SWIMSUIT

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a swimsuit and a fabric for swimsuits.

2. Description of Related Art

Sports clothing and swimsuits having high stretchability are suitable for their uses as swimming outfits. Additionally, a reduced surface friction resistance of swimsuits in water at the time of competitive swimming is a function desired for swimsuits and swim caps. Various stretch fabrics have been proposed as fabrics for swimsuits. JP 2004-332137A proposes providing a hydrophilic portion by printing and thereafter immersing the entire fabric in a water repellent to reduce fluid resistance. The applicant of the present application have proposed a swimsuit that has a water-repelling portion and a non-water-repelling portion arranged like stripes along the body length direction in JP 2006-348398A, proposed providing a plain weaved portion and a double weaved portion continuously on a swimsuit in WO 2015/151820A1, and proposed forming a stripe pattern on a swimsuit by embossing in JP 2017-002417A.

JP 2004-332137A, JP 2006-348398A, WO 2015/151820A1, and JP 2017-002417A are examples of related art.

However, the conventional swimsuits described above have a problem in that the swimsuits have a high surface friction resistance in water.

In order to solve the problem of the conventional technologies described above, the present invention provides a swimsuit that has a low surface friction resistance in water.

SUMMARY OF THE INVENTION

One embodiment of the present invention relates to a swimsuit including a warp knitted fabric that has elasticity and includes an elastic yarn and a non-elastic yarn. The swimsuit includes, in at least a portion of the fabric, a stripe pattern that is continuous in one direction and includes a recessed stripe portion and a protruding stripe portion, and at least a portion of the stripe pattern includes a warp knitted fabric portion formed by a herringbone structure.

The swimsuit according to the present invention, has elasticity and includes a warp knitted fabric including an elastic yarn and a non-elastic yarn. The swimsuit includes, in at least a portion of the fabric, a stripe pattern that is continuous in one direction and includes a recessed stripe portion and a protruding stripe portion, and at least a portion of the stripe pattern includes a warp knitted fabric portion formed by a herringbone structure. With this configuration, it is possible to provide a swimsuit that has a low surface friction resistance in water.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a plan view photograph (80× magnification) showing a fabric for a swimsuit according to an embodiment of the present invention.

FIG. 1B is a photograph (80× magnification) showing a cross section taken along the line I-I in FIG. 1A.

FIG. 2 is a diagram schematically showing the arrangement of a non-elastic yarn in a plan view photograph (5× magnification) of a fabric for a swimsuit according to an embodiment of the present invention.

FIG. 3 is a knitting diagram of a fabric for a swimsuit according to an embodiment of the present invention.

FIG. 4 is a knitting diagram of a fabric for a swimsuit according to another embodiment of the present invention.

FIG. 5 is a diagram schematically showing a device for measuring the fluid resistance of a fabric for a swimsuit according to an embodiment of the present invention.

FIG. 6A is a schematic plan view of a wing-shaped model used in the device for measuring the fluid resistance, and FIG. 6B is a schematic side view of the wing-shaped model.

FIG. 7 is a schematic front view of a swimsuit according to an embodiment of the present invention.

FIG. 8 is a schematic rear view of the swimsuit.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a swimsuit and a fabric for swimsuits. The swimsuit comprises a warp knitted fabric that has elasticity and includes an elastic yarn and a non-elastic yarn. An example of the elastic yarn is a polyurethane elastic yarn. The non-elastic yarn is preferably a polyester fiber yarn made of polyethylene terephthalate or the like, or a nylon fiber yarn made of nylon 6, nylon 66, or the like. The elastic yarn and the non-elastic yarn are preferably filament yarns.

The fabric for the swimsuit includes, in at least a portion thereof, a stripe pattern that is continuous in one direction, and the stripe pattern includes recessed stripe portions and protruding stripe portions and is formed by a V-shaped pattern having a herringbone structure. Not only a structure including protruding portions and recessed portions is formed in the fabric, but also the fabric includes the herringbone pattern, and therefore, the fabric has a low surface friction resistance in water. Moreover, the stripes formed by the protruding portions and the recessed portions have a knitted structure, and therefore, it is possible to form the recessed stripe portions and the protruding stripe portions with a small pitch. If the pitch between adjacent protruding portions in the stripes of the protruding portions and the recessed portions is reduced, the surface friction resistance in water becomes low. However, it is difficult to realize a structure including small protruding portions and small recessed portions with conventional embossing technologies, and it is difficult to further form a herringbone pattern in the structure including small protruding portions and small recessed portions.

The herringbone structure described above is not particularly limited as long as a portion of the structure has a V-shaped pattern formed by twill lines including right twills and left twills that are combined directly or with intervals therebetween. An example of the structure is an atlas stitch. Preferably, the front surface of the structure is a sinker surface of the knitted fabric and the structure includes at least two courses in which the direction of the non-elastic yarn is the same. With this configuration, it is possible to more effectively form the structure including protruding portions and recessed portions realized by the herringbone structure.

An average pitch (rib interval) between adjacent protruding stripe portions is preferably 300 to 1500 μm, more preferably 330 to 1200 μm, and further preferably 350 to 1000 μm. Also, an average width of the recessed stripe portions is preferably 100 to 300 μm, more preferably 110 to 250 μm, and further preferably 120 to 200 μm. It is appreciated that by setting the average pitch as above, it is possible to form the recessed stripe portions and the protruding stripe portions with a small pitch to reduce the water flow resistance.

An average height difference (depth) between the recessed stripe portions and the protruding stripe portions is preferably 50 to 500 μm, more preferably 80 to 400 μm, and further preferably 100 to 350 μm. It is appreciated that by setting the average height difference as above, it is possible to form the recessed stripe portions and the protruding stripe portions with a small pitch to reduce the surface friction resistance in water.

Preferably, the fabric for the swimsuit is a stretchable knitted fabric including a synthetic fiber multifilament yarn as the non-elastic yarn and a polyurethane (spandex) fiber yarn as the elastic yarn.

Preferably, a water repellent is applied to the entire surface of the fabric for the swimsuit. The water repellent used for water-repelling processing can be any water repellent, for example, a fluorine-based water repellent, a silicone-based water repellent, or a paraffin-based water repellent, but in view of market circumstances in which it is desired to exclude the use of fluorine, it is more preferable to use a water repellent that is not a fluorine-based water repellent; for example, it is more preferable to use a hydrocarbon-based water repellent, for example, a paraffin-based water repellent or an acrylic water repellent, or a silicone-based water repellent alone or in combination.

Preferably, a crosslinking agent is used in combination with the water repellent to improve durability of the water-repelling properties. The crosslinking agent is not particularly limited, and it is possible to use at least one of a melamine-based resin, a block isocyanate-based compound, a glyoxal-based resin, an imine-based resin, etc., as the crosslinking agent.

The elongation percentage of the fabric for the swimsuit measured in accordance with the method A of the JIS 1096 (2010) (cut strip method), (load: 17.7 N (1.8 kg), width: 5 cm) in both the length direction and the width direction is preferably 60% to 180%, more preferably 70% to 170%, and further preferably 80% to 160%. It is appreciated that under this condition, the swimsuit can have an improved fit and can be easy to wear and take off.

The thickness of the fabric for the swimsuit is preferably 0.8 mm or less, more preferably 0.7 mm or less, and further preferably 0.6 mm or less. It is appreciated that under this condition, it is possible to obtain a swimsuit that is thin and has a low resistance in water. When the swimsuit is sewn, lining is provided in a portion of the swimsuit, for example, a crotch portion, and the total thickness of the fabric (outer material) for the swimsuit and the lining is preferably 0.8 mm or less.

The fabric for the swimsuit according to the present invention is produced by knitting a warp knitted fabric using a warp knitting machine that includes two or more reeds. At this time, the non-elastic yarn is supplied to a front reed and a middle reed, and the elastic yarn is supplied to a back reed. The non-elastic yarn and the elastic yarn can be used appropriately in the middle reed in accordance with needs. Thus, a herringbone stripe pattern including the recessed stripe portions and the protruding stripe portions is formed with the non-elastic yarn.

In the swimsuit according to the present invention, the stripe pattern formed by the herringbone structure is arranged along the height direction (length direction) of a human body. In this case, the water flow resistance can be reduced. The swimsuit can be a swimsuit for competitive swimming and is preferably produced in a size that is 20% to 40% smaller than a standard size of a human body. In this case, the swimsuit can fit well on the human body. Examples of the standard size of a human body include Japanese standard sizes defined by Association of Japan Sporting Goods Industries (JASPO) shown in Tables 1 to 3 below. Table 1 shows men's/unisex sizes, Table 2 shows ladies' sizes, and Table 3 shows junior sizes.

TABLE 1
Size	Height (cm)	Chest measurement (cm)	Waist (cm)
SS	157-163	81-87	67-73
S	162-168	85-91	71-77
M	167-173	89-95	75-81
L	172-178	93-99	79-85
O	177-183	97-103	83-89
XO	182-188	101-107	87-93
2XO	187-193	105-111	91-97
3XO	192-198	109-115	95-101

TABLE 2
Size	Height (cm)	Chest measurement (cm)	Waist (cm)
SS	147-153	74-80	55-61
S	152-158	77-83	58-64
M	157-163	80-86	61-67
L	162-168	83-89	64-70
O	167-173	86-92	67-73
XO	172-178	89-95	70-76

TABLE 3
Size	Height (cm)	Chest measurement (cm)	Waist (cm)
120	115-125	57-63	51-57
130	125-135	61-67	53-59
140	135-145	65-72	54-62
150	145-155	70-78	58-66
160	155-165	76-84	62-70
JS	115-135	—	—
JM	125-145	—	—
JL	135-155	—	—
JLL	145-165	—	—

The total fineness of the elastic fiber yarn used in the present invention is preferably 22 to 156 decitex. Preferably, the non-elastic fiber yarn has a total fineness of 20 to 100 decitex and a single fiber fineness not larger than 0.1 to 3 decitex. From the viewpoint of reducing the weight, the mass per unit area (basis weight) of the fabric is preferably 200 to 300 g/m², more preferably 210 to 290 g/m², and further preferably 220 to 290 g/m². The elastic fiber yarn used can be a spandex yarn or the like, and it is possible to use “ROICA” manufactured by Asahi Kasei Corp., or “LYCRA” manufactured by Toray Opelontex Co., Ltd., for example. The stress varies according to the type of the spandex fiber, and therefore, it is preferable to select a fiber appropriate for a region where the fiber is to be used. However, as the swimsuit is to be used in swimming pools, it is preferable to use a spandex fiber that has high durability against chlorine, for example, “ROICA SP”, “LYCRA-176B”, “LYCRA-176E”, “LYCRA-254B”, and “LYCRA-909B”.

The elongation percentage of the fabric measured in accordance with the method A of the JIS 1096 (2010) (cut strip method), (load: 17.7 N (1.8 kg), width: 5 cm) in both the length direction and the width direction is preferably 60% to 180%, more preferably 70% to 170%, and further preferably 80% to 160%. It is appreciated that if the fabric has stretchability within the above range, the fabric has appropriate elasticity, is easy to wear, and is suitable for sports clothing including swimsuits.

The following describes the present invention with reference to the drawings. In the drawings referred to below, the same reference numeral denotes same elements.

FIG. 1A is a plan view photograph (80× magnification) showing a fabric for a swimsuit according to an embodiment of the present invention, and FIG. 1B is a photograph (80× magnification) showing a cross section taken along the line I-I in FIG. 1A. This fabric 1 for a swimsuit includes recessed stripe portions 2 and protruding stripe portions 3 that are continuous in one direction and alternately arranged, and the entire fabric is formed by a herringbone structure. A pitch 4 between a protruding stripe portion 3a and an adjacent protruding stripe portion 3b shown in FIG. 1B is preferably 300 to 1500 μm, although the pitch may vary depending on the yarns used. A height difference between the recessed stripe portions 2 and the protruding stripe portions 3 is preferably 50 to 500 μm, although the height difference may vary depending on the yarns used.

FIG. 2 is a schematic diagram additionally showing the movement of a non-elastic yarn 6 in a plan view photograph (5× magnification) of a fabric for a swimsuit according to an embodiment of the present invention. Such a movement of the non-elastic yarn 6 can be realized in a half tricot warp knitted fabric. As shown in FIG. 2, recessed stripe portions and protruding stripe portions extend along the transverse direction when the knitted fabric is knitted, but a swimsuit is sewn such that the stripe portions extend along the height (length) direction.

FIG. 3 is a knitting diagram of a fabric for a swimsuit according to an embodiment of the present invention. The numerals 1 to 7 shown above indicate knitting needle numbers, and the example shown in FIG. 3 includes two courses a and b in which the upper direction of the non-elastic yarn 6 is the same. The reference numeral 7 denotes an elastic yarn.

FIG. 4 is a knitting diagram of a fabric for a swimsuit according to another embodiment of the present invention. Differently from FIG. 3, this knitting diagram includes three courses a, b, and c in which the upper direction of the non-elastic yarn 6 is the same. It is possible to form a herringbone structure with both of the knitting diagrams.

EXAMPLES

The following specifically describes the present invention using examples. Note that the present invention is not limited to the following examples.

Characteristic values in the examples were measured using the following methods.

<Pitch Between Adjacent Protruding Stripe Portions and Height Difference Between Recessed Stripe Portion and Protruding Stripe Portion>

The pitch and height difference between stripe portions of a fabric were measured using a one-shot 3D shape measurement device (VR-6000) manufactured by KEYENCE CORPORATION and an analysis the analysis software thereof. A photograph showing a surface of the fabric like that shown in FIG. 1A was captured with 80× magnification using VR-6000, shape correction was performed using the analysis the analysis software thereof, and thereafter a cross section of the fabric was observed from a horizontal direction with respect to a stripe pattern like that shown in FIG. 1B. At this time, values of the pitch and the height difference were each measured at 10 or more points based on the following definitions, and average values were calculated.

Pitch (Rib Interval) Between Adjacent Protruding Stripe Portions

An interval between a protruding stripe portion and an adjacent protruding stripe portion that are adjacent to a line orthogonal to the stripe portions is defined as the pitch (rib interval).

Height Difference Between Recessed Stripe Portion and Protruding Stripe Portion

A distance between the lowest point on a recessed portion and the highest point on a protruding portion that are adjacent to the line orthogonal to the stripe portions is defined as the height difference.

<Elongation Percentage>

The measurement was performed in accordance with the JIS L1096 (2010) A method and the cut strip method. The width of a test piece was set to 5 cm, and a holding distance was set to 20 cm. An initial load was set to a load corresponding to the gravitational force that acts on a length of 1 m with the width of the test piece. The tension rate was set to 20 cm/min. An elongation percentage (%) when a load of 17.7 N (1.8 kg) was applied was measured. The elongation percentage indicates stretchability.

<Surface Friction Resistance in Water>

FIG. 5 is a diagram schematically showing a device 10 for measuring the fluid resistance of a fabric for a swimsuit according to an embodiment of the present invention. This device 10 for measuring the fluid resistance includes a circulating water bath that is filled with water and in which water is caused to flow at a constant flow rate of 0.13 m/s. Arrows 11 show the water flow direction. A wing-shaped model 12 is fixed to a support arm extending downward from a force sensor 14 that is fixed to a support table, and the surface of the wing-shaped model 12 is covered with the fabric for the swimsuit in the circumferential direction. Thus, the drag shown by an arrow 13 is measured using the force sensor 14 to measure the surface friction resistance in water.

FIG. 6A is a schematic plan view of the wing-shaped model used in the device for measuring the fluid resistance, and FIG. 6B is a schematic side view of the wing-shaped model. The wing-shaped model is a wing-shaped model of aircrafts produced by National Advisory Committee for Aeronautics (NACA, currently known as NASA), and is registered as NACA0012. A thick front end portion of the wing shape is taken to be a head portion, and a method for putting on the fabric is determined such that the head portion is oriented toward the water flow direction. The model has a length of 150 mm, a wing width of 17.5 mm in a plan view, and a height of 100 mm in a side view.

A drag coefficient CD is calculated using the following mathematical formula. The drag coefficient CD does not have a unit.

C D = D 1 2 ⁢ ρ ⁢ u 2 ⁢ A [ Math 1. ]

wherein

• • D: drag (N)
  • ρ: fluid density (kg/m³)
  • u: model speed (m/s)
  • A: representative area (m²)

Example 1

1. Yarns Used

(1) Elastic Yarn

• • Polyurethane yarn (total fineness: 44 decitex, LYCRA® (trademark) 176E, hereinafter referred to as “44T-176E”)
  • Polyurethane yarn (total fineness: 55 decitex, LYCRA® (trademark) 254E, hereinafter referred to as “55T-254E”)

(2) Non-Elastic Yarn

Polyethylene terephthalate multifilament yarn (total fineness: 56 decitex, number of filaments: 36, TETORON® (TETRON is registered by Toray in the US) E62 manufactured by Toray Industries, Inc., hereinafter referred to as “56T-36-E62”)

2. Knitting of Knitted Fabric

A warp knitted fabric was knitted using a 32-gauge tricot warp knitting machine. At this time, a non-elastic yarn was supplied to a front reed, and an elastic yarn was supplied to a back reed. Thus, the herringbone stripe pattern including recessed stripe portions and protruding stripe portions shown in FIGS. 1 to 3 was formed with the non-elastic yarn.

3. Water-Repelling Processing

The gray knitted fabric was subjected to relaxing in a bath at a temperature of 80° C. to which a scouring agent was introduced, then dried, subjected to heat setting, dyed with a cationic dye in a bath at a temperature of 130° C., and then dried in accordance with a common dyeing process for a polyester two-way tricot knitted fabric.

Next, the fabric was immersed in a non-fluorine water-repelling processing liquid having the following prescription, squeezed with a mangle roller at a squeezing rate of 60%, dried at 130° C. for 2 minutes, and then subjected to final setting at 170° C. for curing.

[Prescription of Water-Repelling Processing Liquid]

• • “NEOSEED®” NR-158 (Hydrocarbon-based water repellent, manufactured by NICCA

CHEMICAL CO., LTD.): 5.0 mass %

• • “AMIDIR®” M-3 (Melamine-based crosslinking agent, manufactured by DIC Corporation): 0.3 mass %
  • “Catalyst ACX” (Organic catalyst, manufactured by DIC Corporation): 0.3 mass %
  • Isopropyl alcohol: 1.0 mass %
  • Water: 93.5 mass %

4. Sewing of Swimsuit

A competitive swimsuit for women shown in FIGS. 7 and 8 was sewn using the knitted fabric obtained as described above. The swimsuit was sewn such that the stripe pattern that was continuous in one direction of the fabric for the swimsuit extended in the height direction of the swimsuit. Also, the swimsuit was sewn into a pattern that was 30% smaller than a standard size of a human body. As shown in FIGS. 7 and 8, the swimsuit 20 was sewn such that a stripe pattern 21 including recessed stripe portions and protruding stripe portions formed by the herringbone structure extended in the height direction (length direction). A test for wearing the swimsuit was carried out, and it was confirmed that the swimsuit had a high elongation recovery rate, a low surface friction resistance in water, high stretchability, was easy to wear, was favorably held in intimate contact with the skin of the human body, and was suitable for competitive swimming.

Example 2

Example 2 was the same as Example 1, except that the gauge of the tricot warp knitting machine was changed to 36, and the non-elastic yarn was knitted as shown in FIG. 4.

Example 3

Example 3 was the same as Example 1, except that 55T-254E was used as the polyurethane elastic yarn, instead of 44T-176E.

Comparative Example 1

Comparative Example 1 was the same as Example 1, except that a knitted fabric described in Comparative Example 1 of JP 6012817B1 was used.

Comparative Example 2

Comparative Example 2 was the same as Example 1, except that a knitted fabric subjected to embossing processing and described in Example 1 of JP 6012817B1 was used.

Comparative Example 3

A polyurethane yarn (total fineness: 44 decitex, LYCRA® 176E manufactured by Toray Opelontex Co., Ltd., hereinafter referred to as “44T-176E”) was used as an elastic yarn, and a polyethylene terephthalate multifilament yarn (total fineness: 56 decitex, number of filaments: 24, TETORON® E62 manufactured by Toray Industries, Inc., hereinafter referred to as “56T-24-FS92”) was used as a non-elastic yarn. Here, the non-elastic yarn was supplied to the front reed and the middle reed, the elastic yarn was supplied to the back reed, the yarns were passed through all needles in the middle reed and the back reed, and the front reed was supplied with the yarn such that the yarn was passed through one needle and was not passed through two needles of every three needles. A tricot having a stripe structure including protruding portions and recessed portions, which did not have a herringbone pattern as shown in the structural diagram of FIG. 4, was knitted. Except for the above, Comparative Example 3 was the same as Example 1.

The conditions described above and results are collectively shown in Table 4.

	TABLE 4
	Ex. 1	Ex. 2	Ex. 3	Com. Ex. 1	Com. Ex. 2	Com. Ex. 3

Pattern	Herringbone	Herringbone	Herringbone	Plane	Emboss/plane	Knitted fabric
						including
						protrusions
						and recesses
Non-elastic yarn	56T-36-E62	56T-36-E62	56T-36-E62	56T-36-E62	56T-36-E62	56T-24-FS92
Elastic yarn	44T-176E	44T-176E	55T-254E	44T-176E	44T-176E	44T-176E
Knitting gauge number	32	36	36	32	32	32
Average pitch between	794	399	399	—	10154	13102
protruding portions (μm)
Average height difference	226	118	100	—	33	455
between protruding portion
and recessed portion (μm)
Elongation percentage
Length (%)	162	142	134	163	151	76
Width (%)	114	89	73	115	125	48
Elongation recovery rate
Length (%)	83.9	86.1	87.7	82.0	82.5	83.0
Width (%)	89.6	90.9	91.8	88.8	89.2	85.2
Knit density W (per inch)	76	74	73	78	78	52
C (per inch)	129	120	127	130	127	101
Basis weight (g/m2)	270	253	268	301	306	239
Thickness (mm)	0.68	0.59	0.55	0.60	0.52	0.78
Water flow resistance	0.0296	0.0292	0.0295	0.0320	0.0300	0.0332
value (Co value)

From the results shown in Table 4, it was confirmed that the fabrics of the swimsuits of Examples 1 to 3 had higher elongation recovery rates and lower surface friction resistances in water than the fabrics of Comparative Examples. The competitive swimsuit 20 shown in FIGS. 7 and 8 was sewn using these fabrics. The swimsuit 20 was sewn such that the stripe pattern 21 including recessed stripe portions and protruding stripe portions formed by the herringbone structure extended in the height direction (length direction). A test for wearing the swimsuit was carried out, and it was confirmed that the swimsuit had a high elongation recovery rate, a low surface friction resistance in water, high stretchability, was easy to wear, was favorably held in intimate contact with the skin of the human body, and was suitable for competitive swimming.

The invention may be embodied in other forms without departing from the spirit or essential characteristics thereof. The embodiments disclosed in this application are to be considered in all respects as illustrative and not limiting. The scope of the invention is indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.