Composite spun yarn and woven or knitted fabric

Abstract

To provide a composite spun yarn that includes a prescribed quantity or more of nylon 56 short fibers and natural fibers or cellulosic fibers, has excellent tensile strength, and enables a woven or knitted fabric having excellent anti-pilling and anti-static properties to be obtained.SOLUTION: A composite spun yarn is a spun yarn whose cross section perpendicular to a yarn longitudinal direction has island parts and sea parts. The composite spun yarn has two or more island parts with respect to one sea part. Fiber constituting the island parts contains 40 mass% or more of nylon 56 short fibers. Fiber constituting the sea part contains 50 mass% or more of natural fibers or cellulosic fibers. Content of the nylon 56 short fibers in the spun yarn is 20 mass% or more. The composite spun yarn has 230 cN or more of tensile strength, 5 to 25% of elongation percentage, 40 (fuzz / 10 m) or less of the number of fuzz of 3 mm or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a conjugate spun yarn having one sea portion and two or more island portions in a cross section perpendicular to the longitudinal direction of the yarn, in which the island portions contain nylon 56 staple fibers, and which can give woven or knitted fabrics having excellent strength, anti-pilling properties, and antistatic properties, and to a woven or knitted fabric obtained from the spun yarn. [Background technology]

[0002] In recent years, as development towards the SDGs (Sustainable Development Goals) progresses, and as environmental awareness increases on a global scale, there is a demand for the development of non-petroleum-based fiber materials due to the problems of depletion of petroleum resources and global warming caused by mass consumption of petroleum resources.

[0003] Using plant resources that grow by absorbing carbon dioxide from the atmosphere as raw materials, it is hoped that the circulation of carbon dioxide can help curb global warming, and it may also be possible to solve the problem of resource depletion. For this reason, biomass-derived plastics have been attracting attention in recent years. For example, polylactic acid is known. However, compared to polyamide, it is inferior in various properties such as heat resistance, impact resistance, and hydrolysis resistance, and its applications are greatly limited.

[0004] Polyamide fibers, such as nylon 6 and nylon 66, are used in many clothing applications due to their excellent thread strength, moisture absorption, abrasion resistance, deep dyeability, ease of advanced processing, etc. In addition, polyamide fibers are moisture absorbent, so they can suppress static electricity generation caused by friction when worn compared to polyester fibers. However, these general-purpose polyamide fibers are derived from petroleum-based raw materials. For this reason, nylon 56, nylon 11, and other polyamides that use non-petroleum-based raw materials in part or in whole are attracting attention.

[0005] As a fiber using nylon 56, Patent Document 1 proposes a spun yarn made of hygroscopic nylon 56 staple fibers. Patent Document 1 shows that the spun yarn made of nylon 56 staple fibers has higher hygroscopicity than the general-purpose polyamide fiber, but the antistatic properties of woven and knitted fabrics obtained from this spun yarn are insufficient compared to natural fibers such as cotton, and when used in underwear, mid-layer clothing, sportswear, etc., it is not possible to suppress the generation of static electricity due to friction when worn.

[0006] On the other hand, as a method for manufacturing spun yarn, a method for producing composite spun yarn having a core-sheath structure is known (Patent Documents 2 and 3), and various functionalities can be imparted by selecting various types of fibers to be arranged in the core and the sheath. For example, by arranging a high-strength fiber in the core to provide strength and a fiber with a pleasant texture in the sheath, a spun yarn having practical strength and a pleasant texture can be obtained. However, due to its structure, a spun yarn having a core-sheath two-layer structure in which different materials are arranged has a poor binding strength between the fibers at the boundary between the core and the sheath. In other words, the binding strength between the fibers is poor compared to a blended yarn in which different materials are mixed at the fiber level. When the binding strength between the fibers is poor, fluffing tends to occur, and there is a concern that the tensile strength of the yarn and the anti-pilling properties of a fabric using the spun yarn may also be reduced due to insufficient binding strength.

[0007] Methods to solve this problem include covering with filaments, increasing the number of twists during spinning, making two-ply yarns, etc. However, these methods tend to result in a stiff texture and feel, and it has been difficult to improve strength and anti-pilling properties while maintaining the texture. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent Publication No. 2011-157639 [Patent Document 2] Special Publication No. 59-20774 [Patent Document 3] Special Publication No. 5-85655 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made to solve the above-mentioned problems, and has as its technical object to provide a conjugate spun yarn which is a conjugate spun yarn of nylon 56 staple fiber and natural fiber or cellulosic fiber, and which has excellent tensile strength and is capable of suppressing yarn fuzz without impairing the texture and feel, and which can give woven or knitted fabrics which are excellent in anti-pilling properties and anti-static properties, and a woven or knitted fabric using said conjugate spun yarn. [Means for solving the problem]

[0010] The present inventors have conducted extensive research to solve the above problems and have arrived at the present invention. That is, the present invention relates to the following (1) to (4). (1) A composite spun yarn having an island portion and a sea portion in a cross section perpendicular to the longitudinal direction of the yarn, the composite spun yarn having two or more island portions in one sea portion, the fibers constituting each island portion containing 40% by mass or more of nylon 56 staple fiber, the fibers constituting the sea portion containing 50% by mass or more of natural fiber or cellulosic fiber, the content of nylon 56 staple fiber in the spun yarn being 20% ​​by mass or more, the composite spun yarn having a tensile strength of 230 cN or more, an elongation of 5 to 25%, and the number of fluffs of 3 mm or more measured according to JIS-L-1095 General Spun Yarn Testing Method for "Fluff" 9.22.2B method being 40 or less (pieces / 10 m). (2) The composite spun yarn according to (1), characterized in that when the composite spun yarn is knitted into a tubular fabric, the frictional electrification voltage in the warp direction (friction fabric: wool) is 800 V or less. (3) The composite spun yarn of (1) or (2), in which the sea portion contains 50% by mass or more of cotton fibers. (4) Woven or knitted fabrics containing the composite yarn of (1). Effect of the Invention

[0011] The composite spun yarn of the present invention has two or more island parts in one sea part, and contains a specific amount of nylon 56 staple fiber in the island part and natural fiber or cellulosic fiber in the sea part, so that the tensile strength of the yarn is improved and fluffing is less likely to occur. Therefore, when it is made into a woven or knitted fabric, it is possible to obtain a fabric with excellent anti-pilling properties and texture. In addition, since the composite spun yarn contains 20% by mass or more of nylon 56 staple fiber as a whole, it is possible to fully utilize the moisture absorption property of nylon 56 staple fiber, and it is possible to obtain a woven or knitted fabric with excellent antistatic properties. The woven or knitted fabric of the present invention contains the composite spun yarn of the present invention, and is therefore a suitable material for clothing applications such as underwear, intermediate wear, and sportswear. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic side view showing an example of a roving machine for producing a roving yarn. [Diagram 2] FIG. 1 is a schematic plan view showing an example of a roving machine for producing a roving yarn. [Diagram 3] 1 is a schematic perspective view of a spinning machine for producing a composite spun yarn of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention will be described in detail below. The composite spun yarn of the present invention is a spun yarn having an island portion and a sea portion in a cross section perpendicular to the longitudinal direction of the yarn. That is, it is a composite form in which independent island portions exist within a sea portion. By making each island portion covered with fibers forming the sea portion, the fiber group forming the island portion, particularly the fiber group of the island portion present at the boundary between the island portion and the sea portion, and the fiber group of the sea portion present at the boundary between the island portion can have a strong binding force, and the fiber group constituting the sea portion can also have a binding force. As a result, fuzz from the yarn surface is suppressed, the tensile strength of the yarn is improved, and woven and knitted fabrics using the spun yarn have excellent anti-pilling properties. Note that when staple fibers are used as constituent fibers of the spun yarn, the fibers are easily entangled when assembled, and the binding force can be further strengthened. Therefore, in the present invention, it is preferable that both the island portion and the sea portion are composed of only staple fibers.

[0014] The composite spun yarn of the present invention has two or more island parts in one sea part of the composite spun yarn, and each island part is required to be covered by the fiber group of the sea part without the fiber bundles of each island part being in close contact with each other. For example, in a so-called core-sheath composite form in which one core part is covered by the sea part, the binding at the boundary between the fiber group forming the core part and the fiber group forming the sea part is weak, and there is a concern that a part of the fiber group of the sea part may fall off or the strength may decrease due to pulling or abrasion. In contrast, in the composite spun yarn of the present invention, the fiber group of the sea part existing between multiple island parts forms an anchor to increase the binding force between the fiber bundles of the island parts and the fiber group of the sea part, resulting in increased durability against pulling and abrasion and improved strength and anti-pilling properties.

[0015] The number of island parts is not limited, but in consideration of effectively achieving the islands-in-sea structure and favorably covering each island part with the sea part, 2 to 4 is preferable. Furthermore, in consideration of stability during spinning, 2 is more preferable. If there are 5 or more island parts, it becomes difficult to cover each island part with the fiber constituting the sea part without adhering them to each other, and the fiber bundles constituting the island parts tend to become too thin, which may cause operational problems such as sliver breakage during spinning.

[0016] The mass ratio of the island parts (total of the island parts) to the sea part in the composite spun yarn is preferably 20:80 to 50:50, more preferably 20:80 to 45:55. If the mass ratio of the sea part is 50% by mass or more, when the island parts are covered with the fibers of the sea part, each of the two or more island parts is covered without being in close contact with each other, and a stable composite cross-sectional form can be obtained. In addition, by making the ratio of the island parts 20% by mass or more, the characteristics and functions of the nylon 56 fiber arranged in the island parts can be fully expressed.

[0017] Next, the island portion will be described. The fibers constituting each island contain 40% by mass or more of nylon 56 staple fiber, preferably 45% by mass or more, more preferably 70% by mass or more, and particularly preferably 80% by mass or more. That is, in the case of a conjugate spun yarn having two islands, each island contains 40% by mass or more of nylon 56 staple fiber. When the content of nylon 56 staple fiber in each island is 40% by mass or more, the excellent strength and moisture absorption of nylon 56 staple fiber allows the conjugate spun yarn of the present invention to have a specific tensile strength described later and also has excellent frictional electrification voltage.

[0018] The nylon 56 in the present invention is a resin produced by a polycondensation reaction with pentamethylenediamine and adipic acid as main constituent units. It is preferable to use pentamethylenediamine produced from a biomass raw material.

[0019] Each island portion contains 40% by mass or more of nylon 56 staple fibers, and may contain fibers other than nylon 56 staple fibers. Examples of fibers other than nylon 56 staple fibers include natural fibers or cellulosic fibers used in the sea portion, and synthetic fibers such as polyester, nylon, acrylic, polyolefin, para-aramid, meta-aramid, and polyarylate, and may contain only one type or multiple types. In particular, in consideration of dyeability and texture, it is preferable to use the same natural fibers or cellulosic fibers as those in the sea portion. As fibers other than nylon 56 staple fibers, filaments can also be used, but it is preferable to use only staple fibers as the fibers constituting the island portions, because the fibers are easily entangled when made into a sliver, which strengthens the binding force and improves the strength of the resulting spun yarn.

[0020] Next, the sea portion will be described. The sea portion contains natural fibers or cellulosic fibers at 50% by mass or more, preferably at 60% by mass or more, and more preferably at 80% by mass or more. If the content of natural fibers or cellulosic fibers in the sea portion is less than 50% by mass, the composite spun yarn of the present invention will be inferior in antistatic properties, dyeability, and texture.

[0021] The natural fibers in the present invention include plant fibers and animal fibers. Plant fibers include cotton and hemp, and animal fibers include wool and silk. Cellulosic fibers in the present invention include short regenerated cellulosic fibers such as viscose rayon and Tencel (modal, lyocell). The sea portion may contain only one type of these fibers or may contain multiple types. Among them, it is preferable that the sea portion contains 50% by mass or more of cotton, taking into consideration antistatic properties, dyeability, and texture.

[0022] The sea portion contains 50% by mass or more of natural fibers or cellulosic fibers, and may contain fibers other than natural fibers or cellulosic fibers. Examples of fibers other than natural fibers or cellulosic fibers include synthetic fibers such as polyester, nylon, acrylic, polyolefin, para-aramid, meta-aramid, and polyarylate. Among them, it is preferable to use fibers such as acrylic, taking into consideration dyeability and texture. The fibers constituting the sea portion may be either staple fibers or filaments. However, it is preferable to use only staple fibers as the fibers constituting the sea portion, because the fibers are more likely to entangle with each other when made into a sliver, which strengthens the binding force and improves the strength of the resulting spun yarn.

[0023] The composite spun yarn of the present invention has a nylon 56 staple fiber content of 20% by mass or more, more preferably 40% by mass or more, and from the viewpoint of environmental consideration, preferably 55% by mass or more. By containing 20% ​​by mass or more in the spun yarn, it is possible to fully exhibit the strength and moisture absorption properties of the nylon 56 staple fiber, and the composite spun yarn has excellent tensile strength, elongation, and frictional electrification voltage.

[0024] The tensile strength of the composite spun yarn of the present invention is 150 cN or more, and preferably 160 to 500 cN. If it is less than 150 cN, the workability during weaving and knitting of woven or knitted fabrics will be poor, and the resulting woven or knitted fabrics will have poor durability. On the other hand, to achieve a tensile strength of more than 500 cN, the count of the composite spun yarn must be small, which tends to make it unsuitable for clothing applications.

[0025] The composite spun yarn of the present invention must have an elongation of 5 to 25%, preferably 7 to 20%, so that the resulting woven or knitted fabric can be suitably used for clothing such as underwear, mid-layer clothing, sportswear, etc. If the elongation is within the above range, the weaving and knitting properties are good, and the resulting woven or knitted fabric will have excellent quality.

[0026] The composite spun yarn of the present invention has a fluff count of 3 mm or more, measured according to JIS-L-1095 General Spun Yarn Testing Method "Fluff" 9.22.2B, of which 40 (pieces / 10 m) or less, more preferably 30 (pieces / 10 m) or less. Also, the fluff count of 5 mm or more is preferably 20 (pieces / 10 m) or less, more preferably 10 (pieces / 10 m) or less. In normal spun yarns, when there is a large amount of fuzz, the strength of the spun yarn is significantly reduced, which tends to cause problems in weaving and knitting, and the more long fuzz there is, the more likely the woven or knitted fabric is to suffer from pilling. On the other hand, the composite spun yarn of the present invention has a form having multiple island and sea parts, and the binding between the fiber groups is strengthened, so that the number of fuzzes is small enough to satisfy the above range. As a result, the average strength is excellent, and when it is made into a woven or knitted fabric, it has excellent anti-pilling properties.

[0027] As a method for setting the fluff index within the above range, in addition to the method of forming the spun yarn into a form having a plurality of island portions and a sea portion as described above, a method of introducing a compact spinning system during ring spinning in order to increase the density of fiber bundles in the spun yarn production process, which will be described in detail in the description of the production method below, can also be used.

[0028] When the composite spun yarn of the present invention is made into a cylindrical knitted fabric, the frictional electrification voltage in the warp direction is 800V or less, preferably 500V or less, and more preferably 400V or less when wool is used for the friction cloth. The frictional electrification voltage in the weft direction is preferably 800V or less, more preferably 500V or less, and even more preferably 400V or less. When cotton is used for the friction cloth, the frictional electrification voltage in the warp direction is preferably 2000V or less, more preferably 1700V or less, and even more preferably 1600V or less. The frictional electrification voltage in the weft direction is preferably 2000V or less, more preferably 1700V or less, and even more preferably 1600V or less. If the frictional electrification voltage satisfies the above range, when a woven or knitted fabric using the spun yarn of the present invention is used for clothing, the generation of static electricity due to friction or the like during wearing can be suppressed. Note that the frictional charging voltage in the warp direction refers to the value of the frictional charging voltage in the wale direction of the tubular knitted fabric in the frictional charging voltage measurement method described below, and the frictional charging voltage in the weft direction refers to the value of the frictional charging voltage in the course direction of the tubular knitted fabric.

[0029] As described above, the composite spun yarn of the present invention is characterized by having a layered structure in which nylon 56 staple fibers are arranged in the island portions and natural fibers or cellulosic fibers are arranged in the sea portion. That is, since the nylon 56 staple fibers in the island portions are surrounded by natural fibers or cellulosic fibers having a higher hygroscopicity than nylon 56 staple fibers, the composite spun yarn can have better antistatic properties than a spun yarn in which nylon 56 staple fibers are arranged to occupy most of the spun yarn surface. Furthermore, since nylon 56 staple fibers themselves have hygroscopicity, the composite spun yarn has better antistatic properties than a spun yarn in which polyester fibers having low hygroscopicity are used in the island portions. Furthermore, in the present invention, by adopting a layered structure consisting of a plurality of island portions and a sea portion as described above, it is possible to obtain a spun yarn that has, in addition to antistatic properties, excellent tensile strength due to the nylon 56 staple fibers in the island portions and excellent dyeability and texture due to the natural fibers or cellulosic fibers in the sea portion.

[0030] The frictional electrification voltage is measured using a processed tubular knitted fabric obtained by knitting and scouring only the composite spun yarn of the present invention in the manner described below, in accordance with the frictional electrification voltage measurement method described in JIS L 1094:2014 Method B (wool (and cotton) is used as the friction cloth). (Knitting method) A cylindrical knitted fabric is obtained using a cylindrical knitting machine manufactured by Eiko Sangyo Co., Ltd. (boiler diameter: 3.5 inches, number of needles: 260N). (dyeing and finishing) The obtained knitted fabric is subjected to the following treatments (scouring, bleaching, dyeing, drying) using a mini-color to obtain a finished tubular knitted fabric. (scouring) Sodium hydroxide 5g / l, Sunmol 1g / l, bath ratio 1:50, treatment temperature: 80℃ x 20 minutes (Hot water wash / dry) Wash with hot water, spin-dry with a mangle, then hang to dry

[0031] Furthermore, the conjugate spun yarn of the present invention preferably has a twist coefficient K of 3.2 to 5.7, more preferably 3.4 to 4.2. If the twist coefficient K is within the above range, it is possible to improve the strength and anti-pilling properties without impairing the texture. In addition, from the viewpoints of suppressing fuzz, improving anti-pilling properties, and providing an excellent texture, the Worcester unevenness (U%) is preferably 15.0% or less, more preferably 13.0% or less. In this way, the composite spun yarn of the present invention has an appropriate twist and small thickness unevenness, which enhances the binding between the fibers and provides excellent strength and anti-pilling properties. In addition, the frictional electrification voltage is small and tends to be stable, providing excellent antistatic properties, and the quality and feel of the resulting woven or knitted fabric is also likely to be excellent.

[0032] Since the conjugate spun yarn of the present invention is suitable for clothing applications such as underwear, mid-layers, and sportswear, it is preferable that the British cotton count is 5 to 60, and more preferably 10 to 50.

[0033] In order to obtain the above-mentioned composite spun yarn of the present invention, it is preferable to use nylon 56 staple fibers for the island portions having a fiber length of 30 to 80 mm, a tensile strength of 2.5 to 5.5 cN / dtex, and an elongation of 35 to 95%. Furthermore, it is preferable to use nylon 56 short fibers having a heat shrinkage rate of 1.5 to 2.0% and a shrinkage rate of 5 to 15%. By making the composite spun yarn contain 40% by mass or more of nylon 56 staple fibers having such characteristic values ​​in each island portion of the composite spun yarn and 20% by mass or more in the spun yarn, it is possible to obtain a composite spun yarn that satisfies the above-mentioned characteristic values.

[0034] When using natural fibers or cellulosic fibers for the sea portion, for example, cellulosic fibers preferably have a fiber length of 25 to 64 mm, and the single fiber fineness is preferably in the range of 0.5 to 6.0 dtex, more preferably 1.0 to 5.0 dtex.

[0035] Next, the method for producing the spun yarn of the present invention will be described. First, a roving having a sheath-core two-layer structure is prepared by arranging the fibers to be arranged in the "island portion" of the composite spun yarn in the core portion and the fibers to be arranged in the "sea portion" of the composite spun yarn in the sheath portion. At least two rovings having the obtained sheath-core two-layer structure are simultaneously passed through the back roller of a ring spinning machine, without being in close contact with each other and with a space therebetween. Then, after being drawn out and drafted by passing through the back roller-apron-front roller, the rovings having the sheath-core structure are twisted together before being wound around a wooden tube to stably obtain a composite spun yarn. At this time, the number of island portions of the obtained spun yarn is determined by the number of rovings passed through the back roller of the ring spinning machine. That is, when the rovings are twisted together to obtain a composite spun yarn, the core portion becomes the island portion of the spun yarn, and the sheath portion is twisted together, and the sheath portions are entangled and integrated to form the sea portion. By twisting together a plurality of drafted fiber bundles (rovings), the fluff on the surfaces of the fiber bundles is twisted and entangled with each other, which also has the effect of reducing fluff in the resulting spun yarn.

[0036] Here, the manufacturing method of the present invention will be specifically described with reference to the drawings. First, to obtain the roving yarn having the core-sheath two-layer structure, in the roving process, two types of slivers (sliver S1 and sliver S2) are prepared, and the sliver S1 is used as the core, and the sliver S2 is wound around the sliver S1 to form the sheath. Specifically, first, to obtain the carded sliver for the core, nylon 56 staple fibers and other fibers as necessary are mixed and fed into a mixing and punching machine to obtain a sheet-like wrap. This wrap is fed into a carding machine, and after a carding process in the carding machine, the web is spun, bundled, and pressed with a calendar roll to obtain a carded sliver for the island portion. On the other hand, to obtain the carded sliver for the sheath, natural fibers or cellulosic fibers and other fibers as necessary are mixed, and then the carded sliver for the sheath is obtained in the same manner as above.

[0037] Next, a plurality of card slivers for the core and sheath are combined and drawn in a drawing process to obtain a sliver S1 for the core and a sliver S2 for the sheath. Next, using a roving frame having the structure shown in Figure 1 (schematic cross-sectional view) and Figure 2 (schematic cross-sectional view), slivers S1 and S2 are supplied as shown in Figure 2, the angle θ of the sliver S1 moving toward the flyer head with respect to the draft direction in Figure 2 is set to 60°, and the sliver S2 is wound around the sliver S1. The roving is then wound while providing a false twist effect by the flyer, thereby forming a roving yarn having a core-sheath structure in which the sliver S1 is the core and the sliver S2 is the sheath.

[0038] Here, it is preferable to adjust the mass ratio of the sliver S1 that forms the core and the sliver S2 that forms the sheath so that (core layer):(sheath layer) = 20:80 to 50:50, and it is particularly preferable to make such a distribution taking into consideration various factors such as the specific gravity, strength, and crimp of the fibers. Moreover, it is preferable that the number of twists in the roving step is set to a degree that does not cause poor drawing in the subsequent fine spinning step. For example, the twist coefficient K can be adjusted to 0.4 to 1.5.

[0039] Next, Fig. 3 is a schematic diagram of a spinning machine for obtaining the spun yarn of the present invention. In detail, the rovings (1, 1') having a core-sheath structure are introduced at intervals to the back roller (2), and the rovings (slivers) are drafted between the back roller (2), apron (3), and front roller (4) with a certain interval (W) between them. The drafted rovings are then twisted together between the front roller (4) and snail guide (5), and the composite spun yarn (6) is wound up to obtain a composite spun yarn having two island parts per sea part. The number of island parts in the composite spun yarn is determined by the number of rovings introduced to the back roller.

[0040] Here, it is important that the rovings introduced to the back roller are introduced at intervals without being in close contact with each other, and are joined and twisted together after being drafted to the front roller. If the drafting process is performed in a close contact state, the drafted rovings will pass over the fiber bundles, making it difficult to maintain a uniform core-sheath structure. The interval between the rovings may be adjusted appropriately depending on the material of the fiber used, the mass of the rovings, the draft rate, etc., and is preferably 2.5 mm to 20 mm, and more preferably 3.5 mm to 14 mm. If the interval is less than 2.5 mm, there is a concern that the drafted rovings will be in close contact with each other, and conversely, if the interval exceeds 20 mm, there is a concern that spinning defects such as breakage of the rovings or the twisted fiber bundles when introduced to the back roller or when twisted after leaving the front roller will occur. In addition, depending on the width of the rollers in the spinning machine, the sliver will be gripped at both ends of the rollers, which may lead to poor yarn quality and poor spinning operation due to insufficient nip.

[0041] Furthermore, in the present invention, composite spun yarn can also be obtained by compact spinning in addition to the above method.

[0042] Compact spinning is a method in which, during spinning, a slit-shaped suction device and a mesh apron (compact device) are attached near the front roller as needed, so that the convergence of the fiber bundle (fleece), which was reduced during drafting, is improved again on the mesh by the suction force of the slits (this type of spinning method is sometimes called compact spinning). This reduces fuzz on the surface of the spun yarn, increasing its strength and imparting an excellent luster to the woven or knitted fabric.

[0043] The number of twists in the spinning process is not particularly limited, but from the viewpoint of physical properties (strength, fluff, etc.) and texture, the twist factor K is preferably in the range of 3.2 to 5.7, and more preferably in the range of 3.5 to 4.5. A loose twist such as a twist factor K of less than 3.2 may cause the yarn to slip out or may deteriorate the physical properties (particularly pilling) when woven or knitted. Conversely, increasing the twist factor K can achieve a certain improvement in strength and crispness, but if it is too high, exceeding 5.7, it may easily lead to defects such as poor productivity, hardening of the texture, or poor seams and snare.

[0044] The twist factor K can be calculated using the following formula. Twist factor (K) = number of twists (times / 2.54 cm) / √(British cotton count)

[0045] The woven or knitted fabric of the present invention contains the composite spun yarn of the present invention. The content of the composite spun yarn of the present invention contained in the woven or knitted fabric is preferably 50% by mass or more, more preferably 70% by mass or more in order to achieve the object of considering environmental issues, and it is particularly preferable that the content is 100% by mass, i.e., the woven or knitted fabric is made only of the composite spun yarn of the present invention.

[0046] The woven or knitted fabric is not particularly limited in structure. Examples of the woven fabric include plain, twill, satin, pile, and variations of these structures. The knitted fabric may be either a warp knit or a weft knit. Examples of the warp knit include denby knit, cord knit, and atlas knit, and more specifically, tricot half and tricot satin. Examples of the weft knit include plain knit, rib knit, purl knit, and smooth knit, and more specifically, jersey, pique, and smooth.

[0047] The woven or knitted fabric of the present invention includes the composite spun yarn of the present invention, and is a spun yarn in which the nylon 56 staple fibers arranged in the island portion are covered with a sea portion containing natural fibers or cellulosic fibers. Therefore, compared with a spun yarn in which nylon 56 staple fibers are abundantly present on the yarn surface, it has excellent dyeability and color fastness. That is, it shows high color development by dyeing with a dye, and can suppress discoloration and staining such as yellowing during repeated use of the woven or knitted fabric. Therefore, it is preferable that the woven or knitted fabric of the present invention has a predetermined washing fastness. Specifically, it is preferable that the discoloration and staining in the washing fastness measured according to the JIS L0844 A-2 method are both grade 4 or higher. If the washing fastness satisfies this range, color fading due to washing and color transfer to other laundry are unlikely to occur. EXAMPLES

[0048] The present invention will now be described in detail with reference to examples. Various property values ​​and evaluations in the examples are as follows.

[0049] (Measurement of count) The composite spun yarn thus obtained was used and measured in accordance with JIS L-1095 9.4.1. (Measurement of twist number) The composite spun yarn thus obtained was used and measured in accordance with JIS L-1095 9.15.1, Method B. (Tensile strength / elongation) The composite spun yarn thus obtained was used to carry out measurements in accordance with JIS L-1095 9.5 under the conditions of a tensile tester: ST-2000 manufactured by Shikishima Boseki Co., Ltd., a pulling speed of 30 cm / min, and a gripping distance of 50 cm. (Number of fluff) The obtained composite spun yarn was tested using an F-INDEX TESTER (manufactured by Shikishima Techno Co., Ltd.) in accordance with the "Fluff" 9.22.2B method of the JIS-L-1095 general spun yarn test method, and the number of 3mm (3mm or more) and 5mm (5mm or more) fluffs (pieces / 10m) was measured. (pilling) The resulting processed fabric was treated for 10 hours according to JIS-L-1076 Pilling Test Method for Woven and Knitted Fabrics, Method A (method using an ICI type tester), and measurements were taken, with the results being expressed as a grade. Grade 3 or higher is desirable for anti-pilling properties. (Worcester spot (U%)) The composite spun yarn obtained was measured using a yarn unevenness tester (KET-80V / B manufactured by Keisokuki Kogyo Co., Ltd.) at a measurement speed of 200 m / min and a measurement time of 2 minutes in accordance with JIS L-1095 9.20.1, Method A.

[0050] (friction charging voltage) Measured and calculated as above.

[0051] (Stainability) The resulting processed fabric was visually evaluated by panelists on the following two-level scale. ○: Dyed to the desired color. ×: Not dyed to the desired color (light color). (Color fastness assessment) The resulting processed fabric was used to evaluate washing fastness according to JIS L-0842 A-2 method.

[0052] The nylon 56 staple fiber and cotton sliver used in the examples are as follows: Nylon 56 staple fiber (S1); Single yarn size 1.90 dtex, Tenacity 3.63 cN / dtex, Elongation 88.4%, Fiber length 39.6 mm, Heat shrinkage 1.8%, Shrinkage 10.5% Cotton sliver (S2): Combed sliver made of 100% cotton, with an effective fiber length of 32.8 mm, short fiber content of 9.4%, and fineness (micron leading) of 4.3 according to the JIS L 1019 cotton fiber testing method.

[0053] Example 1 (Sliver S1) The above-mentioned nylon 56 staple fiber alone was fed into a mixing and punching machine to obtain a sheet-like wrap. The wrap was fed into a carding machine, and after a carding process in the carding machine, a web was spun, bundled, and pressed with a calendar roll to obtain a carded sliver of 235 grains / 6 yards. Next, the carded sliver was drawn twice in a drawing process, with the eight strands being drawn a total of 9.4 times, to obtain a sliver S1 of 200 grains / 6 yards. (Sliver S2) A cotton sliver was prepared as sliver S2.

[0054] A sliver S1 was prepared as the sliver for the core portion, and a sliver S2 was prepared as the sliver for the sheath portion. Using a roving frame having the structure shown in Figure 1 (schematic cross-sectional view) and Figure 2 (schematic cross-sectional view), a sliver S1 for the core and a sliver S2 for the sheath were supplied so that the mass ratio of each sliver after drawing was S1:S2 = 40:60. The angle θ of the sliver S1 for the core to the flyer head relative to the draft direction in Figure 2 was set to 60°, and a roving with a roving mass of 180 gr / 30 yd (1 gr = 0.65 g, 1 yd = 0.9144 m) and a twist number of 0.76 turns / 2.54 cm was obtained. The two rovings were passed through the back rollers of a compact spinning machine (Toyota Industries Corporation, RX300) having the structure shown in Figure 3 with a gap of 7 mm between them, and drafted between the back roller, apron, and front roller at a draft ratio of 43.2 times. The two fiber bundles drafted between the front roller and snail guide were then twisted together and spun with a twist number of 20.8 turns / 2.54 cm (twist coefficient K = 3.8) to obtain a composite spun yarn of the present invention having a count of 30 (British cotton count). The resulting composite spun yarn was used for the warp and weft to weave a plain weave fabric with a warp density of 104 threads / 2.54 cm and a weft density of 76 threads / 2.54 cm. The resulting fabric was subjected to the dyeing and finishing treatments described below (scouring, presetting, dyeing, drying, and final setting) to obtain a processed fabric. (scouring) Sunmol 1g / l, bath ratio 1:50, 80℃ x 20 minutes (Preset) Pin tenter, 170℃ x 1 min (staining) Acid dye: Nylosan Blue NFL (180%) 1%omf, Levelan NKD 2%omf, acetic acid 0.2cc / l, bath ratio 1:50, 100℃ x 30 minutes Reactive dye: Sumifix Spura Blue BRF 1%omf, mirabilite 60g / l, soda ash 20g / l, processing temperature: 60℃ x 45 minutes Soaping, rinsing and drying: Lipotol RK-5 1g / l, treatment temperature: 100℃ x 10 minutes, rinse with water, dehydrate with a mangle and hang dry.

[0055] Comparative Example 1 A roving yarn was obtained in the same manner as in the Example, except that sliver S1 was used as the sliver for the core portion, sliver S2 was used as the sliver for the sheath portion, the mass ratio of each sliver after drawing was S1:S2 = 30:70, the roving yarn mass was 275 gr / 30 yd (1 gr = 0.65 g, 1 yd = 0.9144 m), and the twist number was 0.76 turns / 2.54 cm. This single roving was used for spinning in a compact spinning machine (RX300, manufactured by Toyota Industries Corporation). Specifically, the single roving was passed through the trumpet (guide) of the spinning machine, passed through the back roller, apron, and front roller in this order, and stretched 35.6 times. After that, the yarn was twisted in the Z direction to a twist factor of 3.8 (twist number 20.8 times / 2.54 cm), to obtain a two-layered spun yarn of count 30 (British cotton count). This two-layered spun yarn had only one island portion per sea portion. The obtained two-layered spun yarn was used to obtain a plain weave greige fabric in the same manner as in Example 1, which was then dyed and finished in the same manner as in Example 1 to obtain a finished fabric.

[0056] Comparative Example 2 A two-layer spun yarn having a count of 30 (British cotton count) was obtained in the same manner as in Comparative Example 1, except that the mass ratio of the sliver S1 for the core portion and the sliver S2 for the sheath portion after drawing was set to S1:S2 = 40:60. This two-layer spun yarn had only one island portion per sea portion. The obtained two-layer structured yarn was used to obtain a plain weave greige fabric in the same manner as in Example 1, which was then dyed and finished in the same manner as in Example 1 to obtain a processed fabric.

[0057] The evaluation results of the composite spun yarn, two-layer spun yarn, and finished fabric obtained in Example 1 and Comparative Examples 1 and 2 are shown in Table 1.

[0058] [Table 1]

[0059] As is clear from Table 1, the composite spun yarn obtained in Example 1 satisfied the constitution stipulated in the present invention, and therefore it was possible to obtain a woven or knitted fabric that satisfied the characteristic values ​​such as tensile strength, elongation, and fuzz count, and was also excellent in anti-pilling properties and friction voltage resistance. Furthermore, the obtained woven fabric was excellent in dyeability and color fastness, as well as antistatic properties.

Claims

1. A composite spun yarn having an island portion and a sea portion in a cross section perpendicular to the longitudinal direction of the yarn, wherein the number of island portions in one sea portion of the composite spun yarn is two or more, the fibers constituting each island portion contain 40% by mass or more of nylon 56 staple fibers, the fibers constituting the sea portion contain 50% by mass or more of natural fibers or cellulosic fibers, and the content of nylon 56 staple fibers in the spun yarn is 20% by mass or more; The tensile strength is 230cN or more, and the elongation rate is 5 to 25%. The composite spun yarn is characterized in that the number of fluffs of 3 mm or more measured according to the "Fluff" 9.22.2B method in the JIS-L-1095 general spun yarn testing method is 40 or less (pieces / 10 m).

2. 2. The composite spun yarn according to claim 1, characterized in that when the composite spun yarn is knitted into a tubular fabric, the frictional electrification voltage in the warp direction (friction fabric: wool) is 800 V or less.

3. The composite spun yarn according to claim 1 or 2, wherein the sea portion contains 50 mass % or more of cotton fibers.

4. A woven or knitted fabric comprising the composite spun yarn according to claim 1.

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