Knitted fabric

Abstract

The purpose of the present invention is to provide a knitted fabric that, while maintaining a good tactile sensation, exhibits an excellent processability and is provided with firmness.　The knitted fabric is provided with a three-dimensional structure composed of an upper layer, a lower layer, and a connection section that connects the upper layer and the lower layer. A portion or all of at least one of the upper layer and lower layer comprises a heat-shrinkable yarn that has a shrinkage ratio of at least 20% at 180°C for 15 minutes. At least one of the upper layer and lower layer contains fiber that is thicker than fiber that mainly constitutes a base structure.

Description

Technical Field

[0001] The present invention particularly relates to a knitted fabric suitable for shoes.

Background Art

[0002] Conventionally, a knitted fabric having a three-dimensional structure composed of an upper layer, a lower layer, and a connecting portion connecting these upper and lower layers has been known (see, for example, Patent Document 1). This knitted fabric has a base portion and a plurality of convex stripe portions formed parallel to each other along the knitting direction on this base portion. The convex stripe portion consists of a top portion formed of a knitting row extending along the knitting direction, and a knitting row extending along the knitting direction, with the base portion side being knitted into the base and the top portion side being locked to the top, and is knitted so as to connect the base and the top. It consists of two side wall portions. Among the top portion and the two side wall portions, at least one part has a color different from other parts.

[0003] In such a knitted fabric, by arranging a color different from other parts for at least one part among the top portion and the two side wall portions constituting the convex stripe portion, when an observer views the knitted fabric from a direction intersecting the knitting direction, a color effect is exhibited in which the color visually recognized changes according to the position.

[0004] Also, in such a knitted fabric, a mesh portion can be formed by stretching the connecting yarn between a part of the top portion of each convex stripe portion and a part of the top portion of another convex stripe portion adjacent to this convex stripe portion. In this type of knitted fabric, since the convex stripe portions are connected to other adjacent convex stripe portions and the mesh portion, the shape stability of the convex stripe portion can be further enhanced. Further, since the convex stripe portion is visually recognized through the opening portion of the mesh portion when the mesh portion is formed, a more complex pattern can be expressed compared to the case where there is no mesh portion.

[0005] And such a knitted fabric is said to be suitably applicable to highly fashionable clothes, bags, hats, shoes, etc.

[0006] On the other hand, there is research into three-dimensional knitted fabrics that possess excellent cushioning and compression recovery, heat retention, breathability, and shape retention, have great resistance to deformation under repeated loading, and are aesthetically pleasing, making them suitable for use as upper materials, insoles, etc., for shoes and the like. For example, a three-dimensional knitted fabric has been disclosed that is composed of knitted fabrics on the front and back surfaces made of a weft knit structure, and yarns that join the knitted fabrics on both the front and back surfaces, and the yarns that join the knitted fabrics on both the front and back surfaces contain elastic yarn (see, for example, Patent Document 2).

[0007] Furthermore, a warp-knitted fabric is disclosed that has firmness and excellent shape retention, and is particularly suitable as an interlining for the stand-up collar of school uniforms, etc., and is knitted using a warp-knit structure consisting of a face knit fabric, a purl knit fabric, and a connecting yarn that integrates the face knit fabric and the purl knit fabric, wherein part or all of the connecting yarn is a thermoplastic yarn, and the connecting yarn is inserted into the sinker loops of the face knit stitches that constitute the face knit fabric and the sinker loops of the purl knit stitches that constitute the purl knit fabric, respectively (see, for example, Patent Document 3). [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2017-14676 [Patent Document 2] Japanese Patent Publication No. 2001-164444 [Patent Document 3] Japanese Patent Publication No. 2019-11546 [Overview of the project] [Problems that the invention aims to solve]

[0009] Incidentally, although the knitted fabric described in Patent Document 1 is excellent in terms of aesthetics and fashion, when applied to shoes, for example, if the knitted fabric is cut into several parts and then the parts are subdivided to form complex shapes, the process becomes complicated, and it takes a long time to complete the shoes from the knitted fabric, resulting in processing challenges such as increased manufacturing costs.

[0010] Furthermore, for use in the upper material of shoes and other outer coverings, a certain firmness and resilience are necessary, and this also needs improvement.

[0011] While a knitted fabric for shoes is described in Patent Document 2, it offers excellent flexibility and cushioning, but still lacks firmness and resilience. Furthermore, it is necessary to sew reinforcing materials into the toe and heel areas as needed, requiring cutting and sewing processes for the parts, as mentioned above, resulting in increased manufacturing costs and other processing challenges.

[0012] Furthermore, the knitted fabric described in Patent Document 3 achieves a certain degree of improvement in firmness and resilience by using a core-sheath composite yarn in which the sheath portion is made of a low-melting-point polymer and the core portion is made of a high-melting-point polymer in the connecting yarn that integrates the front knit and back knit fabrics. However, while it is suitable for thin fabrics such as interlinings, improvements in cushioning and feel are necessary for application to shoe upper materials, etc. Also, as mentioned above, the problem of processability has not been solved.

[0013] Thus, especially for shoe applications, there is a demand for knitted fabrics that possess firmness, resilience, and a pleasant feel against the skin, while also being highly workable. However, all of the aforementioned knitted fabrics still had room for further improvement.

[0014] This invention has been made in view of the above circumstances, and aims to provide a knitted fabric that maintains a good feel against the skin, has excellent processability, and possesses firmness and resilience. [Means for solving the problem]

[0015] To solve these problems, the present invention consists of one of the following configurations. (1) A knitted fabric having a three-dimensional structure comprising an upper layer, a lower layer, and a connecting portion connecting the upper and lower layers, wherein at least one of the upper or lower layers contains a heat-shrinkable yarn having a shrinkage rate of 20% or more at 180°C for 15 minutes, and at least one of the upper or lower layers contains fibers thicker than the fibers that mainly constitute the base fabric. (2) The knitted fabric described in (1), wherein at least one of the upper or lower layers has multiple openings. (3) The knitted fabric according to (1) or (2), wherein at least one of the upper or lower layers includes in part a structure different from the ground fabric. (4) A knitted fabric as described in any of (1) to (3), with a thickness of 2 to 15 mm. (5) The knitted fabric according to any one of (1) to (4), wherein the connecting portion is composed of multifilament in at least a part thereof. (6) The knitted fabric according to any one of (1) to (5), wherein at least one of the upper and lower layers is made of fused yarn in part or in whole. (7) The knitted fabric according to (6), wherein at least a portion of the fused yarn is an elastomer elastic yarn. (8) The knitted fabric according to (7), wherein the elastic yarn is a monofilament. (9) The knitted fabric according to (7) or (8), wherein the elastic yarn is a core-sheath composite monofilament consisting of a core component and a sheath component. (10) The knitted fabric according to (9), wherein the sheath component of the elastic yarn has a melting point at least 10°C lower than the melting point of the core component. (11) The knitted fabric according to (9) or (10), wherein the sheath component of the elastic yarn is a polyester elastomer. (12) The knitted fabric according to any one of (9) to (11), wherein the core component of the elastic yarn is a polyester elastomer. (13) A knitted fabric according to any of (1) to (12), wherein the heat shrinkage rate of at least one side is 10 to 60%. (14) A warp-knitted fabric as described in any of (1) to (13). [Effects of the Invention]

[0016] According to the knitted fabric of the present invention, when manufacturing a fiber product using this, the knitted fabric is cut into the minimum necessary number of parts, then sewn together, and finally heat-set to form a desired shape. Therefore, the manufacturing process can be simplified, and a fiber product can be manufactured in a short time, resulting in a knitted fabric with excellent processability. Also, while maintaining a good touch feeling, it contains thick fibers, so it has a firm and resilient feeling.

Brief Description of the Drawings

[0017] [Figure 1A] It is an explanatory drawing showing three-dimensionally the structure of a warp knitted fabric according to an embodiment of the present invention. [Figure 1B] It is an explanatory drawing showing three-dimensionally the structure of a warp knitted fabric according to this embodiment. [Figure 1C] It is an explanatory drawing showing three-dimensionally the structure of a warp knitted fabric according to this embodiment. [Figure 1D] It is an explanatory drawing showing three-dimensionally the structure of a warp knitted fabric according to this embodiment. [Figure 1E] It is an explanatory drawing showing three-dimensionally the structure of a warp knitted fabric according to this embodiment. [Figure 2] It is a structure diagram of a warp knitted fabric according to Example 1. [Figure 3] It is a structure diagram of a warp knitted fabric according to Example 2. [Figure 4] It is a structure diagram of a warp knitted fabric according to Example 3. [Figure 5] It is a structure diagram of a warp knitted fabric according to Example 4. [Figure 6] It is a structure diagram of a warp knitted fabric according to Comparative Example 1. [Figure 7] It is a structure diagram of a warp knitted fabric according to Comparative Example 2. [Figure 8] It is a structure diagram of a warp knitted fabric according to Comparative Example 3.

Modes for Carrying Out the Invention

[0018] The present invention relates to a knitted fabric having a three-dimensional structure composed of an upper layer, a lower layer, and a connecting portion that connects the upper and lower layers, wherein at least one of the upper or lower layers contains a heat-shrinkable yarn having a shrinkage rate of 20% or more at 180°C for 15 minutes, in part or in whole. In this invention, the terms "upper layer" and "lower layer" are merely convenient terms for either one of the layers, and the upper layer is not necessarily located above, nor is the lower layer necessarily located below.

[0019] In this invention, the heat-shrinkable yarn preferably contains fibers with excellent heat shrinkability, such as polyethylene terephthalate resin fibers. Such heat shrinkability is not limited to polyethylene terephthalate resin, which is a condensation polymer of terephthalic acid and ethylene glycol; it may also be found in polyethylene terephthalate resins in which a portion of the terephthalic acid is replaced with another dicarboxylic acid, or in polyethylene terephthalate resins in which a portion of the ethylene glycol is replaced with another diol.

[0020] In particular, in order to facilitate the development of excellent heat shrinkability in the heat-shrinkable yarn, it is preferable that the polyethylene terephthalate resin forming the heat-shrinkable yarn is a polyethylene terephthalate resin in which a portion of the terephthalic acid is replaced with another dicarbon such as isophthalic acid, and a portion of the ethylene glycol is replaced with another diol such as 2,2-bis(4-hydroxyphenyl)propane. Furthermore, the heat-shrinkable yarn may also be a yarn having a core-sheath structure.

[0021] The heat-shrinkable yarn in this invention preferably has a shrinkage rate of 20% or more at 180°C for 15 minutes, and more preferably 40% or more at 180°C for 15 minutes. There is no particular upper limit, but the shrinkage rate at 180°C for 15 minutes is usually 90% or less.

[0022] According to this knitted fabric, at least one of the layers contains heat-shrinkable yarn having a shrinkage rate of 20% or more at 180°C for 15 minutes, so good moldability can be obtained through heat shrinkage. For example, when manufacturing shoes using this knitted fabric, the knitted fabric is cut to create the minimum number of parts necessary to manufacture the shoe body, such as an upper member and a sole member. These are then sewn together to produce a bag-shaped intermediate product. Next, this intermediate product is placed in a mold and heat-set, causing the intermediate product to heat-shrink and forming a shoe body that conforms to the mold. In this invention, the embodiment of the heat-shrinkable yarn is not particularly limited, but it is preferable that it be inserted into the layers for superior moldability. By obtaining such good moldability, it is possible to handle complex shapes. Therefore, by suppressing process subdivision, etc., processability is improved and manufacturing costs can be reduced. The shrinkage rate can be calculated according to JIS L 1013:2021 8.18.2 Method B.

[0023] Furthermore, in this invention, at least one of the upper or lower layers contains thicker fibers than the fibers that mainly constitute the base fabric. The layer in which the thicker fibers are woven becomes a firm and resilient surface. It is also preferable that the thicker fibers are included in only one of the upper or lower layers. By including the thicker fibers in only one of the upper or lower layers, the other layer, which does not contain the thicker fibers, can be made the surface that comes into contact with the skin, thus forming a surface with a softer feel. In this invention, thicker fibers refer to fibers with a higher total fineness than the other fibers that mainly constitute the base fabric (hereinafter sometimes referred to as "base fabric yarn"). These fibers are preferably multifilaments.

[0024] The total fineness ratio (thick fiber / ground yarn) between the thick fibers and the base yarn is preferably 1.5 or higher, and more preferably 1.8 or higher. This makes it possible to give the fabric an appropriate firmness and body. Furthermore, the total fineness ratio (thick fiber / ground yarn) between the thick fibers and the base yarn is preferably 5.0 or lower, and more preferably 3.5 or lower. In addition, the total fineness of the base yarn is preferably 100 dtex or more and 500 dtex or less, and the total fineness of the thick fibers is preferably 150 dtex or more and 1750 dtex or less. The fineness of the single yarns constituting the multifilament is not particularly limited and can be appropriately selected depending on the situation such as yarn breakage during knitting. Increasing the single yarn fineness makes it possible to give a firmness and body, while conversely, decreasing it makes it possible to make it flexible and soft to the touch.

[0025] If there are multiple thick fibers, the weight-averaged value of their total fineness is used. Also, if there are multiple ground yarns, the total fineness of the yarn that accounts for the largest weight in the knitted fabric is used.

[0026] Furthermore, in order to better exhibit the effects described above, it is preferable that the thick fibers be included in the knitted fabric in an amount of at least 5% by weight, and more preferably 8% by weight or more. Also, in relation to the other fibers that mainly constitute the knitted fabric, it is preferable that the amount of thick fibers be 40% by weight or less, more preferably 30% by weight or less in terms of flexibility, and even more preferably 20% by weight or less.

[0027] Furthermore, in the present invention, it is preferable that at least one of the upper or lower layers has multiple openings. Here, "opening" refers to a location where a continuous row of knitting in the vertical direction is not connected to an adjacent row of knitting in the horizontal direction as a knit structure or via an inserted yarn. The presence of openings allows the stress associated with thermal shrinkage of the knitted fabric to be relieved by these openings, thereby preventing wrinkles from forming in the knitted fabric (especially the other layer) due to thermal shrinkage, resulting in superior moldability. In this case, the area ratio of openings per unit area of ​​the knitted fabric (= 100 × area of ​​openings in the unit area of ​​the knitted fabric / unit area of ​​the knitted fabric) is preferably 1% or more, more preferably 10% or more, and even more preferably 15% or more. Also, from the viewpoint of improving the feel against the skin, the area ratio of openings is preferably 60% or less, and more preferably 40% or less. By limiting the upper limit of the ratio of openings in this way, it is possible to suppress the discomfort caused by skin rubbing against large openings and to make the fabric feel better against the skin. Here, the area ratio of openings can be calculated by the method described in the examples.

[0028] Furthermore, the opening may be formed by the base fabric forming the upper or lower layer, or by the presence or absence of lateral connections between the knitted rows constituting the base fabric using inserted yarn. By using a knitted fabric, the opening can be easily enlarged without using inserted yarn, further improving workability and the feel against the skin. Moreover, it is preferable to use a knitted fabric for one of the upper or lower layers and inserted yarn for the other. In this way, the knitted fabric can be used as the surface in contact with the skin to improve the feel against the skin, while the inserted yarn can provide firmness and resilience.

[0029] Furthermore, it is preferable that a portion of at least one of the upper or lower layers includes a different structure from the base structure. By doing so, in addition to forming a surface with firmness and resilience by knitting in fibers thicker than those constituting the base structure, it is possible to more firmly connect adjacent base structure threads, thereby further enhancing the firmness and resilience. Moreover, depending on the structure formed, it is possible to further enhance the firmness and resilience in specific directions or in all directions. For example, when the knitted fabric of the present invention is used as the upper material of a shoe, the inside of the shoe can be made soft to the touch, and the outer surface can be made firm to the foot during walking or exercise, resulting in a shoe with good hold and comfort.

[0030] In this invention, it is preferable that the connecting portion connects the upper layer and the lower layer with a gap of 1 mm or more and 10 mm or less. By making the gap 1 mm or more, the knitted fabric can be made bulkier, thereby providing a soft touch and feel. Furthermore, by heat setting, one of the upper or lower layers will conform to the other layer, and all layers can be formed into the desired shape. Also, by making the gap 10 mm or less, a knitted fabric with fewer wrinkles and superior moldability can be obtained. The connecting portion can be determined by subtracting the thickness of the upper and lower layers from the thickness of the knitted fabric.

[0031] Furthermore, it is preferable that at least a portion of the connecting portion is composed of multifilaments. This configuration allows for a soft touch and feel. The total fineness of the multifilaments preferably used in the connecting yarn is 100 dtex or more and 2000 dtex or less, more preferably 150 dtex or more and 1700 dtex or less, and even more preferably 150 dtex or more and 1000 dtex or less. When the total fineness of the multifilaments is 100 dtex or more, the necessary bending rigidity is easily secured, and when it is 2000 dtex or less, it becomes easier to handle during knitting fabric manufacturing.

[0032] The single filament fineness of the multifilament is preferably between 1 dtex and 10 dtex, and more preferably between 2 dtex and 6 dtex. When the single filament fineness of the multifilament is 1 dtex or more, it is easier to ensure the necessary bending rigidity and to form a crimp shape on one of the threads. When the single filament fineness of the multifilament is 10 dtex or less, it is less likely to feel rough to the touch and it is easier to obtain a soft texture.

[0033] This configuration allows for a knitted fabric that is both heat-shrinkable, highly bulky, and has excellent flexibility, resulting in a pleasant feel against the skin.

[0034] As described above, in the present invention, the upper and lower layers are connected by a connecting part, and from the viewpoint of bulkiness, the thickness of the knitted fabric is preferably 2 mm or more, and more preferably 3 mm or more. Furthermore, from the viewpoint of moldability, the thickness of the knitted fabric is preferably 15 mm or less, and more preferably 10 mm or less.

[0035] Furthermore, in the present invention, it is preferable that at least one of the upper and lower layers is made up of fused yarn in part or in whole. According to this embodiment, when the knitted fabric is heat-set, the yarns are fused together by the fused yarn, so that a textile product with excellent shape retention in addition to moldability can be produced. In the present invention, the fused yarn is not particularly limited, and conventionally known fibers such as low melting point polyester can be used as appropriate.

[0036] Examples of fused yarns include monofilament yarns that have core-sheath type or side-by-side type heat-fusible fibers and are composed of only one heat-fusible fiber.

[0037] Furthermore, examples of the fused yarn include a multifilament yarn having multiple heat-fusible fibers, and a multifilament yarn having one heat-fusible fiber and one or more non-heat-fusible fibers.

[0038] In this context, "non-heat-fusible fibers" refer to fibers that do not exhibit fusion properties even at temperatures at which heat-fusible fibers can be heat-fused.

[0039] Specifically, if the heat-fusible fiber is of the core-sheath type and the resin constituting the sheath is a crystalline resin exhibiting a specific melting point (Tm(°C)), then "non-heat-fusible fiber" means a fiber whose surface is formed at least of a crystalline resin having a melting point higher than Tm(°C), or an amorphous resin having a glass transition temperature higher than Tm(°C).

[0040] Furthermore, if the heat-fusible fiber is of the core-sheath type and the resin constituting the sheath is an amorphous resin exhibiting a specific glass transition temperature (Tg(°C)), then "non-heat-fusible fiber" means a fiber whose surface is formed at least of a crystalline resin having a melting point higher than Tg(°C), or an amorphous resin having a glass transition temperature higher than Tg(°C).

[0041] Furthermore, it is preferable that at least a portion of the fused yarn in the present invention is elastomer elastic yarn (hereinafter sometimes simply referred to as "elastic yarn"). In this way, a textile product with excellent flexibility in addition to moldability and shape retention can be obtained. In the present invention, it is preferable that the elastic yarn is contained in an amount of 5% to 35% by weight of the entire knitted fabric. More preferably 30% by weight or less, and even more preferably 25% by weight or less.

[0042] The elastic yarn is preferably a monofilament, and more preferably a core-sheath composite monofilament consisting of a core component and a sheath component. In the case of a core-sheath composite monofilament, one or both of the sheath component and the core component can be made of a polyester elastomer. However, from the viewpoint of improving the adhesion between the core component and the sheath component, it is preferable that the core component and the sheath component contain each other's components, and it is more preferable that the core component and the sheath component are made of similar components, such as a polyester elastomer. In particular, it is even more preferable that the core component and the sheath component are copolymers composed of multiple components that each contain common components, and that the core component and sheath component have different melting points by changing the composition ratio of these multiple components.

[0043] Furthermore, it is preferable that the melting point of the sheath component be at least 10°C lower than the melting point of the core component. In particular, a core-sheath composite fiber having a core component made of a polyester elastomer with a melting point of 190-250°C and a sheath component made of a polyester elastomer with a melting point of 140-190°C is most preferable in terms of adhesion during heat setting and yarn strength. By making the melting point of the monofilament sheath component at least 10°C lower than the melting point of the monofilament core component, the melting of the core component is suppressed, thereby suppressing a decrease in strength, while the sheath portion of the monofilament can fuse the yarns together. The melting point can be measured according to JIS L1013:2021.

[0044] The fused portion in the sheath may be only a part of it, but it is more preferable that the entire sheath is fused to the other threads. Note that the above-mentioned core-sheath composite thread or non-composite monofilament can also be used without fusion.

[0045] Furthermore, the fused yarn may function as the heat-shrinkable yarn described above. Specifically, the fused yarn is preferably one that shrinks by 20% or more at 180°C for 15 minutes, and more preferably one that shrinks by 40% or more at 180°C for 15 minutes. There is no particular upper limit, but it is usually 90% or less at 180°C for 15 minutes. Examples of such yarns include fibers made from polyester elastomers, and examples of polyester elastomers include "Hytrel" (registered trademark) manufactured by Toray DuPont.

[0046] Furthermore, in the knitted fabric of the present invention, it is preferable that at least one side of the fabric has a heat shrinkage rate of 10 to 60%. If the values ​​of one side and the other side are different, it is more preferable that the side with the higher heat shrinkage rate has a heat shrinkage rate of 10 to 60%. In this way, it becomes possible to heat-form the knitted fabric to create complex product shapes. It is preferable that the heat shrinkage rate is within this range in at least one of the course direction and the wale direction. The heat shrinkage rate can be measured by the method described in the examples.

[0047] In this invention, the knitted fabric is preferably a warp-knitted fabric. By using a warp-knitted fabric, it is possible to suppress stitch slippage and other issues before shaping, while still having moldability.

[0048] Next, an embodiment of the present invention will be described with reference to the figures. Figures 1A to 1E and Figures 2 to 5 are explanatory diagrams showing the structure of the warp-knitted fabric 1 as a knitted fabric according to this embodiment. As shown in Figures 1A to 1E, the warp-knitted fabric 1 according to this embodiment is composed of an upper layer 2, a lower layer 3, and a connecting part 4 that connects the upper layer 2 and the lower layer 3.

[0049] The upper layer 2 is formed to extend in the course direction, which is perpendicular to the knitting direction, and consists of multiple chain stitch rows 2a arranged in the course direction, and insertion yarns 2b and 2c inserted into the chain stitch rows 2a. Similarly, the lower layer 3 is formed to extend in the course direction, which is perpendicular to the knitting direction, and consists of multiple chain stitch rows 3a arranged in the course direction, and insertion yarns 3b and 3c inserted into the chain stitch rows 3a are connected by connecting yarns 4a and 4b that constitute the connecting part 4. In addition, in the warp-knitted fabric 1 of this example, at least one of the layers of the upper layer 2 and the lower layer 3 contains heat-shrinkable yarn. Furthermore, the base structure of the upper layer 2 is formed by chain stitch rows 2a, and similarly, the base structure of the lower layer 3 is formed by chain stitch rows 3a. In the present invention, in addition to chain stitch rows 2a, a thicker fiber 2d is used to constitute a part of the upper layer 2.

[0050] In Figure 1A, only three chain stitch rows 2a of the upper layer are shown, and the other chain stitch rows 2a are omitted for the sake of clarity of the structure. Similarly, only three chain stitch rows 3a of the lower layer are shown, and the other chain stitch rows 3a are omitted. The connecting section 4 is also provided in a line in the direction of the course, but in Figure 1A, only one row is shown, and the other rows are omitted. In Figures 1B to 1E, some yarns are omitted for the sake of clarity of the structure. In Figure 1B, the relationship between the chain stitch rows 2a of the upper layer 2 and the inserted yarns 2b and 2c is shown in an enlarged view for clarity, and similarly in Figure 1D, the relationship between the chain stitch rows 3a of the lower layer 3 and the inserted yarns 3b and 3c, as well as the opening 6, are shown in an enlarged view for clarity. In Figure 1E, the definition of the distance h between the upper layer 2 and the lower layer 3 is shown. Note that in Figures 1A to 1E, fibers 2d that are thicker than the knitting yarns that make up the ground fabric are not shown.

[0051] Furthermore, as shown in Figures 1A to 1E, the inserted yarns 2b and 2c are inserted across multiple chain stitch rows 2a of the upper layer 2, and as shown in Figure 1C, the portions where the inserted yarns 2b and 2c are not inserted become openings 5 ​​in the upper layer 2 (see, for example, the dashed ellipse in Figure 1C). Numerous such openings 5 ​​are scattered throughout the upper layer 2. Similarly, as shown in Figure 1D, the inserted yarns 3b and 3c are inserted across multiple chain stitch rows 3a in the lower layer 3, and the portions where the inserted yarns 3b and 3c are not inserted become openings 6 in the lower layer 3 (see, for example, the dashed ellipse in Figure 1D), and numerous such openings 6 are also scattered throughout the lower layer 3.

[0052] A warp-knitted fabric 1 having such a structure can be knitted using a known double raschel knitting machine equipped with two rows of needle beds arranged opposite to each other, each having multiple knitting needles, and a supply mechanism for supplying a predetermined yarn to the needle beds.

[0053] Specifically, in one needle bed (the front needle bed), the chain stitch rows 2a and 2d of the upper layer 2 are knitted using the yarn supplied from the supply mechanism, while inserting yarns 2b and 2c into multiple chain stitch rows 2a in the wale direction. Then, in the other needle bed (the back needle bed), the chain stitch rows 3a of the lower layer 3 are knitted using the yarn supplied from the supply mechanism, while inserting yarns 3b and 3c into multiple chain stitch rows 3a knitted in the wale direction, and connecting yarns 4a and 4b connect the upper layer 2 and the lower layer 3.

[0054] At this time, loops are formed on the insertion yarn side (the side facing the needle bed on the right side) of the upper layer 2 by the connecting yarns 4a and 4b. These loops are inserted into the stitches of the insertion yarns 2b and 2c, thereby securing the insertion yarns 2b and 2c. Meanwhile, the connecting yarns 4a and 4b are bonded to the insertion yarns 3b and 3c. As a result, a three-dimensional warp-knitted fabric 1 is formed in which the upper layer 2 and the lower layer 3 are connected by the connecting yarns 4a and 4b.

[0055] Thus, with the warp-knitted fabric 1 of this example, when manufacturing a textile product using it, the warp-knitted fabric 1 can be cut into the minimum necessary number of parts, then sewn together, and then heat-set to form the desired shape. This simplifies the manufacturing process and allows the textile product to be manufactured in a short time. Furthermore, by forming numerous openings 5 ​​and 6 in the upper layer 2 and lower layer 3, the stress associated with thermal shrinkage during heat-setting of the warp-knitted fabric 1 is relieved by these openings 5 ​​and 6, thereby preventing wrinkles from forming in the warp-knitted fabric 1 due to thermal shrinkage.

[0056] In the warp-knitted fabric 1 of this example, there are no restrictions on the yarns used for the chain stitch rows 2a, 3a and connecting yarns 4a, 4b and insert yarns 2b, 2c, 3b, 3c, but examples include filament yarns such as polyester yarn, nylon yarn, and rayon yarn, as well as spun yarn. However, heat-shrinkable yarn is used for at least one layer of the yarns used in the chain stitch rows 2a and insert yarns 2b, 2c that constitute the upper layer 2, and the yarns used in the chain stitch rows 3a and insert yarns 3b, 3c that constitute the lower layer 3. In this example, the base structure of both the upper and lower layers is shown as chain stitch and connected by connecting yarn, but it is also possible to use a knitting structure where the layer using heat-shrinkable yarn is composed of chain stitch and insert yarn, and the other layer does not use insert yarn.

[0057] The connecting section 4 preferably connects the upper layer 2 and the lower layer 3 with a gap of 1 to 10 mm between them. Furthermore, the yarn used in the chain stitch rows 4a, 2a, and 3a is preferably made of multifilament, and more preferably polyester multifilament.

[0058] It is preferable that the upper layer 2 and the lower layer 3 are each composed of part or all of the fused yarn described above. For example, part or all of the knitting yarns constituting the upper layer 2 and the lower layer 3 can be made of low-melting-point polyester yarn (fused yarn). Furthermore, it is preferable that at least one of the fused yarns used in the upper layer 2 and the lower layer 3 is an elastic yarn formed from elastomer in at least part. For example, at least one of the inserted yarns 2b and 2c of the upper layer 2 and the inserted yarns 3b and 3c of the lower layer 3 can be an elastic yarn. With the above configuration, when manufacturing a desired textile product using the warp-knitted fabric 1, it is possible to obtain a textile product with excellent thermoformability and shape retention.

[0059] The uses of the knitted fabric of the present invention are not particularly limited, but it can be suitably used for the outer covering of shoes and bags, and is particularly suitably used for the upper material of shoes. [Examples]

[0060] Examples and comparative examples of the present invention will now be described in detail, but the present invention is not limited thereto. Each measurement item was measured by the method described below.

[0061] (1) Thickness The thickness of the knitted fabric was determined in accordance with JIS L 1096:2010 8.4 Method A. After applying pressure of 0.7 kPa for 10 seconds, the thickness of the knitted fabric was measured at three points, and the average value (mm) was calculated and rounded to two decimal places.

[0062] (2) Fineness and the ratio of the total fineness of thick fibers to the ground yarn The fiber fineness was measured in accordance with JIS L 1013:2021 8.3.1 Method B. The total fineness ratio of the thicker fibers to the ground yarn was calculated by dividing the fineness of the thicker fibers by the fineness of the ground yarn, and rounding the result to one decimal place.

[0063] (3) Thermal shrinkage rate (dry heat dimensional change rate) in knitted fabrics In accordance with JIS L 1913:2010 6.10.3, the knitted fabric was sampled to a size of 20cm x 20cm, and 100mm was measured at the center of each side in the warp (wale direction) and weft (cours direction) directions, and two marks were made in each direction. Next, the samples were suspended in a 180°C dryer for 3 minutes, which was changed to 5 minutes, and left there. After removal and cooling to room temperature, the length L between the two points was measured, and the dry heat dimensional change rate ΔL was calculated using the following formula, and the simple average of three measurements was taken.

[0064]

number

[0065] Here, ΔL is the dry heat dimensional change rate (%), and L is the length between the two points (mm). The dry heat dimensional change rate obtained in this way was defined as the heat shrinkage rate of the knitted fabric in this invention. Table 1 shows the values ​​for the side with the larger heat shrinkage rate.

[0066] (4) Heat shrinkage rate (dry heat dimensional change rate) of heat shrinkable yarn The dry heat dimensional change rate of heat-shrinkable yarn was calculated according to JIS L 1013:2021 8.18.2 Method B. Specifically, an initial load was applied to the yarn, two points were marked at a precise distance of 500 mm, the initial load was removed, the yarn was suspended in a 180°C dryer for 15 minutes, then removed and cooled to room temperature, the initial load was applied again, the length L between the two points was measured, and the dry heat dimensional change rate ΔL (%) was calculated using the following formula and the simple average of five measurements was taken.

[0067]

number

[0068] Here, ΔL is the dry heat dimensional change rate (%), and L is the length between the two points (mm). The dry heat dimensional change rate obtained in this way was defined as the heat shrinkage rate of the heat-shrinkable yarn in this invention.

[0069] (5) Area ratio of openings A rectangle measuring 21 cm vertically and 27 cm horizontally was drawn on the surface of the knitted fabric to measure the ratio of opening area. A color photograph was taken of this rectangle with a resolution of 1920 x 1080 pixels. The area corresponding to the opening was colored in using image processing, and the number of pixels corresponding to black was measured. The area ratio (= area of ​​opening per unit area / unit area) was calculated by taking the ratio of this number to the total number of pixels. The area ratio was calculated by performing the above evaluation method five times and simply averaging the values ​​obtained in each trial.

[0070] (6) Fusion The knitted fabric was sampled in 10mm x 10mm in size, and the cross-section of the obtained sample was observed at 100x magnification using a scanning electron microscope (SEM) to check for the presence or absence of fusion between fibers. Sufficient fusion was evaluated as "A", good fusion as "B", and insufficient fusion as "C".

[0071] (7) Moldability (processability) After cutting the knitted fabric into upper and sole materials for the shoe, these were sewn together to form a bag. Then, the sewn bag-shaped components were fitted into a shoe last and heat-treated at 180°C for 15 minutes to obtain the shoe material for the shoe body. The moldability was evaluated visually, with "A" indicating no wrinkles and sufficient moldability, "B" indicating almost no wrinkles and good moldability, and "C" indicating wrinkles and insufficient moldability.

[0072] (8) Texture The shoe materials obtained in the above (7) evaluation of moldability were evaluated by touching their inner surfaces by hand. A rating of "A" was given for a very smooth and excellent feel, "B" for a smooth and good feel, and "C" for a slightly rough feel that was considered unsatisfactory.

[0073] (9) firmness and resilience For the shoe material obtained in the evaluation of moldability described in (7) above, the firmness and resilience of its outer surface were evaluated by touching it by hand, and were rated as "A" if sufficient, "B" if good, and "C" if somewhat insufficient.

[0074] [Example 1] The fabric was knitted using a double raschel knitting machine and the knitting method described above. Specifically, as shown in Figure 2, a chain knitting row 2a was knitted using a chain knitting reed L3 that guides a full set of chain knitting yarn to form the base fabric, and an insertion yarn reed L2 that guides a full set of insertion yarn 2b was used to insert the insertion yarn 2b in a zigzag pattern into each wale knitted by the chain knitting reed L3 to form the base fabric. In addition, thicker fibers 2d than the knitting yarns that make up the base fabric were pulled out of the reed L1 in a 2-in, 2-out manner and guided in to knit chains and form the upper layer 2. In the lower layer 3, similar to the upper layer 2, a chain knitting row 3a was knitted using a chain knitting reed L6 that guides a full set of chain knitting yarn, and an insertion yarn reed L7 that introduces a full set of insertion yarn 3b was used to insert the insertion yarn 3b in a zigzag pattern into each wale knitted by the chain knitting reed L6 to form the lower layer 3. Furthermore, the inserted thread 2b of the upper layer 2 and the inserted thread 3b of the lower layer 3 were connected by two connecting thread reeds L4 and L5, which guided the connecting threads 4a and 4b by pulling them out one by one in each case.

[0075] [Example 2] Instead of the lower layer insertion yarn 3b in the warp knitted fabric of Example 1, two insertion yarn reeds L7 and L8, each pulling out and guiding the yarn with a 3-in, 1-out pattern, were used to insert the insertion yarns 3b and 3c in a zigzag pattern along each wale of the chain knitting made by the chain knitting reed L6, as shown in Figure 3. In addition, the yarns were inserted with alternating left-right and right-handed swings over one or several wales for each required course corresponding to the opening 6, thereby forming the lower layer 3.

[0076] [Example 3] In Example 2, the lower layer 3 was knitted using reeds L6 and L7 as shown in Figure 4, so that no insert yarn was used in the lower layer 3, and an opening 6 was formed by the knitting structure.

[0077] [Example 4] Instead of the thick fiber 2d used in Example 3, two reeds L1 and L2, each using fibers 2d and 2e thicker than the fibers 2a that constitute the base structure of the upper layer 2, were used to guide the yarn by pulling them out at a rate of 1 in and 5 out, respectively, to create the knitted structure shown in Figure 5. Together with the chain stitch yarn 2a, the upper layer 2 was formed.

[0078] [Comparative Examples 1-3] Each of the examples 1-3 was formed without using fibers 2d thicker than the base fabric in the warp knitted fabric. The knitted structures of each example are shown in Figures 6-8.

[0079] In Examples 1-4 and Comparative Examples 1-3, the base yarns 2a and 3d constituting the upper layer 2 of the warp-knitted fabric, and the connecting yarns 4a and 4b connecting the upper layer 2 and lower layer 3, were each made of 167dtex-48 filament polyester multifilament yarn. Similarly, the insert yarns 3b and 3c constituting the lower layer 3 of Examples 1 and 2 and Comparative Examples 1 and 2 were also made of the same 167dtex-48 filament polyester multifilament yarn. Furthermore, as the thicker fibers 2d and 2e, Examples 1-3 used 334dtex-96 filament polyester multifilament yarn, while Example 4 used 501dtex-144 filament polyester multifilament yarn.

[0080] Furthermore, in the warp-knitted fabrics of Examples 1-4 and Comparative Examples 1-3, a 400 dtex polyester monofilament elastic yarn was used for the insert yarn 2b constituting the upper layer 2. This monofilament elastic yarn is an elastic yarn in which Toray DuPont's "Hytrel" (registered trademark) 6347 (melting point 215°C) is used as the core component and "Hytrel" (registered trademark) 4056 (melting point 153°C), also a thermoplastic polyester elastomer, is used as the sheath component. After drying each pellet, they were melted in separate extruders, weighed using gear pumps, and supplied to an extruder in a composite pack, where they were extruded to produce yarn with a mass ratio of core:sheath = 70:30. The heat shrinkage rate of the above elastic yarn was 41%. That is, it was confirmed that the insert yarn 2b functions as both a heat-fusible yarn and a heat-shrinkable yarn.

[0081] Furthermore, the warp-knitted fabrics of Examples 1-4 and Comparative Examples 1-3 are knitted fabrics in which the size of the openings 6 is varied in various ways as shown in the table by adjusting the structure of the knitted fabric and adjusting the connection ratio between adjacent ground structure rows 3a of the lower layer 3. Note that although the warp-knitted fabrics of Example 1 and Comparative Example 1 do not intentionally form openings 6, openings exist as stitches.

[0082] Then, the warp-knitted fabrics of Examples 1-4 and Comparative Examples 1-3 were cut into upper and sole materials for the shoes, respectively. These were then sewn into a bag shape, and the sewn bag-shaped components were fitted into a shoe mold. A heat treatment was then performed at 180°C for 15 minutes to obtain the shoe material for the shoe body.

[0083] [Table 1]

[0084] As shown in Table 1, Examples 1-4, compared to Comparative Examples 1-3, maintained a good feel against the skin while exhibiting superior moldability (processability) and firmness, making them suitable for use as upper materials for shoes, where the fabric is molded into a three-dimensional shape for wear. In particular, by knitting thicker fibers in the upper layer compared to the base yarn, the firmness was improved, the shrinkage rate of the knitted fabric was moderately suppressed, wrinkles that occurred in the lower layer were inhibited, and moldability (processability) was also excellent.

[0085] Although specific embodiments of the present invention have been described above, the embodiments that the present invention can adopt are not limited to those described above. [Explanation of Symbols]

[0086] 1 Warp knitted fabric 2 Upper layer 2a geological formation 2b, 2c Insertion sutures 2d, 2e: Fibers thicker than the yarns that make up the base fabric. 3 Lower layer 3a, 3d geological column 3b, 3c insertion thread 4 Connecting part 4a, 4b Connecting thread 5, 6 Openings

Claims

1. A knitted fabric having a three-dimensional structure consisting of an upper layer, a lower layer, and a connecting part that connects the upper and lower layers, Of the upper or lower layers, at least one of them contains a heat-shrinkable yarn having a shrinkage rate of 20% or more at 180°C for 15 minutes, in part or in whole. Of the aforementioned upper or lower layers, at least one of the layers has thicker fibers woven into it, relative to the fibers that mainly constitute the ground tissue. The aforementioned thick fiber is a multifilament, A knitted fabric having a thermal shrinkage rate of 10-60% on at least one side.

2. The knitted fabric according to claim 1, wherein at least one of the upper or lower layers has a plurality of openings.

3. The knitted fabric according to claim 1 or 2, wherein at least one of the upper or lower layers includes a structure different from the ground fabric in a part thereof.

4. The knitted fabric according to claim 1 or 2, wherein the thickness is 2 to 15 mm.

5. The knitted fabric according to claim 1 or 2, wherein at least a portion of the connecting portion is made of multifilament.

6. The knitted fabric according to claim 1 or 2, wherein at least one of the upper and lower layers is made up of fused yarn in part or in whole.

7. The knitted fabric according to claim 6, wherein at least a portion of the fused yarn is an elastomer elastic yarn.

8. The knitted fabric according to claim 7, wherein the elastic yarn is a monofilament.

9. The knitted fabric according to claim 8, wherein the elastic yarn is a core-sheath composite monofilament consisting of a core component and a sheath component.

10. The knitted fabric according to claim 9, wherein the sheath component of the elastic yarn has a melting point at least 10°C lower than the melting point of the core component.

11. The knitted fabric according to claim 9, wherein the sheath component of the elastic yarn is a polyester elastomer.

12. The knitted fabric according to claim 9, wherein the core component of the elastic yarn is a polyester elastomer.

13. The knitted fabric according to claim 1 or 2, which is a warp-knitted fabric.

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