Twisted yarn and fiber structure

Abstract

A twisted yarn according to the present invention comprises: a long and narrow core; a slit tape in which a coating layer is directly formed by printing on at least one surface of a base sheet that contains paper, said coating layer having one surface thereof exposed; and a long and thin restraining yarn that is wound around the core and the slit tape.

Description

Twisted yarn and fiber structures

[0001] The present invention relates to a twisted yarn, more specifically, a twisted yarn made from paper. The present application also relates to a fiber structure made from the twisted yarn. This application claims priority from Japanese Patent Application No. 2024-120195, filed on July 25, 2024, the contents of which are incorporated herein by reference.

[0002] A twisted yarn made of paper (hereinafter, sometimes referred to as a "paper yarn") is known. A paper yarn is usually made by twisting together long, thin strips of paper.

[0003] There is a demand for imparting various functions to paper yarn. In Patent Document 1, in order to prevent thread breakage during weaving, which is one of the drawbacks of paper yarn, filaments made by cutting thin Japanese paper made from Manila hemp are twisted and then immersed in a tank containing molten wax.

[0004] Japanese Patent Application Publication No. 11-172541

[0005] The layer formed on the surface of the paper yarn by impregnation may crack or peel off during subsequent transportation, bending, etc., depending on its physical properties. Furthermore, when imparting multiple functions to the paper yarn using this method, the surface layer becomes thicker by sequentially impregnating the paper yarn with multiple chemical solutions. This may make the layer more susceptible to peeling or reduce the flexibility of the paper yarn, making it harder to handle.

[0006] In view of the above circumstances, an object of the present invention is to provide a twisted yarn that has a highly stable imparted function.

[0007] A first aspect of the present invention is a twisted yarn comprising an elongated core material, a base paper made of paper on which a coating layer is directly formed by printing on at least one side, a slit through which the coating layer is exposed on one side, and an elongated holding thread wound around the core material and the slit.

[0008] A second aspect of the present invention is a fiber structure formed using the twisted yarn according to the first aspect.

[0009] According to the present invention, a twisted yarn having highly stable imparted functions can be provided.

[0010] 1A and 1B are schematic diagrams showing slits used in a twisted yarn according to one embodiment of the present invention, and are schematic diagrams showing other examples of slits. 2A and 2B are diagrams showing the structure of a twisted yarn according to one example.

[0011] An embodiment of the present invention will be described with reference to Figs. 1 to 3. The twisted yarn according to this embodiment is formed by twisting together at least one core material, at least one paper slit, and at least one holding thread. Fig. 1 shows a schematic diagram of a slit 10. The slit 10 has a configuration in which a coating layer 12 is formed on one side of a base paper 11. Since the coating layer 12 according to this embodiment contains a flame retardant, the slit 10 exhibits flame retardancy based on the flame retardant.

[0012] The base paper 11 according to the present embodiment is not limited to ordinary paper made from plant-derived pulp, but may be any sheet-like structure formed by a wet papermaking method using a fibrous material. For example, a sheet-like structure formed by a wet papermaking method using a fibrous material made from synthetic resin can be used as the base paper 11 according to the present embodiment, or a sheet formed by mixing synthetic resin and natural pulp can also be used. Paper with a clearly textured surface, such as crepe paper with a wrinkled surface or embossed paper, can also be used as the base paper 11. The natural pulp is not limited to virgin pulp, and may include recycled pulp. The thickness of the base paper 11 can be, for example, approximately 20 to 500 μm.

[0013] The coating layer 12 can be formed by various known coating methods, such as die coating, or various known printing methods, such as screen printing and gravure printing. As is clear from the above, the coating layer 12 does not necessarily need to completely cover one side of the base paper 11 with the material constituting the coating layer. For example, the coating layer 12 may be formed in a striped pattern on one side of the base paper 11, leaving a region where the base paper 11 is partially exposed on one side. Alternatively, the coating layer may cover the entire base paper 11 from a macroscopic perspective, but the material constituting the coating layer may be arranged in a large number of fine dots from a microscopic perspective. Such a coating layer formation mode makes it easy to adjust the degree of functionality exhibited by the coating layer by changing the size and density of the dots. However, it goes without saying that the coating layer 12 may also be formed so as to completely cover one side of the base paper 11 with no gaps. In any of the above embodiments, the thickness of the coating layer 12 may be, for example, approximately 2 to 100 μm.

[0014] The width of the slit 10 can be about 1 to 50 mm. If the width of the slit 10 is 15 mm or less, it becomes easy to form a twisted yarn using a plurality of slits 10.

[0015] The core material to be combined with the slit 10 is not particularly limited as long as it is long and thin, but is typically a thread containing fibers. When fibers are used, natural or synthetic fibers can be used. For both, either single fibers or fibers twisted together with multiple strands can be used. Twisted yarns made by twisting multiple types of fibers can also be used. Examples of natural fibers include cotton, linen, wool, and silk. Examples of synthetic fiber materials include polyethylene, polypropylene, polyester, nylon, acrylic, vinylon, polyolefin, para-aramid, meta-aramid, polyarylate, polybenzoxazole, and modacrylic fibers, as described below. Furthermore, recycled fibers such as rayon can also be used as the core material. The thickness of the core material can be approximately 10 to 5,500 decitex. In addition to fibers, another slit 10 or a paper slit without a coating layer can also be used as the core material. The paper used as the core material can be similar to the base paper 11 described above, and the slit width can be the same as that of the slit 10.

[0016] The holding threads are wound around the core material and the slits and twisted together. The holding threads can be the same as those used for the core material and can be of approximately the same thickness.

[0017] In the twisted yarn according to this embodiment, there is no particular limitation on the method for twisting the core material, the slit 10, and the holding yarn together, and any known appropriate method can be used. For example, the covering yarn method described in Japanese Patent No. 6930735 can be exemplified.

[0018] In the twisted yarn according to the present embodiment configured as described above, the coating layer 12 provided in the slit 10 exhibits flame retardancy. Therefore, a fabric made using this exhibits sufficient flame retardancy even though it contains a large amount of paper, and can therefore be suitably used for applications such as shades installed in homes.

[0019] In the twisting process for producing the twisted yarn according to this embodiment, the slits 10 are twisted together, resulting in irregular twisting. As a result, the coating layer 12 is not only present on the surface of the twisted yarn, but is also moderately distributed inside. This is a major difference from when a flame-retardant layer is formed by impregnation. Due to this difference in configuration, the coating layer 12 disposed inside the twisted yarn according to this embodiment is less susceptible to bending or friction on the outer surface. As a result, the function provided by the coating layer 12 can be more stably exerted. Furthermore, the holding threads also maintain an optimal state of contact between the core material and the slits.

[0020] In this embodiment, the function that can be imparted by the coating layer 12 is not limited to the flame retardancy described above. Other examples of functions include water repellency, hydrophilicity, toughness (resistance to breakage), chemical resistance, heat resistance, radio wave resistance, conductivity, light control, weather resistance, stain resistance, and sound control. In other words, as long as a material that exhibits the desired function is available, almost any function can be easily imparted to the twisted yarn by forming a coating layer 12 containing that material on the base paper 11. For example, paper containing a large amount of recycled pulp (e.g., 30% by mass or more) generally has inferior physical properties compared to paper made only from virgin pulp, making it difficult to use as the base paper 11 as is. However, by providing a coating layer 12 that exhibits the function of improving physical properties such as toughness, it becomes possible to use the twisted yarn as the slit 10. This also allows the twisted yarn to have a reduced environmental impact.

[0021] Furthermore, when the material of the base paper 11 is difficult to dye, such as aramid fiber, the coating layer 12 having the desired color (including fluorescent or luminous) can be provided to give the twisted yarn a desired appearance. In this case, the coating layer 12 gives the twisted yarn the function of "realizing an appearance that is difficult to achieve in view of the material of the base paper."

[0022] Two or more coating layers 12 may be provided in one slit. That is, as in slit 10A shown in Fig. 2, by forming a second coating layer 13 having a different composition from the coating layer 12 on the base paper 11, two types of functions can be imparted to the slit 10 and the twisted yarn formed using it, and it is also possible to add additional coating layers. The second coating layer may be formed on the coating layer 12, or on the side on which the coating layer 12 is not provided.

[0023] By forming two or more types of slits 10 with different coating layers 12, it is possible to impart multiple types of functions to the twisted yarn. In this case, if the colors of the coating layers in the slits used are different, the respective coating layers will be exposed to the outer surface in an irregular manner when twisted together, making it possible to produce a twisted yarn with a wide variety of appearances that is difficult to achieve with ordinary twisted yarns. It is also possible to create a configuration that combines the desired function and desired color.

[0024] The twisted yarn according to the present embodiment can be used to form woven or knitted fabrics. When creating a woven fabric using the twisted yarn according to the present embodiment, the twisted yarn can be used as either the warp or the weft, or both can be twisted yarns. There are no particular limitations on the weaving method, and various known methods such as plain weave, twill weave, and satin weave can be applied. For example, by forming a woven fabric using the twisted yarn according to the present embodiment as the weft and modacrylic fibers containing vinyl chloride, which have excellent flame retardancy, as the warp, it is possible to produce curtains, indoor blinds, etc. that are made of paper but have the flame retardancy specified by Japan's Fire Service Act. This modacrylic fiber has the advantage of being more slowly degraded by ultraviolet rays than aramid fibers, which also have excellent flame retardancy, and is therefore particularly suitable for fabrics to be used outdoors.

[0025] When producing the twisted yarn according to this embodiment, if the slit width is large, the slit may be inserted obliquely relative to the yarn path of the twisting machine. This reduces the contact area between the yarn path and the slit, preventing slit breakage due to frictional resistance. The slits of this embodiment, which have a coating layer, are harder than paper without a coating layer, making it difficult to transmit torque during twisting and prone to twisting unevenness. However, when the above-described procedure is used, the slits that pass through the yarn path are not positioned parallel to the core material. As a result, the twisted yarn 1 has a structure in which the slits 10 are wound spirally around the core material 20 without much twisting, and the pressure thread 30 is wound on top of them, as shown in FIG. 3 . The core material 20 serves to prevent the slits 10 from slipping away from the pressure thread 30 as the pressure thread 30 is wound around the slits 10. In this structure, the slits 10 behave like the curled cord of a fixed telephone, making the twisted yarn 1 less likely to break under longitudinal pulling force than in a structure in which the core material and the slits are arranged in a generally parallel arrangement and the hold-down thread is wrapped around them. Furthermore, when the hold-down thread is wrapped around a slit parallel to the core material, the slit tends to become rigid and rod-shaped due to the hold-down thread. However, the spiral slits do not form a rod and are held in place to a moderate extent so that they do not separate from the core material. This makes the twisted yarn 1 soft overall, allowing for suitable weaving and knitting despite the presence of a coating layer. There are no particular limitations on the degree of winding of the slits, and they can be wound, for example, between 2 and 2,000 times per meter of twisted yarn.

[0026] The twisted yarn according to this embodiment will be further described using examples. The technical scope of the present invention is not limited solely by the specific content of the examples.

[0027] (Example 1) (Preparation of slits) A mixture of 40 parts virgin pulp (N material), 20 parts recycled pulp, and 40 parts Manila hemp pulp was made into paper using a cylinder paper machine. ２A paper of Example 1 was obtained. A gravure printing machine was used to print an aqueous phosphorus-based flame retardant on both sides of the paper, forming a 5 μm-thick flame-retardant coating layer. The paper was cut to a width of 4 mm using a round-blade slitter to create the slits of Example 1. (Twisting Processing) One core cotton (10 count), three 4 mm slits, and one hold-down cotton (10 count) were single-covered using a covering twisting machine (Trytwister manufactured by Nippon Boshoku Machinery Co., Ltd.) to create the twisted yarn of Example 1. (Fabric Production) The twisted yarn of Example 1 was used as the weft, and a twisted yarn made of a polyvinyl chloride-containing modacrylic fiber and a polyester fiber was used as the warp. A woven fabric with an opening ratio of approximately 30% was created by twisting the warp and threading the weft using a loom.

[0028] (Example 2) (Preparation of slits) A mixture of 49 parts of virgin pulp (N material) and 51 parts of recycled pulp was made into paper using a cylinder paper machine. ２ A paper of this size was obtained. A flame-retardant coating layer similar to that used in Example 1 was formed on this paper. The paper was cut to a width of 1.5 mm using a round-blade slitter to create slits according to Example 2. (Twisting Processing) - One 167 decitex (150 denier) polyester filament yarn for the core material - One 1.5 mm slit - One polyester filament yarn for the holding thread core material was single-covered using the same covering twisting machine as in Example 1 to create the twisted yarn according to Example 2. (Fabric Production) The twisted yarn according to Example 2 was knitted using a Shima Seiki Mfg. Co., Ltd. whole garment flat knitting machine (15 gauge), and a knitted fabric was produced without any problems. This twisted yarn could also be knitted using a warp knitting machine.

[0029] (Example 3) The 4 mm slits used in Example 1 were used as the slits. One core modacrylic fiber (20 count), three 4 mm slits, and one holding thread modacrylic fiber (20 count) were single covered using the same covering twisting machine as in Example 1 to produce the twisted yarn of Example 3.

[0030] (Example 4) The 4 mm slits used in Example 1 were used as the slits. One core modacrylic fiber (20 count), three 4 mm slits, and one holding thread, the same polyester filament yarn as in Example 2, were single covered using the same covering twisting machine as in Example 1 to produce the twisted yarn of Example 4.

[0031] Example 5 The 4 mm slits used in Example 1 were used as the slits. Two core modacrylic fibers (20 count), three 4 mm slits, one hold-down thread (first layer) modacrylic fiber (20 count), and one hold-down thread (second layer) modacrylic fiber (20 count) were double covered using the same covering twisting machine as in Example 1 to produce the twisted yarn of Example 5.

[0032] (Example 6) (Preparation of slits) Only recycled pulp was made into paper using a cylinder paper machine. ２ A paper of the same size as in Example 1 was obtained. A flame-retardant coating layer similar to that in Example 1 was formed on this paper. The paper was cut to a width of 1.5 mm using a round-blade slitter to produce slits according to Example 6. (Twisting Processing) - Core: One 167 decitex (150 denier) polyester filament yarn - One 1.5 mm slit - Holding thread: One polyester filament yarn of the same type as the core material was single-covered using the same covering twisting machine as in Example 1 to produce the twisted yarn according to Example 6.

[0033] (Example 7) Example 7 is an example in which a layer of a predetermined color is used as a functional layer to realize a unique color. (Preparation of slits) A mixture of 40 parts virgin pulp (N wood), 20 parts recycled pulp, and 40 parts Manila hemp pulp was made into paper using a cylinder paper machine. ２A paper of Example 7 was obtained. Using a gravure printing machine, a yellow first color layer was formed over the entire surface of one side of the paper, and a red second color layer was formed over the entire surface of the other side, both using acrylic inks. The paper was cut to a width of 4 mm using a round-blade slitter to create the slits of Example 1. (Twisting Processing) One core cotton (10 count), three 4 mm slits, and one hold-down cotton (10 count) were single-covered using the same covering twisting machine as Example 1 to create the twisted yarn of Example 7. (Fabric Production) The twisted yarn of Example 7 was used as the weft, and a twisted yarn made of a polyvinyl chloride-containing modacrylic fiber and a polyester fiber was used as the warp. A woven fabric with a yellow and red mixture and an opening rate of approximately 30% was produced by twisting the warp and threading the weft using a loom. The color pattern of this fabric would have been difficult to achieve by dyeing the yarn.

[0034] (Example 8) Example 8 is an example in which a unique color is realized by adding another functional layer to the functional layer of a predetermined color. (Preparation of slits) An ethylene vinyl acetate adhesive of 20 g / m was applied to both sides of the paper on which the first color layer and the second color layer of Example 7 were provided. ２ A translucent polyester nonwoven fabric was coated and laminated to obtain paper with a lighter color for the first and second color layers. This paper had a color-adjusting layer made of a polyester nonwoven fabric, which was a separate functional layer, on the first and second color layers. The paper was cut to a width of 4 mm using a round-blade slitter to produce the slits of Example 8. (Twisting Processing) One core cotton (10 count), three 4 mm slits, and one hold-down cotton (10 count) were single-covered using the same covering twisting machine as Example 1 to produce the twisted yarn of Example 8. (Fabric Production) Using the twisted yarn of Example 8 as the weft and a twisted yarn made of a polyvinyl chloride-containing modacrylic fiber and a polyester fiber as the warp, the weft was twisted while the warp was woven using a loom to produce a pale yellow and red mixed woven fabric with an opening ratio of approximately 30%. The color profile of this fabric was not possible to achieve by dyeing the yarn.

[0035] (Example 9) (Preparation of slits) A mixture of 49 parts of virgin pulp (N material) and 51 parts of recycled pulp was made into paper using a cylinder paper machine. ２ A paper of the same size as in Example 1 was obtained. A flame-retardant coating layer similar to that in Example 1 was formed on this paper. The paper was cut to a width of 4 mm using a round-blade slitter to produce the slits of Example 1. (Twisting) - Core: One 167 dtex (150 denier) polyester filament yarn - Three 4 mm slits - Holding thread: One polyester filament yarn of the same type as the core material was single-covered using the same covering twisting machine as in Example 9, and the twisted yarn of Example 9 was produced without any problems. The tensile strength of the yarn of Example 9 was measured in accordance with JIS P8113:2006 and was found to be 33.5 N. For confirmation, an attempt was made to produce a fabric similar to that of Example 1 using the twisted yarn of Example 9. This was successful, confirming that the twisted yarn could withstand weaving using a loom.

[0036] Although one embodiment of the present invention has been described above, the specific configuration is not limited to this embodiment, and modifications and combinations of the configuration within the scope that does not depart from the gist of the present invention are also included.

[0037] For example, there is no particular limit to the number of core materials, slits, and holding threads in the twisted yarn according to the present invention, and the twisted yarn may be formed by using one or more of these materials in plural.

[0038] The woven fabric of the present invention is not limited to the embodiments shown in the examples, but may be a woven fabric using the twisted yarn of the present invention as the warp yarn or as both the warp yarn and the weft yarn. The warp or weft yarn used in combination with the twisted yarn of the present invention is also not limited to the modacrylic fiber shown in the examples. Furthermore, the twisted yarn of the present invention can be used for various fiber structures other than woven fabrics. Examples include various knitted fabrics such as braids and ropes, and sewing threads.

[0039] The present invention can be used to produce twisted yarns and various fiber structures.

[0040] REFERENCE SIGNS LIST 1 twisted yarn 10, 10A slit 11 base paper 12 coating layer 13 second coating layer 20 core material 30 holding thread

Claims

1. A twisted yarn comprising: an elongated core material; a base paper made of paper on which a coating layer is directly formed by printing on at least one surface, a slit where the coating layer is exposed on one surface; and an elongated holding thread wound around the core material and the slit.

2. The twisted yarn of claim 1, wherein the slits wrap around the periphery of the core material.

3. The twisted yarn of claim 1, wherein the coating layer contains a flame retardant.

4. The twisted yarn of claim 1, further comprising a second coating layer having a different composition than the coating layer.

5. The twisted yarn according to claim 1, wherein the base paper contains 30 mass percent or more of recycled pulp.

6. A fiber structure formed using the twisted yarn according to any one of claims 1 to 5.

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