Spun yarn, manufacturing method thereof, and fabric including the same

Abstract

To provide a spun yarn capable of obtaining a fabric having soft feeling, excellent tension, stiffness, and water-absorbing quick-drying property, a manufacturing method thereof, and the fabric including the same.SOLUTION: The invention is a spun yarn including 80 mass% or more of natural cellulosic fibers and regenerated cellulosic fibers. The spun yarn consists of a twistless fiber group in twistless state and a winding fiber group winding around the twistless fiber group, and includes 15 mass% or more and less than 85 mass% of the natural cellulosic fibers and more than 15 mass% and 85 mass% or less of the regenerated cellulosic fibers. Inner layer mixing ratio of the regenerated cellulosic fibers is higher than outer layer mixing ratio on a cross section of the spun yarn. The spun yarn can be manufactured by feeding a sliver including 15 mass% or more and less than 85 mass% of the natural cellulosic fibers and more than 15 mass% and 85 mass% or less of the regenerated cellulosic fibers in a draft zone, drafting the sliver, spinning the drafted sliver under a condition of nozzle pressure at 0.40 to 0.60 MPa, and winding up.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to spun yarns containing natural cellulosic fibers and regenerated cellulosic fibers, a method for producing the same, and fabrics containing the same. [Background technology]

[0002] In recent years, as the need for environmentally friendly materials has increased, biodegradable cellulose-based fibers have been widely used as clothing materials. For example, Patent Document 1 describes a spun yarn for clothing made by spinning 100% regenerated cellulose-based fibers made from bamboo using an air spinning frame. Patent Document 2 describes a high-twist air-jet spun yarn made of cotton fiber and regenerated cellulose. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-339650 A [Patent Document 2] Special Publication No. 2019-510893 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the fabric made using the spun yarn made of 100% regenerated cellulosic fiber described in Patent Document 1 has a problem of poor stiffness and stiffness, while the fabric made using the high-twist air-jet spun yarn described in Patent Document 2 tends to have a stiff feel.

[0005] In order to solve the above-mentioned problems in the conventional art, the present invention provides a spun yarn capable of producing a fabric having a soft feel while being firm, resilient and has good water absorption and quick-drying properties, a method for producing the same, and a fabric containing the same. [Means for solving the problem]

[0006] The present invention relates to a spun yarn containing 80% or more by mass of natural cellulosic fibers and regenerated cellulosic fibers, the spun yarn being composed of a group of untwisted fibers in an untwisted state and a group of wrapped fibers wrapped around the group of untwisted fibers, the spun yarn containing 15% or more by mass and less than 85% by mass of natural cellulosic fibers and more than 15% by mass and 85% or less by mass of regenerated cellulosic fibers, and in the cross section of the spun yarn, the mixing ratio of regenerated cellulosic fibers in the inner layer is higher than the mixing ratio of regenerated cellulosic fibers in the outer layer.

[0007] The present invention also relates to a method for producing a spun yarn containing 80% by mass or more of natural cellulosic fibers and regenerated cellulosic fibers, the method comprising the steps of preparing a sliver containing 15% by mass or more and less than 85% by mass of natural cellulosic fibers and more than 15% by mass and 85% by mass or less of regenerated cellulosic fibers in whirling air spinning, supplying the sliver to a draft zone and drafting it, and spinning and winding the sliver under conditions of a nozzle pressure of 0.40 to 0.60 MPa.

[0008] The present invention also relates to a fabric comprising said spun yarn. Effect of the Invention

[0009] The present invention can provide a spun yarn that can be used to obtain a fabric having a soft texture while being firm, stiff, and has good water absorption and quick drying properties, and a fabric having a soft texture while being firm, stiff, and has good water absorption and quick drying properties. Also, the present invention can produce a spun yarn that can be used to obtain a fabric having a soft texture while being firm, stiff, and has good water absorption and quick drying properties. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a side photograph (magnification: 100 times) of the spun yarn obtained in Example 1. [Diagram 2] Figure 2 is a cross-sectional photograph of the same spun yarn (magnification: 370x). [Diagram 3]FIG. 3 is an explanatory diagram of untwisted fibers, wrapped fibers, floating fibers, and fluffy fibers in a side photograph (magnification 100 times) of an example of spun yarn. [Figure 4] FIG. 4 is an explanatory diagram of the inner layer and the outer layer in the fiber cross section (magnification: 370 times) of the spun yarn (Example 2). [Diagram 5] FIG. 5 is an explanatory diagram of a method for measuring the diameter of a spun yarn. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The inventors of the present invention have conducted extensive research into improving the firmness, stiffness, and water absorption and quick-drying properties of a fabric made of spun yarn containing 80% by mass or more of cellulosic fibers. As a result, they have found that by making the spun yarn contain a predetermined ratio of natural cellulosic fibers and regenerated cellulosic fibers, forming the spun yarn into a structure composed of a group of untwisted fibers in an untwisted state and a group of wrapped fibers wrapped around the group of untwisted fibers, and by making the mixing ratio of regenerated cellulosic fibers in the inner layer of the cross section of the spun yarn higher than the mixing ratio of regenerated cellulosic fibers in the outer layer, the fabric made of the spun yarn has a soft feel while having good firmness, stiffness, and water absorption and quick-drying properties.

[0012] Specifically, by making the spun yarn contain natural cellulose fibers and regenerated cellulose fibers in a predetermined ratio and by making the spun yarn have a structure composed of a group of untwisted fibers in an untwisted state and a group of wrapped fibers wrapped around the group of untwisted fibers, it is possible to improve the firmness and stiffness of the fabric using the spun yarn while maintaining the soft feel. Also, by making the mixing ratio of regenerated cellulose fibers in the inner layer of the cross section of the spun yarn higher than the mixing ratio of regenerated cellulose fibers in the outer layer, that is, by distributing more regenerated cellulose fibers on the inside of the yarn, the regenerated cellulose fibers are less likely to get wet with a small amount of sweat, and the water absorption and quick drying properties of the fabric using the spun yarn are improved.

[0013] In this specification, when a numerical range is indicated by "-", the numerical range includes both end values ​​(upper and lower limits). For example, a numerical range of "A to B" is a range including both end values ​​A and B. In addition, when multiple numerical ranges are described in this specification, they include numerical ranges that appropriately combine the upper and lower limits of different numerical ranges.

[0014] The spun yarn (hereinafter, also referred to simply as yarn) is composed of a group of untwisted fibers (hereinafter, also referred to as untwisted fibers) in an untwisted state and a group of wrapped fibers (hereinafter, also referred to as wrapped fibers) wrapped around the group of untwisted fibers. Here, the untwisted state means a state in which the fibers inside (the center) of the yarn are parallel to the yarn axis in spun yarn obtained by air spinning such as Vortex (registered trademark) yarn. In addition, when observing the side of the yarn, a fiber that completely crosses the side of the yarn and is completely in contact with the side of the yarn is considered to be a wrapped fiber. A fiber that does not have a part in contact with the side of the yarn and cannot exert a wrapping force toward the center of the yarn cross section is not treated as a wrapped fiber. Among fibers that do not fall under either untwisted fibers or wrapped fibers, those with both ends in contact with the side of the yarn are called floating fibers, and those with one end separated from the side of the yarn are called fluff fibers. All fibers that do not fall under either wrapped fibers, floating fibers, or fluff fibers are considered to be untwisted fibers. Figure 3 shows an example of a spun yarn with non-twisted fibers, wrapped fibers, floating fibers, and fluffy fibers. By giving the spun yarn such a structure, the fiber convergence is improved, and the firmness, stiffness, and water absorption and quick-drying properties of the fabric made from the spun yarn are improved.

[0015] The porosity of the spun yarn is preferably 65% ​​or less, more preferably 60% or less, even more preferably 55% or less, and particularly preferably 50% or less. This allows the fibers to be densely packed, and the fixation of the untwisted fibers by the wrapped fibers is enhanced, resulting in good anti-pilling properties for the fabric containing the spun yarn. The lower limit of the porosity is not particularly limited, but from the viewpoint of a soft texture, it is preferably 20% or more, more preferably 30% or more, and even more preferably 40% or more. The porosity of the spun yarn can be measured as described in the Examples.

[0016] The spun yarn contains 80% by mass or more of natural cellulose fibers and regenerated cellulose fibers. This makes the spun yarn and the fabric using the same biodegradable and environmentally friendly. From the viewpoint of enhancing biodegradability, the spun yarn preferably contains 85% by mass or more of natural cellulose fibers and regenerated cellulose fibers, more preferably contains 90% by mass or more, and even more preferably contains 95% by mass or more, and is particularly preferably substantially composed of natural cellulose fibers and regenerated cellulose fibers.

[0017] The spun yarn contains 15% by mass or more and less than 85% by mass of natural cellulosic fibers. By containing 15% by mass or more of natural cellulosic fibers, it is possible to improve firmness and stiffness. By containing less than 85% by mass of natural cellulosic fibers, it is possible to obtain a soft texture. The spun yarn contains preferably 20 to 80% by mass of natural cellulosic fibers, more preferably 25 to 75% by mass, and even more preferably 30 to 70% by mass.

[0018] The natural cellulosic fibers are not particularly limited, and examples thereof include cotton, hemp, pulp, etc. From the viewpoint of firmness and stiffness, cotton is preferred.

[0019] The spun yarn contains more than 15% by mass and not more than 85% by mass of regenerated cellulose fibers. By containing more than 15% by mass of regenerated cellulose fibers, a soft texture can be imparted. By containing not more than 85% by mass of regenerated cellulose fibers, firmness, stiffness, and water absorption and quick drying properties are improved. The spun yarn contains preferably 20 to 80% by mass of regenerated cellulose fibers, more preferably 25 to 75% by mass, and even more preferably 30 to 70% by mass.

[0020] The regenerated cellulose fiber is not particularly limited, and examples thereof include viscose rayon (also simply called rayon), cupra, and solvent-spun cellulose fiber. From the viewpoint of texture, viscose rayon is preferred. As the viscose rayon, functional viscose rayon containing functional agents can be used. This allows various functionalities to be imparted to the spun yarn and the fabric using the same. From the viewpoint of washing durability, it is preferred to use functional viscose rayon containing functional agents inside the fiber. As such functional viscose rayon, for example, rayon with various functional agents kneaded therein manufactured by Daiwabo Rayon Co., Ltd. can be appropriately used.

[0021] In the cross section of the spun yarn, the mixing ratio of regenerated cellulose fiber in the inner layer is higher than that in the outer layer. This reduces the proportion of regenerated cellulose fiber on the surface that comes into contact with moisture such as sweat, improving water absorption and quick drying. In the cross section of the spun yarn, the mixing ratio of regenerated cellulose fiber in the inner layer is preferably 3 to 70% higher than the mixing ratio of regenerated cellulose fiber in the outer layer, more preferably 5 to 50%, and even more preferably 7 to 30% higher. In this specification, the inner layer and the outer layer in the cross section of the spun yarn are defined as follows. The spun yarn is embedded in epoxy and surface-finished with a microtome, and then an image of the yarn cross section is obtained with a scanning electron microscope. When a circle is drawn with the center of gravity of each fiber and the radius of the major axis of each fiber as the major axis, the fibers included in the area of ​​the cross section of any fiber are defined as the constituent fibers of one spun yarn. Next, a circle or ellipse with the smallest perimeter that circumscribes all the constituent fibers of the yarn is drawn, and this circle or ellipse is defined as the outer perimeter of the spun yarn. Next, a circle or ellipse with the same center as the outer perimeter circle or ellipse and with a diameter or long side that is half that of the outer perimeter circle or ellipse is drawn, and this circle or ellipse is defined as the inner perimeter of the cross section of the spun yarn. In this case, when the outer perimeter and the inner perimeter are ellipses, they are drawn so that their long and short sides overlap. The area between the outer perimeter and the inner perimeter is defined as the outer layer area of ​​the spun yarn. The area formed by the inner perimeter is defined as the inner layer area of ​​the spun yarn. The inner layer and outer layer blend ratios of regenerated cellulosic fibers in the cross section of the spun yarn are measured as described in the Examples.

[0022] The difference in single fiber fineness (T1-T2) between the single fiber fineness T1 of the natural cellulose fiber and the single fiber fineness T2 of the regenerated cellulose fiber is preferably 0.01 to 2.5 dtex, more preferably 0.05 to 2.0 dtex, and even more preferably 0.1 to 1.5 dtex, which tends to result in a structure in which the cross section of the spun yarn has a higher blend ratio of regenerated cellulose fiber in the inner layer than in the outer layer.

[0023] The natural cellulosic fibers are not particularly limited, but from the viewpoint of suitable use in clothing, for example, the single fiber fineness is preferably 0.4 to 5 dtex, more preferably 0.5 to 3.5 dtex, and even more preferably 0.6 to 2.5 dtex. In the case of cotton, the single fiber fineness is preferably 2.8 to 5.5 micronaire (1.1 to 2.2 dtex), and more preferably 3.5 to 4.9 micronaire (1.3 to 1.9 dtex).

[0024] The natural cellulose fibers are not particularly limited, but from the viewpoint of productivity in the spinning process, the fiber length is preferably 22 to 55 mm, more preferably 28 to 55 mm, and even more preferably 32 to 54 mm. In the case of cotton, the fiber length is preferably 22 to 45 mm, and more preferably 24 to 33 mm.

[0025] The regenerated cellulose fibers are not particularly limited, but from the viewpoint of suitable use in clothing, the single fiber fineness is preferably 0.4 to 5 dtex, more preferably 0.5 to 3.5 dtex, and even more preferably 0.6 to 2.5 dtex.

[0026] The regenerated cellulose fibers are not particularly limited, but from the viewpoint of productivity in the spinning process, the fiber length is preferably 24 to 55 mm, more preferably 28 to 55 mm, and even more preferably 32 to 54 mm.

[0027] The spun yarn may contain other fibers in addition to natural cellulose fibers and regenerated cellulose fibers. Examples of other fibers include, but are not limited to, polyolefin fibers, acrylic fibers, polyamide fibers, acetate fibers, ethylene vinyl alcohol fibers, urethane fibers, natural fibers other than natural cellulose fibers, and animal fibers. The other fibers may be fibers made of biodegradable raw materials, or may be fibers to which biodegradability has been imparted by kneading or post-processing. The spun yarn may contain 20% by mass or less, 10% by mass or less, or 5% by mass or less of other fibers as appropriate, depending on the application and purpose.

[0028] In the spun yarn, the other fibers are not particularly limited, but from the viewpoint of suitable use in clothing, for example, the single fiber fineness is preferably 0.4 to 5 dtex, more preferably 0.5 to 3.5 dtex, and even more preferably 0.6 to 2.5 dtex.

[0029] In the spun yarn, the other fibers are not particularly limited, but from the viewpoint of productivity of the spinning process, the fiber length is preferably 24 to 55 mm, more preferably 28 to 55 mm, and even more preferably 32 to 54 mm.

[0030] The count of the spun yarn is not particularly limited, but may be in the range of 5 to 70, preferably 10 to 60, and more preferably 15 to 50 in British cotton count.

[0031] The spun yarn is not particularly limited, but for example, from the viewpoint of further improving the anti-pilling property, the number of fluffs having a length of 1 mm or more is preferably 600 fluffs / 10 m or less, more preferably 300 fluffs / 10 m or less, and even more preferably 150 fluffs / 10 m or less. The number of fluffs having a length of 3 mm or more is preferably 40 fluffs / 10 m or less, more preferably 30 fluffs / 10 m or less, and even more preferably 20 fluffs / 10 m or less. The number of fluffs having a length of 5 mm or more is preferably 10 fluffs / 10 m or less, more preferably 5 fluffs / 10 m or less, and even more preferably 3 fluffs / 10 m or less. The number of fluffs of the spun yarn can be measured as described in the Examples.

[0032] The spinning method of the spun yarn may be air spinning and is not particularly limited, but from the viewpoint of improving the firmness and stiffness of the fabric and the water absorption and quick drying properties, it is preferable to produce the spun yarn by whirling air spinning. In the whirling air spinning, a sliver containing 15% by mass or more and less than 85% by mass of the natural cellulosic fiber and more than 15% by mass and 85% by mass or less of the regenerated cellulosic fiber is prepared in advance, the sliver is fed to a draft zone and drafted, and then spun and wound under a nozzle pressure of 0.40 to 0.60 MPa to obtain a spun yarn. The whirling air spinning is not particularly limited, but for example, a VORTEX spinning machine manufactured by Murata Machinery Co., Ltd. can be used.

[0033] In the whirling air spinning, when the nozzle pressure is 0.40 MPa or more, the spun yarn can be used to obtain a fabric with a firm and resilient texture. When the nozzle pressure is 0.60 MPa or less, the spun yarn can be used to obtain a fabric with a soft texture that is not too stiff. The nozzle pressure is preferably 0.42 to 0.55 MPa, and more preferably 0.45 to 0.53 MPa.

[0034] In the whirling air spinning, although not particularly limited, for example, from the viewpoints of increasing productivity and achieving both texture and anti-pilling properties, the spinning speed is preferably 250 to 450 m / min, more preferably 260 to 430 m / min, and even more preferably 280 to 410 m / min.

[0035] In the spinning machine used for the whirling air spinning, from the viewpoint of achieving both texture and anti-pilling properties, the spindle diameter (diameter of the spindle hole) is preferably 1.0 to 1.3 mm, and more preferably 1.1 to 1.3 mm.

[0036] In the present invention, the fabric includes the spun yarn described above. The fabric may be a knitted fabric or a woven fabric. From the viewpoint of enhancing biodegradability, the fabric preferably includes 50% by mass or more of the spun yarn, more preferably includes 75% by mass or more, even more preferably includes 85% by mass or more, even more preferably includes 95% by mass or more, and particularly preferably includes 100% by mass. The fabric may include, in addition to the spun yarn, other yarns, for example, other spun yarns and / or filament yarns, within a range that does not impair the effects of the present invention. The fabric may have a single layer structure or may include two or more layers.

[0037] In the case of knitted fabrics, it may be single-sided plain knit, or it may be a modified single-sided knit such as pique knit, mesh knit, or fleece knit, or it may be double-sided smooth knit, cardboard knit, or waffle knit. In the case of double-sided knitting, the spun yarn may be used for the surface layer and / or the back layer.

[0038] In the case of woven fabrics, they may be single or double weaves such as plain weave, twill weave, satin weave, etc.

[0039] The fabric may be subjected to scouring and bleaching. In addition, if necessary, the fabric may be subjected to dyeing or finishing after scouring and bleaching. The fabric may be subjected to water absorption treatment, SR (Soil release) treatment, antibacterial treatment, antistatic treatment, etc. at the same time as the dyeing or finishing.

[0040] The fabric is preferably subjected to a water-absorption softening treatment in order to enhance water-absorption quick-drying properties and softness. The water-absorption softening treatment can be carried out using a softener having water absorption properties, such as a water-absorbing silicone-based softener.

[0041] From the viewpoint of high water absorption and quick drying, the fabric preferably has an evaporation rate of 25% or more 20 minutes after the start of the test in a transpiration (II) test (based on BOKEN standard BQE A 028), more preferably 30% or more. Furthermore, from the viewpoint of moisture retention and the like, the fabric is not particularly limited, but preferably has an evaporation rate of 70% or less 20 minutes after the start of the test in a transpiration (II) test (based on BOKEN standard BQE A 028). The transpiration (II) test is a test for comprehensively evaluating both water absorption and quick drying, and the evaporation rate can be measured as described in the Examples.

[0042] From the viewpoint of high quick-drying property, the time from the start of the diffusible residual moisture content test until the diffusible residual moisture content reaches 10% or less is preferably 75 minutes or less, more preferably 70 minutes or less, and even more preferably 65 minutes or less. The diffusible residual moisture content test is a test for evaluating the drying property of a fabric that has absorbed water, and the diffusible residual moisture content can be measured as described in the Examples.

[0043] The fabric has a bending stiffness of 0.020 gf cm in a specified plain weave in order to provide excellent stiffness and stiffness. 3 / cm or more, and 0.025gf cm 3 / cm or more is preferable, and 0.035gf cm 3 From the viewpoint of wearing comfort, the fabric preferably has a bending stiffness of 0.080 gf cm 3 / cm or less, and 0.070gf cm 3 / cm or less is more preferable. In this specification, the bending stiffness can be measured as described in the Examples. Here, the "predetermined plain knit fabric" means a knit fabric produced so that the cover factor is 1.30 or more and 1.70 or less. In this specification, the cover factor is measured in accordance with JIS L 1096 8.8:2010.

[0044] From the viewpoint of enhancing heat dissipation, the fabric preferably has a heat retention rate of 20.0% or less, more preferably 15.0% or less, as measured by a dry contact method using Thermo Labo 2 manufactured by Kato Tech Co., Ltd.

[0045] When the fabric is a knitted fabric, for example, from the viewpoint of reducing stuffiness, the airflow resistance is preferably 0.200 kPa·s / m or less, and more preferably 0.180 kPa·s / m or less. Also, from the viewpoint of transparency, the fabric preferably has an airflow resistance of 0.005 kPa·s / m or more. A specific method for measuring the airflow resistance is as described in the Examples.

[0046] When the fabric is a knitted fabric, from the viewpoint of pilling resistance, the pilling resistance measured using an ICI type testing machine based on JIS L 1076:2012 Method A is preferably 3.5 or higher, more preferably 4 or higher, and even more preferably 4.5 or higher.

[0047] In the case of a knitted fabric, the thickness of the fabric is preferably 0.50 mm or more, more preferably 0.60 mm or more, from the viewpoint of heat retention, and is not particularly limited, but is preferably 4.0 mm or less, from the viewpoint of comfort when worn.

[0048] In the case of a knitted fabric, the fabric is preferably, for example, 450 g / m2 in terms of lightweight and other wearability. 2 It is preferable that the thickness is less than 400 g / m 2 More preferably, it is 300 g / m or less. 2 More preferably, it is 200 g / m or less. 2In addition, the fabric is not particularly limited, but from the viewpoint of transparency, it is particularly preferable that the fabric has a basis weight of 50 g / m 2 More preferably, it is equal to or greater than this.

[0049] The fabric can be used for clothing, materials, etc. Examples of clothing include sports clothing, home wear, underwear, outerwear, etc. Examples of sports clothing include outdoor shirts, training wear, sweatshirts, pants, polo shirts, etc. Examples of underwear include T-shirts, briefs, trunks, camisoles, shorts, etc. Examples of materials include linings, shoe materials, supporters, socks, carpets, bedding, etc. EXAMPLES

[0050] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0051] The measurement and evaluation methods used in the examples and comparative examples are as follows.

[0052] (1) Official moisture regain JIS L 0105:2020 General rules for physical testing methods of textile products 4.1 Official moisture regain Table 1 - Official moisture regain of fibers was referenced. (2) Single fiber fineness Measurements were taken in accordance with JIS L 1015:2010. (3) Specific gravity of fiber "Density of Fibers", Seizo Tsuyoshi, Textile Engineering, Vol. 21, No. 7, 1968, pp. 458-463. (4) Porosity In the side image of the yarn, fibers that completely cross the side of the yarn and are completely in contact with the side of the yarn were considered to be wrapped fibers. Fibers that do not have part of their surface in contact with the side of the yarn and cannot exert a wrapping force toward the center of the yarn cross section were not treated as wrapped fibers. Among fibers that do not fall into either the untwisted fibers at the center of the yarn or the wrapped fibers, those with both ends in contact with the side of the yarn were considered to be floating fibers, and those with one end separated from the side of the yarn were considered to be fluffy fibers. All fibers that do not fall into either the wrapped, floating, or fluffy fibers were considered to be untwisted fibers. In addition, the fiber that is in contact with the adjacent fiber in the center direction of the yarn cross section and is located on the outermost side in the yarn cross section is defined as the outermost fiber. The outermost fiber may be a wrapped fiber or a non-twisted fiber. If either end or part of a fiber is separated from the adjacent fiber in the cross-sectional direction of the yarn, it is excluded from the outermost fiber. Figure 3 shows the non-twisted fiber, wrapped fiber, floating fiber, and fluffy fiber in an example spun yarn. (I) Calculation of spun yarn diameter from side observation of yarn The side of the yarn was photographed under no tension using a KEYENCE electron microscope VE-9800 (magnifications of 40 to 100 times). For example, as shown in Figure 5, a tangent line Lt was drawn in the longitudinal direction of the yarn to the outermost fiber of the yarn at any point, and a perpendicular line Ls to the tangent line Lt was drawn perpendicular to the central axis (longitudinal direction) of the yarn. The intersection point of the perpendicular line Lt and the outermost fiber constituting the yarn was designated as C. Furthermore, the intersection point of the outermost fiber on the opposite side of the intersection point C across the perpendicular line Lt and the central axis of the yarn was designated as D. The distance between CD was measured and used as the yarn diameter. Five images were taken at different points for one sample. The yarn diameter at five points was calculated for each image, and used as the representative value for the images. The average value of the five images was calculated and used as the representative value for the yarn sample. (II) Calculation of apparent density of spun yarn The weight per unit length was calculated from the correct count (JIS L 1095:2010 9.4.1 Correct tex and count). The apparent density of the yarn was defined by dividing the weight per unit length by the volume calculated by approximating the cross section of the yarn to a circle using the spun yarn diameter measured in (I). The smaller the apparent density, the greater the bulk per unit length of the yarn. (III) Porosity calculation method The volume Vm of a cylinder that has the same specific gravity as the fiber material constituting an arbitrary thread and weighs the same as that thread was calculated. Furthermore, the thread diameter measured in (I) was used to approximate the cross section of the thread to a circle to calculate the thread volume Vy. Dividing Vm by Vy and multiplying the result by 100 gave the ratio of the volume of the fiber in the thread. Subtracting this from 100 gave the porosity, which is the ratio of air in the thread. Note that the fiber specific gravity described in JIS L 1096:2010 8.11 Apparent specific gravity and pore volume ratio was used for the calculation. (5) Inner layer and outer layer yarn mix ratio The cross section of the yarn was embedded in epoxy to maintain the cross-sectional shape, and then surfaced with a glass knife using a microtome (Leica EM UC6). The image was taken at 370x magnification using a scanning electron microscope (Keyence VE-9800 electron microscope) to obtain an image of the cross section of the yarn. When the longest line segment formed by the intersection of the line passing through the center of gravity of the cross section of each fiber and the outer periphery of the cross section is taken as the long axis, and a circle is drawn with the center of gravity of each fiber as the center and the radius is the length of the long axis of each fiber, the fibers contained in the area formed by any fiber cross section are defined as the constituent fibers of one spun yarn. Next, as shown in Figure 4, a circle or ellipse with the smallest perimeter that circumscribes all the constituent fibers of the yarn is drawn inside, and the circle or ellipse is taken as the outer periphery of the yarn. Next, a circle or ellipse with the same center as the circle or ellipse that forms the outer periphery and a diameter or long side is half is drawn, and the circle or ellipse is taken as the inner periphery of the cross section of the yarn. In this case, when the outer and inner circumferences were ellipses, the long and short sides were drawn so that they overlapped. The area between the outer and inner circumferences was taken as the outer layer area of ​​the yarn. The area formed by the inner circumference was taken as the inner layer area of ​​the yarn. The blending ratios of the outer and inner layer areas were calculated from the number of fibers and fiber fineness contained in the outer and inner layer areas, and were taken as the outer layer blending ratio and the inner layer blending ratio, respectively. Fibers that exist on the boundary line were considered to exist in the area where the center of gravity is located, and the blending ratio was calculated. Three images of the yarn cross section at different points were taken for one sample, and the average blending ratio of the three images was calculated and used as the representative value for that yarn sample. (6) Number of fluff Measurement was performed in accordance with JIS L 1095:2010 9.22.2 Method B. An F-INDEX TESTER (Shikishima Boseki Co., Ltd.) was used as the fluff tester, and the test conditions were yarn speed 30 m / min, test length 10 m, and N=30. (7) British cotton count The measurements were made in accordance with the cotton count measurement method for measuring correct tex and count of general spun yarn in JIS L 1095:2010 9.4.1. (8) Metsuke Measurements were performed in accordance with JIS L 1096:2010. (9) Cover factor Measurements were taken in accordance with JIS L 1096 8.8:2010. (10) Bending rigidity The bending stiffness was measured using a pure bending tester KES-FB2-A manufactured by Kato Tech Co., Ltd. Specifically, the fabric was oriented in the course direction with a maximum curvature of ±2.5 cm. -1 , bending speed 0.5 cm -1 The bending stiffness was measured when the specimen was bent at 20°C and 65% RH. Measured. (11) Water absorption and quick drying properties The transpiration rate after 20 minutes was determined according to the transpiration (II) test (BOKEN standard BQE A 028) of the General Incorporated Foundation Boken Quality Evaluation Organization. The Boken general product standard is 30% or more. The transpiration rate was measured and calculated specifically using the following method. (a) The mass (W) of the test piece with a diameter of approximately 9 cm and the petri dish was measured. (b) 0.1 mL of water was dropped onto a petri dish, the test piece was placed on top of it, and the total mass (W0) was measured. (c) The specimen was left under standard conditions (20°C, 65% RH) and the total mass (Wt) was measured at each specified time, and the evaporation rate (%) after 20 minutes was calculated. Transpiration rate (%)={(W0-Wt) / (W0-W)}×100 (12) Diffusible residual moisture content Based on the diffusible residual moisture content test by the Boken Quality Evaluation Institute, the standard value was determined as the time required for the residual moisture content to reach 10%. The general quality standard for 100% cellulose fabrics is that the residual moisture content must reach 10% in 75 minutes or less. The residual moisture content and standard value were measured and calculated specifically using the following method. (a) 0.6 ml of water was dropped onto a 10 cm square test piece (mass: W1) and the total mass (W01) was measured. (b) The test piece was left hanging in an environment of 20°C and 65% RH, and the mass (Wt1) was measured at specified time intervals to calculate the residual moisture content. Residual moisture percentage (%)={(W01-Wt1) / (W01-W1)}×100 (c) The drying time required for the residual moisture content to fall below 10% was used as the standard value. (13)q-max The q-max was measured using a KES-F7 (Thermo Lab) manufactured by Kato Tech Co., Ltd. The measurement environment was 20°C and 65% RH. The measurement method followed the method specified by the manufacturer. The higher the q-max value, the higher the sensation of coolness to the touch. (14) Heat retention rate The heat retention rate was measured by the dry contact method using Thermo Lab 2 manufactured by Kato Tech Co., Ltd., and the heat retention was evaluated. Specifically, the heat retention rate was calculated by measuring the amount of heat (power consumption) radiated through a test piece (20 x 20 cm) from a hot plate set at an ambient temperature +10°C at a constant air flow (30 cm / s). The higher the heat retention rate, the higher the heat retention. (15) Airflow resistance Measurements were taken using a KES-F8 air permeability tester manufactured by Kato Tech Co., Ltd. A constant flow rate of air was sent to the sample by the piston movement of a plunger / cylinder, and the sample was released into the atmosphere and then sucked in. The air permeability resistance was calculated from the pressure during release and suction. Measurement conditions were SENS: M, SPEED: 0.2. (16) Anti-pilling properties Based on JIS L 1076:2012 Method A, a pilling test was conducted using an ICI type testing machine to confirm the degree of pilling. (17) Spectral transmittance The spectral transmittance was measured using an ultraviolet / visible / near infrared spectrophotometer (Shimadzu Corporation, UV-3600 / MPC-3100). The average spectral transmittance in the wavelength range of 280-400 nm (hereinafter also referred to as ultraviolet transmittance) and the average spectral transmittance in the wavelength range of 780-1000 nm (hereinafter also referred to as near-infrared transmittance) were calculated. The lower the ultraviolet transmittance, the higher the ultraviolet blocking effect, and the lower the near-infrared transmittance, the higher the heat blocking effect.

[0053] Example 1 (Yarn manufacturing) A sliver obtained by blending 50 parts by mass of heat-shielding rayon fiber (manufactured by Daiwabo Rayon Co., Ltd., product name "Rayshield", single fiber fineness 1.10 dtex, fiber length 38 mm, official moisture content 11.0%) with 50 parts by mass of cotton fiber (Upland cotton, single fiber fineness 1.63 dtex, average fiber length 27.0 mm, official moisture content 8.5%) was fed to the draft zone of a VORTEX spinning machine (manufactured by Murata Machinery Co., Ltd., model number "VORTEX 861") and drafted, then spun under conditions of a nozzle pressure of 0.50 MPa and a spinning speed of 300 m / min, and wound up to produce a spun yarn (MVS yarn) with a British cotton count of 20s. The spindle diameter was 1.1 mm. (Fabric manufacturing) The spun yarn obtained above was used to knit a plain knit fabric (cover factor 1.56) using a 30-inch 24-gauge circular knitting machine. The knit fabric obtained was scouring and bleaching using 4 g / L of hydrogen peroxide (27.5%), 3 g / L of soda ash, and 1.5 g / L of scouring agent at 95°C for 40 minutes, and then finishing was performed using a water-absorbing silicone softener (manufactured by Suzhou Chengda Biotechnology Co., Ltd., KSCC) by the Pad-dry method to produce a fabric.

[0054] Example 2 (Yarn manufacturing) A sliver obtained by blending 30 parts by mass of heat-shielding rayon fiber (manufactured by Daiwabo Rayon Co., Ltd., product name "Rayshield", single fiber fineness 1.10 dtex, fiber length 38 mm, official moisture regain 11.0%) and 70 parts by mass of cotton fiber (Upland cotton, single fiber fineness 1.63 dtex, average fiber length 27.0 mm, official moisture regain 8.5%) was used, and a spun yarn (MVS yarn) with a British cotton count of 20s was produced in the same manner as in Example 1. (Fabric manufacturing) A plain stitch knit (cover factor 1.59) was knitted in the same manner as in Example 1, except that the spun yarn obtained above was used, to produce a fabric.

[0055] Comparative Example 1 (Manufacturing of yarn) 50 parts by mass of heat-shielding rayon fiber (manufactured by Daiwabo Rayon Co., Ltd., product name "Rayshield", single fiber fineness 1.10 dtex, fiber length 38 mm, official moisture content 11.0%) and 50 parts by mass of cotton fiber (Upland cotton, single fiber fineness 1.63 dtex, average fiber length 27.0 mm, official moisture content 8.5%) were fed in sequence to the cotton blending process, carding process, drawing process, and roving process to obtain a roving yarn of 120 grains / 12 yds. Next, using two of the obtained roving yarns, a 31-fold draft was given to a ring spinning machine equipped with a compact spinning system, and the fibers were converged by sucking air in the direction of the roving yarn's travel, and then twisted with a twist factor of 3.7 to produce a spun yarn (ring yarn) with a British cotton count of 26s. (Fabric manufacturing) The spun yarn obtained above was used to knit a plain knitted fabric (cover factor 1.47) using a 34-inch 24-gauge circular knitting machine. The knitted fabric obtained was scouring bleached and UV-treated at 95°C for 40 minutes using 4g / L hydrogen peroxide (27.5%), 3g / L soda ash, 1.5g / L scouring agent, and 1.0g / L UV processing agent (Huntsman, UV-SUN CEL LIQ), and then finished by the Pad-dry method using a water-absorbing silicone softener (Suzhou Chengda Biotechnology Co., Ltd., KSCC) to produce a fabric.

[0056] Comparative Example 2 (Yarn manufacturing) 100 parts by mass of cotton fiber (Upland cotton, single fiber fineness 1.63 dtex, average fiber length 27.0 mm, official moisture regain 8.5%) was fed in the following order: mixed-battery process, carding process, drawing process, and roving process to obtain a roving yarn of 120 grains / 12 yds. Next, two of the obtained roving yarns were used and given a draft of 31 times in a ring spinning machine, and twisted with a twist factor of 3.7 to produce a spun yarn (ring yarn) of British cotton count 26s. (Fabric manufacturing) The spun yarn obtained above was used to knit a plain knitted fabric (cover factor 1.52) using a 34-inch 24-gauge circular knitting machine. The knitted fabric obtained was scouring and bleached using 6 g / L of hydrogen peroxide (27.5%), 1 g / L of caustic soda, and 1.5 g / L of scouring agent at 98°C for 40 minutes, and then finished using a water-absorbing silicone softener (manufactured by Suzhou Chengda Biotechnology Co., Ltd., KSCC) by the Pad-dry method to produce a fabric.

[0057] Comparative Example 3 (Yarn manufacturing) 100 parts by mass of cotton fiber (Upland cotton, single fiber fineness 1.63 dtex, average fiber length 27.0 mm, official moisture regain 8.5%) was fed in the mixed cotton process, carding process, drawing process, and roving process in order to obtain a roving yarn of 90 grains / 12 yds. Next, two of the obtained roving yarns were used in a ring spinning machine equipped with a compact spinning system, and a 36-fold draft was applied. The fibers were converged by sucking air in the direction of the roving yarn's movement, and then twisted with a twist factor of 3.7 to produce a spun yarn (ring yarn) with a British cotton count of 40s. (Fabric manufacturing) The spun yarn obtained above was aligned and knitted into a plain weave knitted fabric (cover factor 1.44) using a 34-inch 24-gauge circular knitting machine. The knitted fabric obtained was scoured and bleached using 6 g / L of hydrogen peroxide (27.5%), 1 g / L of caustic soda, and 1.5 g / L of scouring agent at 98°C for 40 minutes, and then finished using a cationic softener by the Pad-dry method to produce a fabric.

[0058] In the examples and comparative examples, the inner layer blending ratio and outer layer blending ratio, fluff count, and porosity of the spun yarn were measured as described above, and the results are shown in the following Table 1. In the examples and comparative examples, the fabric basis weight, transmittance, heat retention, q-max, water absorption and quick-drying property, quick-drying property, air resistance, bending rigidity, and anti-pilling property were measured and evaluated as described above, and the results are shown in the following Table 1. Table 1 also shows the spinning conditions of the spun yarn, the fabric basis weight, course density, and wale density.

[0059] [Table 1]

[0060] Fig. 1 shows a side photograph (magnification 100x) of the spun yarn obtained in Example 1, and Fig. 2 shows a cross-sectional photograph (magnification 370x) of the same spun yarn. As can be seen from Figs. 1 and 2, the spun yarn produced by vortex air spinning in this example is composed of a group of untwisted fibers in an internal untwisted state and a group of wrapped fibers wrapped around the group of untwisted fibers.

[0061] As can be seen from the results in Table 1 above, the fabric using the heat-shielding rayon fiber of the Example and the MVS yarn made of cotton had the same bending rigidity as the fabric of Comparative Example 3 using 100% cotton ring yarn, and had good firmness and stiffness. Furthermore, the fabric using the heat-shielding rayon fiber of the Example and the spun yarn (MVS yarn) made of cotton had an evaporation rate of 30% or more 20 minutes after the start of the evaporation (II) test (based on Boken standard BQE A 028), and had good water absorption and quick-drying properties. Furthermore, the fabric using the heat-shielding rayon fiber of the Example and the spun yarn (MVS yarn) made of cotton had a soft texture. Furthermore, the fabric using the heat-shielding rayon fiber of the Example and the MVS yarn made of cotton had a lower near-infrared transmittance and a superior heat-shielding effect than the fabric using the 100% cotton ring yarn of Comparative Example 3. Furthermore, the fabric using the heat-shielding rayon fiber of the Example and the MVS yarn made of cotton had a lower ultraviolet transmittance and a superior ultraviolet blocking effect than the fabric using the 100% cotton ring yarn of Comparative Example 2.

Claims

1. A spun yarn containing 80% by mass or more of natural cellulose fibers and regenerated cellulose fibers, wherein the spun yarn is composed of a group of non-twisted fibers in a non-twisted state and a group of winding fibers wound around the periphery of the group of non-twisted fibers, the spun yarn contains 15% by mass or more and less than 85% by mass of natural cellulose fibers and more than 15% by mass and 85% by mass or less of regenerated cellulose fibers, and in the cross-section of the spun yarn, the mixing ratio of regenerated cellulose fibers in the inner layer is higher than the mixing ratio of regenerated cellulose fibers in the outer layer.

2. The single fiber fineness T of the natural cellulose fiber 1 and the single fiber fineness T of the regenerated cellulose fiber 2 The difference in single fiber fineness (T 1 - T 2 ) is 0.01 to 2.5 dtex. The spun yarn according to claim 1.

3. In the cross-section of the spun yarn, the mixing ratio of regenerated cellulose fibers in the inner layer is 3 to 70% higher than the mixing ratio of regenerated cellulose fibers in the outer layer. The spun yarn according to claim 1.

4. The natural cellulose fiber is cotton. The spun yarn according to claim 1.

5. The regenerated cellulose fiber is a viscose rayon fiber. The spun yarn according to claim 1.

6. A method for manufacturing a spun yarn containing 80% by mass or more of natural cellulose fibers and regenerated cellulose fibers, in vortex air spinning, a step of preparing a sliver containing 15% by mass or more and less than 85% by mass of the natural cellulose fiber and more than 15% by mass and 85% by mass or less of the regenerated cellulose fiber, a step of supplying the sliver to a drafting zone and drafting it, and a step of spinning and winding under the condition that the nozzle pressure is 0.40 to 0.60 MPa. A method for manufacturing a spun yarn.

7. The method for manufacturing a spun yarn according to claim 6, wherein the spinning speed is 250 to 450 m / min.

8. The method for manufacturing a spun yarn according to claim 6, wherein the spindle diameter is 1.0 to 1.3 mm.

9. A fabric comprising the spun yarn according to any one of claims 1 to 5.

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