CN114450443A

CN114450443A - Warp knit fabric and stretchable article

Info

Publication number: CN114450443A
Application number: CN202080065179.2A
Authority: CN
Inventors: 森下健一郎
Original assignee: 3M Innovative Properties Co
Current assignee: 3M Innovative Properties Co
Priority date: 2019-09-20
Filing date: 2020-08-20
Publication date: 2022-05-06
Also published as: BR112022005142A2; WO2021053431A1; JP2021050423A

Abstract

The present invention provides a warp knitted fabric, the warp knitted fabric according to an embodiment comprising: a plurality of warp yarns having stretchability and arranged in a weft direction; and a weft yarn having non-stretchability, wherein the weft yarn 3 is arranged to zigzag travel between the plurality of warp yarns, and the weft yarn forms a folded back portion with any one of the plurality of warp yarns and a loop folded back portion with a closed loop with any one of the plurality of warp yarns.

Description

Warp knit fabric and stretchable article

One aspect of the present disclosure relates to warp knit fabrics and stretchable articles.

Background

JP 2018-131718A discloses a warp knitted fabric comprising a first yarn, a second yarn and a third yarn. The first and second yarns are elastic yarns and the third yarn is an inelastic yarn. The swing width of the first yarn (the number of crossover yarns) is less than the swing width of the second yarn and the swing width of the third yarn. That is, the first yarn is an elastic yarn having a relatively small swing width, the second yarn is an elastic yarn having a relatively large swing width, and the third yarn is an inelastic yarn having a relatively large swing width. In this warp knitted fabric, by combining three types of yarns such as the first yarn, the second yarn, and the third yarn, stretchability in the warp direction is increased, stretchability in the weft direction is decreased, and curling is suppressed.

Disclosure of Invention

The warp knit fabrics used in stretchable articles are required to be thin and light in order to enhance breathability while enhancing stretchability in one direction. However, when the warp knitted fabric is thin and light by reducing the number of yarns to be used or by reducing the density of the yarns, it is presumed that crimping or yarn twisting or tearing occurs. Therefore, warp knitted fabrics are required to be thin and light while maintaining strength.

A warp knit fabric according to one aspect of the present disclosure includes: a plurality of warp yarns having stretchability and arranged in a weft direction; and a weft yarn having non-stretchability, wherein the weft yarn forms a folded back portion with respect to a warp yarn of the plurality of warp yarns positioned on each of two end sides in the weft direction, and the weft yarn forms a closed loop with a warp yarn of the plurality of warp yarns positioned on a center side in the weft direction.

Since the warp knitted fabric includes the weft yarn having non-stretchability and the plurality of warp yarns having stretchability, high stretchability in the warp direction can be achieved, and the warp knitted fabric is thin and light by combining the two types of yarns and setting the number of knitting patterns of the yarns to two. In the present disclosure, "type of yarn" indicates the type of yarn thickness, yarn material, etc., and "pattern" indicates the type of yarn knitting pattern. Even when a plurality of "patterns" are identical to each other, the "types of yarns" used as the patterns may be different from each other. In the warp knitted fabric described above, the weft yarn forms a folded back portion with the warp yarn positioned on both end sides in the weft direction among the plurality of warp yarns, and forms a closed loop with the warp yarn positioned on the center side in the weft direction. In the present disclosure, "folded back" indicates a pattern in which one of two yarns is folded back towards the other yarn and away from the other yarn. "closed loop" indicates a pattern in which the yarns form loops of 360 ° (one turn) or more. As described above, the non-stretchable weft yarn forms the folded back portion with the warp yarns on both end sides in the weft direction and forms the closed loop with the warp yarn on the center side in the weft direction, whereby the strength of the warp knitted fabric can be increased by both types of yarns. Further, by forming two patterns of the folded back portion and the closed loop by a plurality of warp yarns and weft yarns, the warp knitted fabric can be made thin and light while increasing strength.

The weft yarns may span at least three warp yarns.

The weft yarn may form an acyclic folded back portion that is folded back with respect to the warp yarn positioned on each of the two end sides in the weft direction among the plurality of warp yarns without forming a loop.

A warp knit fabric according to another aspect of the present disclosure includes: a plurality of warp yarns having stretchability and arranged in a weft direction; and a weft yarn having non-stretchability, wherein the weft yarn is arranged to zigzag travel between the plurality of warp yarns, and the weft yarn forms a folded back portion with any one of the plurality of warp yarns and forms a closed loop with any one of the plurality of warp yarns.

In the warp knitted fabric, the weft yarn forms a folded back portion with respect to any one of the plurality of warp yarns and forms a closed loop with any one of the plurality of warp yarns. Thus, for each of the plurality of warp yarns, the weft yarns form both the folded back and the closed loops, thereby increasing the strength of the warp knitted fabric by both types of yarns. In this warp knitted fabric, as described above, since the weft yarn has non-stretchability and the plurality of warp yarns have stretchability, the warp knitted fabric can be made thin and light by two patterns formed of two types of yarns, and high stretchability in the warp direction can be achieved.

The closed loop and the folded back portion may be provided alternately.

The weft yarn may span two warp yarns and the weft yarn may form a folded back portion with respect to one of the two warp yarns and form a closed loop with the other of the two warp yarns.

The stretchable article according to one aspect of the present disclosure is a stretchable article comprising the above warp knitted fabric and constituting any one of a hygiene article, a medical article, a sporting good, an underwear, and a bedding article. Since the stretchable article includes the above warp-knitted fabric, the stretchable article exhibits the same effect as the above warp-knitted fabric.

According to an aspect of the present disclosure, thickness and weight may be reduced while maintaining strength.

Drawings

Fig. 1 is a view illustrating a warp knitted fabric according to an embodiment.

Fig. 2 is a view showing an example of stretching the warp knitted fabric of fig. 1 in a warp direction.

FIG. 3 is a diagram illustrating an exemplary knitting structure of the warp and weft yarns of the warp knit fabric of FIG. 1.

Fig. 4 is a schematic enlarged view of a closed loop of weft yarns in the knitted structure of fig. 3.

FIG. 5 is a schematic enlarged view of another closed loop of weft yarns in the knit structure of FIG. 3.

Fig. 6 is a diagram showing a knitting structure of warp and weft yarns of a warp knitted fabric according to a modified example.

Fig. 7 is a diagram showing a knitting structure of warp and weft yarns of a warp knitted fabric according to another modified example.

Fig. 8 is a diagram showing a knitting structure of warp and weft yarns of a warp knitted fabric according to still another modified example.

Fig. 9 is a diagram showing a knitting structure of warp and weft of a warp knitted fabric according to one comparative embodiment.

Fig. 10 is a diagram showing a knitting structure of warp and weft of a warp knitted fabric according to another comparative example.

Fig. 11 is a diagram showing a knitting structure of warp and weft yarns of a warp knitted fabric according to still another comparative embodiment.

Fig. 12 is a graph showing the results of a tensile test performed on the warp knitted fabrics according to the embodiment and the comparative embodiment.

Detailed Description

Hereinafter, embodiments of the warp knitted fabric and the stretchable article according to the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted as appropriate. For ease of understanding, the drawings may be partially simplified or enlarged, and the size ratio and the like are not limited to those shown in the drawings.

Fig. 1 and 2 are views schematically showing a warp knitted fabric 1 according to an embodiment. As shown in fig. 1 and 2, the warp knitted fabric 1 is a stretchable warp knitted fabric extending in the warp direction D1 and the weft direction D2 and having high stretchability in the warp direction D1. The warp direction D1 is, for example, the Machine Direction (MD) of the fed warp knitted fabric 1, and the weft direction D2 is the Cross Direction (CD) orthogonal to the MD.

The warp knitted fabric 1 is, for example, a stretchable warp knitted fabric which is hardly stretched in the weft direction D2 but is stretched in the warp direction D1 orthogonal to the weft direction D2. The density of the warp knitted fabric 1 in the warp direction D1 is, for example, 15 yarns/inch or more and 25 yarns/inch or less, and is, for example, 20 yarns/inch. The weight per unit area of the warp knitted fabric 1 is, for example, 25gsm or more and 32gsm or less, and is, for example, 26 gsm. The air permeability of the warp knitted fabric 1 is, for example, 195 (cm)³/cm²S) or greater and 800 (cm)³/cm²S) or less, and may be, for example, 200 (cm)³/cm²·s)。

The warp knitted fabric 1 is, for example, a fabric included in a stretchable article: the stretchable article comprises any one of: absorbent articles such as diapers, sanitary napkins or incontinence pads; hygiene articles, including hygiene materials, such as hemostatic tapes; a medical article; sporting goods; an undergarment; and bedding articles. As a specific example, the warp knit fabric 1 may be used as an elastomeric core layer in the waist or leg portions of a diaper. The warp knitted fabric 1 may be used for any one of tights for women, tight dresses, foot protectors, hosiery, underwear, sportswear, sports underwear, and swimsuits.

A warp knit fabric comprising: a plurality of folded back portions formed of a plurality of yarns; and a plurality of rings, including open and closed rings. "folded back" indicates a portion in which one of the two yarns is folded back toward the other yarn and away from the other yarn. "loop" indicates a looped portion formed by a yarn, "closed loop" indicates a loop in which the yarn is looped one or more times, and "open loop" indicates a loop in which the yarn is not looped (e.g., a portion in which the yarn is U-shaped). The "non-loop folded back" described later indicates a folded back where no loop is formed. The "folded back portion" includes a non-loop folded back portion and a folded back portion forming a loop (hereinafter sometimes referred to as a loop folded back portion).

Fig. 3 is a diagram showing a knitting structure of the warp knitted fabric 1. As shown in fig. 3, for example, the warp knitted fabric 1 includes warp yarns 2 as stretchable front yarns and weft yarns 3 as non-stretchable back yarns, and is formed of two types of yarns. Warp yarn 2 is an elastic yarn and weft yarn 3 is a non-elastic yarn. For example, the oscillation width of the warp yarn 2 is smaller than that of the weft yarn 3. Thus, high stretchability in warp direction D1 is exhibited by warp yarn 2, and high stretchability in warp direction D1 is achieved.

The thickness (weight per unit) of the warp yarn 2 is, for example, 44T (dtex) or 22T. Warp yarn 2 is arranged in the weft direction D2. Warp yarn 2 comprises, for example, open loops 2b and closed loops 2c, and open loops 2b and closed loops 2c are arranged alternately in warp direction D1. The thickness (weight per unit) of the weft yarn 3 is, for example, 22T. The weft yarns 3 are arranged so as to meander between the plurality of warp yarns 2 and to bridge the plurality of warp yarns 2. As an example, weft yarn 3 forms a

closed loop

10, 20 with open loop 2b of warp yarn 2 and a folded back 30 with respect to closed loop 2c of warp yarn 2.

The material of the warp yarns 2 is for example polyurethane. However, the material of the warp yarn 2 may be polyether ester and may be appropriately changed. The material of the weft yarns 3 includes, for example, at least one of polyethylene terephthalate, nylon, polypropylene, polyester, polyolefin, polyamide, acrylic, cellulose, wool, and linen. The knitting structure of warp yarn 2 is, for example, 0-1/1-0/1-0/0-1, and the knitting structure of weft yarn 3 is 3-2/5-5/2-3/0-0.

The warp knitted fabric 1 includes, for example, a plurality of

closed loops

10, 20 and a plurality of folded back portions 30. The weft yarns 3 form alternately, for example, closed

loops

10, 20 and a folded back portion 30. As a specific example, the weft yarns 3 may form a closed loop 10, a folded back portion 30, a closed loop 20 and a folded back portion 30 in this order. The folded back portion 30 is formed with respect to the warp yarn 2 positioned on each of the two end sides in the weft direction D2 among the plurality of warp yarns 2. The folded back portion 30 is, for example, a non-loop folded back portion. That is, at the folded back portion 30, the weft yarn 3 is folded around the warp yarn 2 without forming an annular portion.

Weft yarn 3 forms a

closed loop

10, 20 with warp yarn 2 of the plurality of warp yarns 2 positioned on the center side in the weft direction D2. By way of example, weft yarn 3 spans three warp yarns 2. In this case, the weft yarn 3 forms the folded back portion 30 with respect to each of the two warp yarns 2 positioned at both ends in the weft direction D2, and forms the

closed loops

10, 20 with respect to the one warp yarn 2 positioned at the center in the weft direction D2.

Fig. 4 is an enlarged view of open loop 2b of warp yarn 2 and closed loop 10 of weft yarn 3. As shown in fig. 4, closed loop 10 is formed by weft yarn 3 wrapped around open loop 2b of warp yarn 2. By way of example, closed loop 10 is formed by weft yarn 3 extending in oblique direction D3 with respect to warp yarn 2, passing under warp yarn 2 to reach open loop 2b of warp yarn 2, passing over warp yarn 2 while circulating in one direction (e.g., clockwise), and exiting in oblique direction D3.

Fig. 5 is an enlarged view of open loop 2b of warp yarn 2 and closed loop 20 of weft yarn 3. As shown in FIG. 5, closed loop 20 opposes closed loop 10 in weft direction D2. As an example, closed loop 20 is formed by weft yarn 3 extending in oblique direction D4 with respect to warp yarn 2, passing under warp yarn 2 to reach open loop 2b of warp yarn 2, passing over warp yarn 2 while circulating in a direction opposite to the above-mentioned one direction (e.g., counterclockwise), and coming out in oblique direction D4. The tilt direction D4 is a direction intersecting the tilt direction D3, and is orthogonal to the tilt direction D3, for example.

The knitting structure of the warp knitted fabric 1A according to the modified example will be described with reference to fig. 6. Since a part of the warp knitted fabric according to the following modified example overlaps with a part of the warp knitted fabric 1 described above, a description of the overlapping with the warp knitted fabric 1 is appropriately omitted. As shown in fig. 6, the warp knitted fabric 1A includes a plurality of warp yarns 2 and weft yarns 3, and the arrangement of the plurality of warp yarns 2 is the same as that of the warp knitted fabric 1 described above. Further, the orientation of weft yarn 3 in warp knitted fabric 1A is an opposite orientation to the orientation of weft yarn 3 in warp knitted fabric 1. In warp knitted fabric 1A, the knitting structure of warp yarn 2 is 0-1/1-0/1-0/0-1, and the knitting structure of weft yarn 3 is 2-3/0-0/3-2/5-5.

Next, the effects of the warp knitted

fabrics

1, 1A described above will be described.

Since the warp knitted

fabric

1, 1A includes the weft yarn 3 having non-stretchability and the plurality of warp yarns 2 having stretchability, high stretchability in the warp direction D1 can be achieved, and the warp knitted

fabric

1, 1A is made thin and light by setting the number of knitting patterns of the yarns to two. From the viewpoint of reducing the thickness and weight of the warp knitted fabric, it is not desirable in some cases that the number of knitting patterns is three or more. However, in the warp knitted

fabrics

1, 1A, the number of patterns is two, which can make the warp knitted

fabrics

1, 1A light and thin. That is, the weft yarn 3 forms the folded rear portion 30 with respect to the warp yarns 2 positioned on both end sides in the weft direction D2 among the plurality of warp yarns 2, and forms the

closed loops

10, 20 with the warp yarn 2 positioned on the center side in the weft direction D2. As described above, the non-stretchable weft yarn 3 forms the folded rear portion 30 with respect to the warp yarns 2 at both ends in the weft direction D2, and forms the

closed loops

10, 20 with the warp yarns 2 at the center side in the weft direction D2, whereby the strength of the warp knitted

fabric

1, 1A can be increased by both types of yarns. Further, by forming two patterns of the folded back portion 30 and the

closed loops

10, 20 by the plurality of warp yarns 2 and weft yarns 3, the warp knitted

fabrics

1, 1A can be made thin and light while increasing strength. In the stretchable article comprising the warp knitted

fabric

1, 1A, the same effect as described above can be obtained.

Weft yarn 3 may span at least three warp yarns 2. In this case, since weft yarn 3 bridges three or more warp yarns 2 in weft direction D2, the strength of warp knitted

fabric

1, 1A in warp direction D1 can be increased.

The weft yarn 3 may form an acyclic folded back portion (folded back portion 30) which is folded back without forming a loop with respect to the warp yarn 2 positioned on each of the two end sides in the weft direction D2 among the plurality of warp yarns 2. Here, "the warp yarn 2 of the plurality of warp yarns 2 positioned on each of the two end sides in the weft direction D2" indicates the warp yarn 2 positioned on both ends in the weft direction D2 of the plurality of warp yarns 2 bridged by the weft yarn 3. In this case, since weft yarn 3 does not form a loop at folded back portion 30, the stretchability of warp knitted

fabric

1, 1A in warp direction D1 can be enhanced.

The

closed loops

10, 20 and the folded back portion 30 may be provided alternately. In this case, the strength and stretchability in the warp direction D1 of the warp knitted

fabric

1, 1A can be improved, and the configuration of the warp knitted

fabric

1, 1A can be simplified.

Next, a knitting structure of the warp knitted fabric 1B according to another modified example will be described with reference to fig. 7. As shown in fig. 7, in the warp knitted fabric 1B, the weft yarn 3 forms a loop folded back portion 40 which is folded back by forming a loop with respect to the closed loop 2c of the warp yarn 2. In the loop-folded back portion 40, for example, a closed loop is formed by the weft yarn 3. In warp knitted fabric 1B, the knitting structure of warp yarn 2 is, for example, 0-1/1-0/1-0/0-1, and the knitting structure of weft yarn 3 is 3-2/5-4/2-3/0-1.

The loop-folded back portion 40 of the weft yarn 3 is formed with respect to the closed loop 2c of the warp yarn 2 positioned on each of the two end sides in the weft direction D2 among the plurality of warp yarns 2. As an example, weft yarn 3 forms loop-folded back 40 with respect to each of the two yarns 2 positioned at both ends in weft direction D2. The warp knitted fabric 1 includes a plurality of

closed loops

10, 20 and a plurality of loop folded back portions 40. The weft yarns 3 form, for example, a closed loop 10, a loop folded back 40, a closed loop 20 and a loop folded back 40 in this order.

As described above, in the warp knitted fabric 1B, since the weft yarns 3 form the loop-folded back portions 40 with respect to the warp yarns 2 positioned at both ends in the weft direction D2, the warp knitted fabric 1B can be made thin and light, and the strength of the warp knitted fabric 1B can be further increased while maintaining stretchability in the warp direction D1.

A warp knitted fabric 1C according to still another modified example will be described with reference to fig. 8. As shown in fig. 8, weft yarn 3 spans two warp yarns 2. Weft yarn 3 forms a loop-folded back portion 40 with respect to open loop 2b of warp yarn 2 and forms a folded back portion 30 with respect to closed loop 2c of warp yarn 2. For example, the loop folded back 40 is a closed loop and the folded back 30 is a non-loop folded back.

As described above, the warp knitted fabric 1C includes the plurality of folded back portions 30 and the plurality of loop folded back portions 40. For example, weft yarn 3 alternately forms folded back portion 30 and loop folded back portion 40. The weft yarn 3 forms the folded back portion 30 for one of the two warp yarns 2, and forms the ring folded back portion 40 for the other of the two warp yarns 2. In warp knitted fabric 1C, for example, the knitting structure of warp yarn 2 is 0-1/1-0/1-0/0-1, and the knitting structure of weft yarn 3 is 2-3/5-5.

In the warp knitted fabric 1C, the weft yarn 3 may form the folded back portion 30 with any one of the plurality of warp yarns 2, and may form the loop folded back portion 40 of the closed loop with any one of the plurality of warp yarns 2. That is, as shown in fig. 8, weft yarn 3 may form the folded back portion 30 in one warp yarn 2 and weft yarn 3 may form the loop folded back portion 40 in the other warp yarn 2, or weft yarn 3 may form both the folded back portion 30 and the loop folded back portion 40 in one warp yarn 2. As described above, since the plurality of warp yarns 2 and the plurality of weft yarns 3 form both the folded back portion 30 and the closed loop, the strength of the warp knitted fabric 1C can be increased by both types of yarns. As described above, since the weft yarns 3 are non-stretchable and the plurality of warp yarns 2 are stretchable, the warp knitted fabric 1C can be made thin and light by the two types of yarns and high stretchability in the warp direction can be achieved.

A closed loop (loop folded back 40) and folded back 30 may be provided alternately. In this case, an increase in strength and an increase in stretchability in the warp direction D1 of the warp knitted fabric 1 can be achieved, and the configuration of the warp knitted fabric 1C can be simplified.

Further, as in warp knitted fabric 1C, weft yarn 3 may bridge over two warp yarns 2, and weft yarn 3 may form folded back 30 with respect to one of the two warp yarns 2 and a closed loop with respect to the other of the two warp yarns 2. In this case, the strength of the warp knitted fabric 1C can be maintained, and the configuration of the warp knitted fabric 1C can be further simplified.

Embodiments and modified examples of warp knit fabrics and stretchable articles according to the present disclosure have been described above. However, the present invention is not limited to the above-described embodiment and modified examples. Various modifications may be made to the invention without departing from the spirit thereof as set forth in the claims. For example, the shape, thickness, material, number and arrangement of the yarns constituting the warp knitted fabric may be appropriately changed within the scope of the above-described gist.

(examples)

Next, an example of the warp knitted fabric will be described. The present invention is not limited to the following examples. In the experiment according to the examples, the warp knitted fabrics of examples 1 to 4 and comparative examples 1 to 3, which are described later, were subjected to a tensile test, and tensile stress and elongation were measured. In the tensile test, the tensile stress at 200% elongation of the warp knitted fabrics was measured according to JIS K7127, and each warp knitted fabric was pulled in the warp direction (MD) at a test piece width of 25mm, a chuck interval of 25mm, and a test speed of 300 mm/min.

Example 1

The warp knitted fabric according to example 1 has a knitting structure similar to the warp knitted fabric 1 shown in fig. 3, the material of the warp yarn 2 having stretchability is polyurethane, and the thickness of the warp yarn 2 is 44T. The material of weft yarn 3 with non-stretchability is polyethylene terephthalate and the thickness of weft yarn 3 is 22T. The knitting structure of warp yarn 2 is 0-1/1-0/1-0/0-1, and the knitting structure of weft yarn 3 is 3-2/5-5/2-3/0-0. In each of the subsequent examples 2 to 4 and comparative examples 1, 2, the material and thickness of the warp yarn 2 and the material and thickness of the weft yarn 3 were the same as those in example 1.

Example 2

The warp knitted fabric according to example 2 has the same knitting structure as the warp knitted fabric 1A shown in fig. 6, and the knitting structure of the warp yarn 2 is 0-1/1-0/1-0/0-1, and the knitting structure of the weft yarn 3 is 2-3/0-0/3-2/5-5.

Example 3

The warp knitted fabric according to example 3 has the same knitting structure as the warp knitted fabric 1B shown in fig. 7, and the knitting structure of the warp yarn 2 is 0-1/1-0/1-0/0-1 and the knitting structure of the weft yarn 3 is 3-2/5-4/2-3/0-1.

Example 4

The warp knitted fabric according to example 4 has the same knitting structure as the warp knitted fabric 1C shown in fig. 8, and the knitting structure of the warp yarn 2 is 1-0/0-1, and the knitting structure of the weft yarn 3 is 3-3/1-0.

Comparative example 1

In the warp knitted fabric according to comparative example 1, as shown in fig. 9, the weft yarn 3 bridges two warp yarns 2. Weft yarn 3 has only a closed loop folded back 40 and no non-loop folded back. The knitting structure of warp yarn 2 is 0-1/1-0 and the knitting structure of weft yarn 3 is 1-0/2-3.

Comparative example 2

In the warp knitted fabric according to comparative example 2, as shown in fig. 10, the weft yarn 3 bridges two warp yarns 2. The weft yarns 3 have only folded back portions 30 which are non-loop folded back portions and do not have a closed loop. The knitting structure of warp yarn 2 is 1-0/1-0 and the knitting structure of weft yarn 3 is 0-0/3-3.

Comparative example 3

As shown in fig. 11, the warp knitted fabric according to comparative example 3 includes three types of yarns, i.e., a warp yarn 2, a weft yarn 3, and a second weft yarn 103. In fig. 11, the proportion of the warp knitted fabric in the weft direction is different from those in fig. 3 or fig. 6 to 10. The material of the warp yarns 2 is polyurethane, the material of the weft yarns 3 is polyethylene terephthalate, and the material of the second weft yarns 103 is polyurethane. The knitting structure of warp yarn 2 is 0-1/1-0, the knitting structure of weft yarn 3 is 0-1/3-2, and the knitting structure of second weft yarn 103 is 0-0/3-3.

Fig. 12 shows the results of the tensile test performed on examples 1 to 4 and comparative examples 1 to 3. Fig. 12 is a graph showing the relationship between the elongation and the tensile strength of each of examples 1 to 4 and comparative examples 1 to 3. As shown in fig. 12, it was found that the warp knitted fabric according to comparative example 3 could not be elongated in the MD (warp direction D1) under the same tensile stress (no faradaic elongation unless the tensile stress became large) as compared with other warp knitted fabrics. In contrast, it was found that each of the warp knitted fabrics of examples 1 to 4 and comparative examples 1, 2 can be elongated by tension in the MD under a small tensile stress.

In the warp knitted fabric of comparative example 1 in which the weft yarn 3 bridging two warp yarns 2 does not have an acyclic fold back, the warp knitted fabric can be elongated by tension under a small tensile stress, but uneven stretching and yarn twisting occur during the stretching. In addition, in the warp knitted fabric of comparative example 2 in which the weft yarn 3 bridging two warp yarns 2 does not have a closed loop, tearing in MD occurs during stretching.

In another aspect, in each of the following warp knit fabrics: examples 1 and 2 in which weft yarn 3 bridging three warp yarns 2 has a non-loop folded back and closed loops; example 3 in which weft yarn 3 bridging three warp yarns 2 has a closed loop; and example 4, in which weft yarn 3 bridging two warp yarns 2 has a non-loop-folded back and closed loops, no uneven stretching, yarn twisting and tearing occur. Further, it was found that in the warp knitted fabrics of examples 1 to 4, abnormalities such as uneven stretching which may occur upon stretching can be suppressed, and the warp knitted fabric can be elongated in the MD under a small tensile stress. Furthermore, the following results were obtained: the warp knitted fabric of example 4 was curled (bent), and the warp knitted fabric of example 3 was slightly curled, but the warp knitted fabrics of examples 1 and 2 were rarely curled.

List of reference marks

1. 1A, 1B, 1C: warp knitted fabric, 2: warp, 2 b: open loop, 2 c: closed loop, 3: weft, 10, 20: closed loop, 30: folded back, 40: loop-folded back (closed loop), D1: warp direction, D2: weft, D3, D4: direction of inclination

Claims

1. A warp knit fabric comprising:

a plurality of warp yarns having stretchability and arranged in a weft direction; and

weft yarns having non-stretchability, wherein

The weft yarn forms a folded back portion with respect to the warp yarns positioned on each of two end sides in the weft direction among the plurality of warp yarns, and

the weft yarns form closed loops with the warp yarns of the plurality of warp yarns positioned on a central side in the weft direction.

2. The warp knit fabric according to claim 1, wherein

The weft yarns span at least three of the warp yarns.

3. The warp knitted fabric according to claim 1 or 2, wherein

The weft yarn forms an acyclic folded back portion that is folded back with respect to the warp yarns of the plurality of warp yarns positioned on each of two end sides in the weft direction without forming a loop.

4. A warp knit fabric comprising:

weft yarns having non-stretchability, wherein

The weft yarns are arranged to meander between the plurality of warp yarns, and

the weft yarn forms a folded back portion with any one of the plurality of warp yarns and forms a closed loop with any one of the plurality of warp yarns.

5. The warp knit fabric according to claim 4, wherein

Alternately providing the closed loop and the folded back portion.

6. The warp knitted fabric according to claim 4 or 5, wherein

The weft yarn bridges two of the warp yarns, and

the weft yarns form the folded back portion with respect to one of the two of the warp yarns and the closed loop with respect to the other of the two of the warp yarns.

7. A stretchable article comprising the warp knit fabric according to any one of claims 1 to 6, wherein

The stretchable article constitutes any of a hygiene article, a medical article, a sporting good, an undergarment, and a bedding product.