephthalate component was subjected to 100% sea removal with a 1 wt% aqueous sodium hydroxide solution using a liquid flow dyeing machine to obtain a nylon 100% fabric. Then, the fabric was dyed with an acid dye using a flow dyeing machine, dried, and then immersed in a non-fluorine-containing hydrophobic processing liquid, and then wrung at an extrusion rate of 60% using a mangle, and then dried at 130 ℃ for 2 minutes, and further subjected to a final treatment at 160 ℃ with maintenance without applying an excessive tension, to obtain a five-satin weave texture of a weave pattern shown in fig. 5, in which the number of floating warps is 20 and the number of floating wefts is 5 in one perfect texture having a warp density of 206 pieces/2.54 cm and a weft density of 190 pieces/2.54 cm.

By using the warp direction in the length (height) direction of the swimsuit, a swimsuit fabric with low water friction resistance can be obtained. The coating coefficient, basis weight, thickness, hydrophobicity and elongation of the obtained fabric were measured, and a bag-shaped sample was further prepared from the obtained fabric, and the fabric was stretched by 15% in the water flow direction and in the direction perpendicular to the water flow direction, and coated with a smooth sample plate, and the water frictional resistance was measured using a return water tank. Further, a cylindrical sample was produced in the same manner, and the sample was extended by 15% in the water flow direction and in the direction perpendicular to the water flow direction, respectively, and the cylindrical sample mount table was covered with the sample, and the peel angle of the boundary layer was measured. The evaluation results are shown in table 1.

As a result of the abrasion resistance evaluation, slight fibrillation was observed in the protrusions, and the yarn length of the weaving yarn parallel to the water flow direction was long, and had furrows, and the ratio of the resistant yarn perpendicular to the water flow direction was as low as 20%, and therefore, the yarn was excellent in terms of high frictional resistance with water, large peel angle of the boundary layer, and low water resistance. Although the abrasion durability was slightly poor, the fabric for swimwear was excellent as a competitive game for top players.

Comparative example 1

A flat fabric having a warp density of 240 threads/2.54 cm and a weft density of 230 threads/2.54 cm was obtained in the same manner as in example 1 except that the woven structure of example 1 was changed to a plain weave fabric. The coating coefficient, the weight per unit area, the thickness, the water repellency, and the elongation of the fabric were measured in the same manner as in example 1, and the water friction resistance due to the smooth sample plate was measured using the weft direction in the length (height) direction of the swimwear using a backflow water tank, and the peel angle of the boundary layer was measured using a cylindrical sample mount. The evaluation results are shown in table 1.

Comparative example 2

A flat fabric having a warp density of 143 pieces/2.54 cm and a weft density of 140 pieces/2.54 cm was obtained in the same manner as in example 3 except that a nylon false twist processed yarn (nylon yarn 3) having a semi-dull circular cross section of 67dtex 24 filaments was used as the sheath yarn of the single core spun yarn and a plain weave was formed. The coating coefficient, basis weight, thickness, water repellency, and elongation of the fabric were measured in the same manner as in example 3, and the water friction resistance due to the smooth sample plate was measured using the weft direction in the height direction of the swimwear (body length) using a backflow water tank, and the peel angle of the boundary layer was measured using a cylindrical sample mount. The evaluation results are shown in table 1.

Comparative example 3

2/1 warp twill fabric having a warp density of 216 pieces/2.54 cm and a weft density of 270 pieces/2.54 cm was obtained in the same manner as in example 1, except that the woven structure of example 1 was changed to 2/1 warp twill fabric. The coating coefficient, the weight per unit area, the thickness, the water repellency, and the elongation of the fabric were measured in the same manner as in example 1, and the water friction resistance due to the smooth sample plate was measured using the weft direction in the length (height) direction of the swimwear using a backflow water tank, and the peel angle of the boundary layer was measured using a cylindrical sample mount. The evaluation results are shown in table 1.

[ Table 1]

[ Table 2]

Description of the reference numerals

1: smooth sample mounting plate

2: load sensor (stressometer)

3: pitot tube

4: top cover

5: cylindrical sample mounting table

6: length (height) direction for swimming suit

7: body width (width) direction used in swimwear

8: end part for sewing

9: sample fixing line

10: opening mouth

11: the upper part and the lower part are both open

12: center point

13: void part

14: polymeric moieties

15: straight line

16: vertical line

17: depth of groove (Star-shaped cross section)

18: width of wide width part of groove

19: center line

20: diameter of fiber

21: depth of groove (round section with narrow groove)

22: circumscribed circle

23: inscribed circle

24: protrusion part

25: width of the convex part

26: width of bottom surface of groove

27: surface observed from the upper part of the cylindrical sample mounting stage

28: peeling angle

Claims

1. A fabric for swimwear, which is an elastic fabric comprising a core-spun covered yarn comprising an elastic fiber as a core yarn and a synthetic fiber filament as a sheath yarn disposed at least in part of a warp yarn and a weft yarn, wherein the fabric for swimwear is a woven structure having a large number of floats in either the warp yarn or the weft yarn on the surface of the fabric, the direction having the large number of floats is defined as the body length (height) direction of the swimwear, and the percentage of resistance yarn in the direction perpendicular to the body length (height) direction represented by the following formula (I) is 40% or less,

Rr＝(F/P)×100···(I)

rr: percent resistance yarn (%)

P: the number (number) of one completely organized square.

2. The fabric for swimwear according to claim 1, which is the stretch fabric, has a total coating coefficient represented by the following formula (II) of 2800 or more, and has a coating coefficient in a direction having many floats of warp or weft and a coating coefficient in a direction having few floats on a fabric surface satisfying the following formula (III),

cf＝〔√Dx×My〕+〔√Dy×My〕···(II)

cfx≥cfy···(III)

cf: total coating coefficient

cfy [ √ Dy × My ]: coating coefficient in direction with less emboss

Dx: fineness (dtex) of weaving yarn in multi-direction of raised grain

Dy: fineness (dtex) of weaving yarn in direction with less floating grain

Mx: fabric density in multiple directions of embossments (root/2.54 cm)

My: fabric density in the direction with few embossments (root/2.54 cm).

3. A fabric for swimwear according to claim 1 or 2, wherein the core-spun covered yarn is arranged at least one of warp and weft that has a large number of embossments on a fabric surface.

4. A fabric for swimwear according to any one of claims 1 to 3, wherein the synthetic fiber filaments are synthetic fiber filaments having a plurality of furrows on a surface in a longitudinal direction of the fibers.

5. The fabric for swimsuits according to claim 4, wherein the synthetic fiber filaments have a depth of the furrows of 1.0 to 10.0 μm, a width of an entrance of the furrows of 1.0 to 10.0 μm, and a width of the protrusions of 10.0 μm or less.

6. A fabric for use in swimwear according to claim 4 or 5, wherein the synthetic filament has a cross-sectional shape in which a groove part is a groove having a wide part and satisfying the following formulae (IV) and (V),

(SWmax)/(SWmin)≥1.3····(IV)

0.15≤(SH/D)≤0.25····(V)

(SWmin): width of entrance of groove (mum)

(SWmax): width (mum) of wide part of groove

D: diameter of fiber (μm)

SH: depth of the grooves (. mu.m).

7. A fabric for swimming suits according to any one of claims 1 to 6, wherein the synthetic fiber filaments are polyamide fibers.

8. A fabric for swimming suits according to any one of claims 1 to 7, which is an elastic fabric having a woven structure at least a part of which is a twill weave of 1/2 picks.

9. A fabric for swimsuits according to any one of claims 1 to 8, which is an elastic fabric having a woven structure at least a part of which is a quinphyllsatin weave.

10. A fabric for swimming wear according to any one of claims 1 to 9, which has been subjected to a hydrophobic treatment.

11. Swimwear comprising the fabric for swimwear according to any one of claims 1 to 10, wherein the direction in which the number of floating streaks is large is the length (height) direction of the swimwear.