Spun yarn and method for manufacturing spun yarn

Abstract

This product provides fine spun yarn with excellent appearance quality, including recycled cotton. [Solution] A spun yarn containing cotton, wherein the effective fiber length of the cotton measured by Method A of JIS-L1019 7.2.1 is 21 mm or more and 28 mm or less, the short fiber content is 25% or more and 45% or less, the English cotton count is 5 count or more and 50 count or less, and the number of filamentous slabs is 1 (slab / 10,000m) or more and 35 (slab / 10,000m) or less.

Description

Technical Field

[0001] The present invention relates to a spun yarn and a method for producing the spun yarn. Background Art

[0002] In recent years, interest in recycling textile products has been increasing. For example, Patent Document 1 discloses a wiping body configured using recycled cotton-containing cotton fibers obtained by blending raw cotton fibers and recycled cotton fibers, wherein the recycled cotton fibers are produced by reprocessing waste cotton fibers with a garnett machine. Prior Art Documents Patent Documents

[0003] Patent Document 1 Japanese Unexamined Patent Application Publication No. 2019-165856 Summary of Invention Problems to be Solved by the Invention

[0004] The wiping body of Patent Document 1 is mainly for mops, and uses a thick yarn of approximately 1.3 count. The present inventors have found that when recycled cotton is spun to manufacture clothing articles and the like from finer spun yarns, a large number of old yarns that have not been sufficiently opened are mixed into the spun yarn. Such old yarns protrude from the main body of the spun yarn and impair the aesthetic appearance of the spun yarn, and are particularly noticeable in fine spun yarns. The present invention has been made in view of the above circumstances, and an object thereof is to provide a fine spun yarn containing recycled cotton and having excellent appearance quality. Another object is to provide a method that facilitates producing a fine spun yarn containing recycled cotton and having excellent appearance quality. Means for Solving the Problems

[0005] The spun yarn according to the embodiment of the present invention is as described in [1] below, and the method for producing a spun yarn according to the embodiment is as described in [7] below. [1] A spun yarn, which is comprising cotton, The effective fiber length of the cotton, as measured by Method A of JIS-L1019 7.2.1, is 21 mm or more and 28 mm or less, and the short fiber content is 25% or more and 45% or less. English cotton count is 5 count or higher and 50 count or lower, and A spun yarn having a number of filamentous slabs of 1 or more (slabs / 10,000m) and 35 or less (slabs / 10,000m). [7] A process of cutting cotton yarn, cotton textile products, or both, at intervals of 30 mm or more and 45 mm or less, and A method for producing spun yarn, comprising the step of using a high-speed fluid to defibrate and obtain a group of fibers having an effective fiber length of 24 mm or more and 29 mm or less, as measured by Method A of JIS-L1019 7.2.1.

[0006] As a result of the inventors' investigation, they found that by cutting a cotton-containing yarn or a cotton-containing textile product at the predetermined intervals as described in [7] above, and defibrating it with a high-speed fluid, a group of fibers with an effective fiber length of 24 mm or more and 29 mm or less can be obtained. Furthermore, they found that when such a group of fibers is used as raw material to form a fine spun yarn with an English cotton count of 5 to 50 as described in [1] above, a spun yarn is obtained that has a long effective fiber length as a recycled yarn, a low short fiber content, and a small number of filamentous slubs caused by the sticking out of old yarn, etc. Thus, according to the present invention, it is possible to provide a fine spun yarn containing recycled cotton with excellent appearance quality. Furthermore, it was found that using the above group of fibers makes it less likely for the yarn to break during spinning. This makes it possible to provide a method for easily producing a fine spun yarn containing recycled cotton with excellent appearance quality. The spun yarn according to the embodiment is preferably one of the following [2] to [6]. [2] The spun yarn described in [1], which is a ring-spun yarn. [3] A spun yarn as described in [1] or [2], having a Worcester yarn unevenness (U%) of 5.0% or more and 30% or less. [4] The spun yarn described in [3], wherein the A value calculated by the following formula (1) is 0.20 or greater and 3.0 or less. A = A1 / A2 ····(1) [In the formula, A1 is the Worcester yarn unevenness (U%), and A2 is the English cotton count (count).] [5] A spun yarn as described in any one of the items [1] to [4], wherein the number of 5 mm or larger fuzzy fibers is 10 (fibers / 10m) or more and 50 (fibers / 10m) or less. [6] The spun yarn described in [5], wherein the B value calculated by the following formula (2) is 0.2 or greater and 1.6 or less. B = B1 / B2 ... (2) [In the formula, B1 is the number of fibers 5 mm or longer (fibers / 10 m), and B2 is the short fiber content (%).] [Effects of the Invention]

[0007] The above configuration makes it possible to provide a fine spun yarn containing recycled cotton with excellent appearance quality. Furthermore, it is possible to provide a method that facilitates the production of a fine spun yarn containing recycled cotton with excellent appearance quality. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is an example of a photograph taken when the slab of spun yarn from the embodiment was unraveled to confirm that it was a filamentous slab. [Figure 2] Figure 2 is another example of a photograph taken when the slab of the spun yarn of the embodiment was unraveled to confirm that it was a filamentous slab. [Modes for carrying out the invention]

[0009] The spun yarn according to the embodiment is a spun yarn containing cotton, wherein the effective fiber length of the cotton measured by Method A of JIS-L1019 7.2.1 is 21 mm or more and 28 mm or less, the short fiber content is 25% or more and 45% or less, the English cotton count is 5 count or more and 50 count or less, and the number of filamentous slabs is 1 (slab / 10,000m) or more and 35 (slab / 10,000m) or less.

[0010] The method for manufacturing spun yarn according to the embodiment includes the steps of cutting a yarn containing cotton, a textile product containing cotton, or both thereof at intervals of 30 mm or more and 45 mm or less, and defibrating using a high-speed fluid to obtain a group of fibers having an effective fiber length of 24 mm or more and 29 mm or less as measured by Method A of JIS-L1019 7.2.1.

[0011] As a result of the inventors' investigations, it was found that by cutting cotton-containing yarn or cotton-containing textile products at the predetermined intervals described above and defibrating them with a high-speed fluid, a group of fibers with an effective fiber length of 24 mm or more and 29 mm or less can be obtained. Furthermore, it was found that when such a group of fibers is used as raw material to form a fine spun yarn with an English cotton count of 5 to 50 as described above, a spun yarn is obtained that has a long effective fiber length, a low short fiber content, and a small number of filamentous slubs caused by the protrusion of old yarn, etc., as a recycled yarn. Thus, according to the present invention, it is possible to provide a fine spun yarn containing recycled cotton with excellent appearance quality. Furthermore, it was found that using the above group of fibers makes it less likely for the yarn to break during spinning. This makes it possible to provide a method for easily producing a fine spun yarn containing recycled cotton with excellent appearance quality. The following describes in detail the spun yarn according to the embodiment and the method for producing it.

[0012] The spun yarn of this embodiment contains cotton. Preferably, the cotton contains recycled cotton. This can contribute to the effective use of resources. The cotton may contain both recycled cotton and virgin cotton. This can improve the durability of the spun yarn. Virgin cotton is unused cotton, which is cotton supplied to the spinning process for the first time. Recycled cotton is made by processing used textile products such as clothing, yarn, scraps, cutting waste, off-spec products, defective yarn, leftover yarn, defective fiber bundles, etc., generated in the spinning process, fabric manufacturing process, sewing process, etc., and returning them to a cotton-like state. The cotton may also contain cotton-like waste generated in the spinning process, such as combed noil generated in the combing process.

[0013] The spun yarn preferably contains 50% by mass or more and 100% by mass or less of recycled cotton. A recycled cotton content of 50% by mass or more contributes even more to the effective use of resources. Therefore, it is more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 95% by mass or more. On the other hand, the recycled cotton content may be 99% by mass or less, 95% by mass or less, 90% by mass or less, or 80% by mass or less. If the spun yarn contains waste cotton, the waste cotton content is preferably 1% by mass or more and 10% by mass or less.

[0014] When spun yarn contains recycled cotton and virgin cotton, the total content of these is preferably 50% by mass or more and 100% by mass or less. A content of 50% by mass or more contributes to the effective utilization of resources. Therefore, it is more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 95% by mass or more. On the other hand, the total content of recycled cotton and virgin cotton may be 99% by mass or less, 95% by mass or less, 90% by mass or less, or 80% by mass or less. In this case, the content of virgin cotton per 100 parts by mass of recycled cotton is preferably 100 parts by mass or less, more preferably 75 parts by mass or less, and even more preferably 50 parts by mass or less. On the other hand, the content of virgin cotton per 100 parts by mass of recycled cotton may be 10 parts by mass or more, 20 parts by mass or more, or 30 parts by mass or more.

[0015] The spun yarn may contain fibers other than cotton. Examples of other fibers include synthetic fibers such as polyester; regenerated fibers such as rayon and lyocell; and natural fibers other than cotton such as hemp. When the spun yarn contains other fibers, the content of other fibers may be less than 50% by mass, 40% by mass or less, or 30% by mass or less, per 100% by mass of the spun yarn. On the other hand, the content of other fibers may be 1% by mass or more, 5% by mass or more, 10% by mass or more, or 20% by mass or more.

[0016] The effective fiber length of cotton measured by Method A in JIS-L1019 7.2.1 for the spun yarn is 21 mm or more and 28 mm or less. When the effective fiber length is 21 mm or more, the strength and durability of the yarn are improved, and the quality of the woven fabric is stabilized. Therefore, the effective fiber length is preferably 22 mm or more, more preferably 23 mm or more. On the other hand, when the effective fiber length is 28 mm or less, the soft handfeel and flexibility tend to be improved.

[0017] The short fiber content of cotton measured by Method A in JIS-L1019 7.2.1 for the spun yarn is 25% or more and 45% or less. When the short fiber content is 45% or less, the strength and durability of the yarn are improved. Therefore, the short fiber content is preferably 40% or less. On the other hand, when the short fiber content is 25% or more, the soft handfeel and flexibility tend to be improved. Therefore, the short fiber content may be 26% or more, or 28% or more.

[0018] The English cotton count of the spun yarn is 5 or more and 50 or less. When the English cotton count is 5 or more, the spun yarn is easy to use for manufacturing apparel products such as woven fabrics and knitted fabrics. Therefore, the English cotton count is preferably 6 or more, more preferably 10 or more, and further preferably 15 or more. On the other hand, when the English cotton count is 50 or less, the strength of the yarn is improved. Therefore, the English cotton count is preferably 45 or less, more preferably 40 or less. The English cotton count can be measured by the method described in the Examples below. The spun yarn may be any of a single yarn, a two-ply yarn, or a three-ply twisted yarn, and in the case of a two-ply yarn or a three-ply twisted yarn, the above English cotton count is the count as the total fineness.

[0019] The number of filamentous slabs in the spun yarn is between 1 (slab / 10,000m) and 35 (slab / 10,000m). Having 35 (slabs / 10,000m) or fewer filamentous slabs improves the appearance quality of the spun yarn. Furthermore, it is believed that the durability of the spun yarn is also improved. Therefore, the number of filamentous slabs is preferably 30 (slabs / 10,000m) or less, more preferably 25 (slabs / 10,000m) or less, even more preferably 20 (slabs / 10,000m) or less, and even more preferably 10 (slabs / 10,000m) or less. On the other hand, since it is usually difficult to have 0 (slabs / 10,000m) filamentous slabs in recycled spun yarn, the number of filamentous slabs is 1 (slab / 10,000m) or more, and may be 2 (slabs / 10,000m) or more.

[0020] A filamentous slub is a thickened knot (slub) in spun yarn, which is thickened due to the presence of twisted filamentous fiber waste. Figures 1 and 2 show filamentous slubs that have been unraveled to expose the twisted filamentous fiber waste. In recycled spun yarn, filamentous slubs are mainly bundles of fibers that were not completely defibrated after the old yarn was cut, so it can be seen that the twist of the old yarn remains in the filamentous fiber waste. Specifically, filamentous slubs can be measured by the method described in the examples below, and large slubs measured by the testing machine described below degrade the appearance quality. In particular, because filamentous slubs are long, they float above the surface of the spun yarn, impairing the beautiful appearance, and they cause streaky irregularities on the fabric surface, resulting in a poor feel and significantly reducing the appearance quality and texture. Furthermore, the testing machine described later also detects slabs caused by foreign matter or fiber clumps mixed in during spinning, as well as dust adhering to the spun yarn, as slabs. In such a testing machine, the number of slabs that are not filamentous slabs is subtracted from the total number of slabs detected by the testing machine to determine the number of filamentous slabs (slabs / 10,000m).

[0021] The spun yarn is preferably ring-spun yarn. Ring-spun yarn is a spun yarn formed by the ring spinning method and tends to reduce yarn unevenness and fluffiness. In addition, the spun yarn may be open-end spun yarn, knot-spun yarn, etc. Knot-spun yarn can be produced using, for example, a vortex spinner manufactured by Murata Machinery, Ltd.

[0022] The spun yarn preferably has a Worcester yarn unevenness (U%) of 5.0% or more and 30% or less. A Worcester yarn unevenness of 30% or less further improves the appearance quality of the spun yarn. Woven and knitted fabrics made from such spun yarn will be of superior quality. For this reason, it is more preferably 25% or less, even more preferably 20% or less, and even more preferably 15% or less. On the other hand, a Worcester yarn unevenness of 5.0% or more makes it easier to obtain yarn quality close to that of spun yarn made from virgin fibers. For this reason, it is more preferably 9.5% or more, and even more preferably 10.0% or more. The Worcester yarn unevenness can be measured by the method described in the examples below.

[0023] The spun yarn is preferably of a value of A calculated by the following formula (1) that is between 0.20 and 3.0. A = A1 / A2 ····(1) [In the formula, A1 is Worcester yarn slub (U%), and A2 is English cotton count (count).] As spun yarn tends to show less visible unevenness as the yarn thickness increases, the A value in formula (1) is a value corrected by dividing the Worcester yarn unevenness (U%) by the English cotton count. The lower the A value, the better the uniformity of the visible thickness of the spun yarn. Therefore, the A value is preferably 3.0 or less, more preferably 2.0 or less, even more preferably 1.5 or less, and even more preferably 1.2 or less. On the other hand, an A value of 0.20 or more tends to improve softness and flexibility. Therefore, it is more preferably 0.30 or more. The A value can be measured by the method described in the examples below.

[0024] The spun yarn preferably has 10 to 50 fluffs (5 mm or larger) per 10m. Having 50 fluffs per 10m or less makes it easier to produce beautiful, high-quality clothing and improves abrasion resistance. Therefore, it is more preferable to have 40 fluffs per 10m or less, and even more preferable to have 35 fluffs per 10m or less. On the other hand, having 10 or more fluffs per 10m makes it easier to maintain the appearance and texture characteristic of spun yarn. Therefore, it is more preferable to have 15 fluffs per 10m or more, and even more preferable to have 20 fluffs per 10m or more. The number of fluffs (5 mm or larger) can be measured by the method described in the examples below.

[0025] The spun yarn is preferably of a B value of 0.2 or higher and 1.6 or lower, calculated by the following formula (2). B = B1 / B2 ... (2) [In the formula, B1 is the number of fibers 5 mm or longer (fibers / 10 m), and B2 is the short fiber content (%).] As the short fiber content of spun yarn decreases, the amount of fluff tends to decrease. The B value in formula (2) is a value corrected by dividing the number of fluffs 5 mm or larger (fluffs / 10 m) by the short fiber content. A lower B value reduces the generation of fluff caused by factors other than the short fiber content. Therefore, the B value is more preferably 1.5 or less, and even more preferably 1.4 or less. On the other hand, a B value of 0.2 or more tends to result in a high-quality appearance and a smooth texture. Therefore, it is more preferably 0.3 or more, and even more preferably 0.4 or more. The B value can be measured by the method described in the examples below.

[0026] The spun yarn of this embodiment can be used in various forms such as woven fabrics, knitted fabrics, and other garments for clothing and other items. Examples include inner shirts such as underwear and undershirts; outer shirts such as T-shirts, polo shirts, dress shirts, and blouses; outerwear such as jackets and coats; pants such as denim pants, chino pants, and cargo pants; school uniforms; everyday clothing such as towels and tablecloths; and bedding clothing such as sheets, duvet covers, and pillowcases.

[0027] Next, a method for manufacturing spun yarn according to the embodiment will be described. The method for manufacturing spun yarn according to the embodiment includes the steps of cutting yarn containing cotton, textile products containing cotton, or both, at intervals of 30 mm or more and 45 mm or less, and defibrating them using a high-speed fluid to obtain a group of fibers having an effective fiber length of 24 mm or more and 29 mm or less, as measured by Method A of JIS-L1019 7.2.1. By cutting yarn containing cotton, textile products containing cotton, etc., at the predetermined intervals and defibrating them with a high-speed fluid, a group of fibers having an effective fiber length of 24 mm or more and 29 mm or less can be obtained. When a fine spun yarn with an English cotton count of 5 to 50 is formed using such a group of fibers, the effective fiber length can be increased, the short fiber content can be reduced, and the number of yarn-like slabs caused by the sticking out of old yarn can be reduced, resulting in the spun yarn of the embodiment described above. Furthermore, using the above group of fibers makes it less likely for the yarn to break during spinning.

[0028] In the manufacturing method of spun yarn, it is preferable that the yarn containing cotton, the textile product containing cotton, or both contain twisted cotton. For example, twisted cotton has longer fibers than untwisted cotton waste, making it easier to recycle.

[0029] Examples of cotton-containing yarns used in the manufacturing method of spun yarn include cotton-containing spun yarns, with cotton-containing spun yarns being preferred. When the recycled raw material is spun yarn (hereinafter also referred to as old yarn), the English cotton count is preferably 5 count or higher and 120 count or lower. A count of 5 count or higher makes it easier to defibrate. Therefore, it is more preferably 10 count or higher, and even more preferably 15 count or higher. On the other hand, a count of 120 count or lower makes it easier to defibrate. Therefore, it is more preferably 80 count or lower, and even more preferably 60 count or lower.

[0030] In the method for manufacturing spun yarn, in addition to the cotton-containing yarn and cotton-containing textile products mentioned above, untwisted fiber materials may also be used. Examples of untwisted fiber materials include those that have been recycled from wraps, slivers, or reeled bundles. Reasons for recycling include those identified as defective fiber bundles due to uneven thickness, poor winding, etc. Untwisted fiber materials may be used in processes such as cutting, or they may be mixed in subsequent processes.

[0031] Examples of textile products containing cotton used in the manufacturing method of spun yarn include woven and knitted fabrics containing cotton spun yarn. Examples of textile products include inner shirts such as underwear and undershirts; outer shirts such as T-shirts, polo shirts, dress shirts, and blouses; outerwear such as jackets and coats; pants such as denim pants, chino pants, and cargo pants; uniforms such as school uniforms; everyday clothing such as towels and tablecloths; and bedding clothing such as sheets, duvet covers, and pillowcases. These may be used individually or in combination of two or more types.

[0032] The cotton-containing yarn used in the method for manufacturing spun yarn is preferably pre-consumer recycled material, post-consumer recycled material, or a combination thereof, and more preferably pre-consumer recycled material. Examples of pre-consumer recycled material include off-spec spun yarn, defective yarn, and leftover yarn produced during the manufacturing process before reaching consumers. Examples of post-consumer recycled material include spun yarn obtained by unraveling textile products collected after use by consumers.

[0033] The textile products containing cotton used in the method for manufacturing spun yarn are preferably pre-consumer recycled materials, post-consumer recycled materials, or a combination thereof, and are more preferably pre-consumer recycled materials. Examples of pre-consumer recycled materials include scraps, cutting waste, and off-spec products of textile products generated during the manufacturing process before they reach consumers. Examples of post-consumer recycled materials include textile products collected after use by consumers.

[0034] The cutting interval is 30 mm or more and 45 mm or less. A cutting interval of 30 mm or more reduces the short fiber content and increases the effective fiber length. Furthermore, it makes spinning, such as ring spinning, easier. For this reason, the cutting interval is preferably 32 mm or more. On the other hand, a cutting interval of 45 mm or less makes it easier to defibrate with a high-speed fluid and shortens the defibration time. For this reason, the cutting interval is preferably 38 mm or less. The cutting process preferably includes a step of cutting in a first direction and a step of cutting in a second direction. The angle between the first direction and the second direction is preferably 80° or more and 100° or less, and most preferably 90°. This makes defibration even easier. Cutting in the first direction may be performed multiple times before cutting in the second direction, cutting in the first direction and cutting in the second direction may be performed alternately, cutting in the first direction and cutting in the second direction may be performed simultaneously, or cutting in the first direction may be performed only.

[0035] The manufacturing method for spun yarn may include a pretreatment step such as washing, bleaching, or fluorescent bleaching before cutting. On the other hand, dyed yarn may be used as is without bleaching, or it may be used mixed with undyed yarn.

[0036] By using a high-speed fluid for defibration, the fibers are less likely to be torn than when defibration is performed using a cutting machine or the like, thus reducing the load on the fibers. This allows for a reduction in the short fiber content and an improvement in the effective fiber length. For example, the cut material may be agitated, kneaded, and transported using a high-speed fluid. Alternatively, the cut material may be impacted by colliding it with a collision plate with strong force using a high-speed fluid, or it may be brought into contact with defibration teeth, and the shear force of the fluid may be used to promote defibration of the gripped fibers. The flow velocity of the high-speed fluid is preferably 10 m / s or more, more preferably 20 m / s or more, and even more preferably 30 m / s or more. This makes defibration easier. On the other hand, the flow velocity of the high-speed fluid is preferably 300 m / s or less, more preferably 200 m / s or less, even more preferably 100 m / s or less, and even more preferably 50 m / s or less. This further reduces the load on the fibers.

[0037] When defibrating with a high-speed fluid, it is preferable to use air as the high-speed fluid, but liquids such as water, or gases such as nitrogen gas or carbon dioxide gas may also be used. Compressed air may also be used. Specifically, when defibrating with a high-speed fluid, it is preferable to use a fluid-type defibration machine for short fibers. As a fluid-type defibration machine for short fibers, for example, the JET OPENER JO-3 manufactured by Tatsumi Air Engineering Co., Ltd. is preferred. With this defibration machine, a high-pressure fan creates a high-speed airflow to untie the fibers, and defibration teeth provided on the inner surface of the casing capture the fibers, promoting defibration with a high-speed jet airflow. Using a high-speed jet airflow allows for defibration with minimal fiber damage. It is preferable to connect the inlet and outlet of this JET OPENER and circulate the fiber raw material to perform defibration for a long period of time. Multiple units may also be connected and used. By defibrating in this way, it becomes easier to obtain fiber groups with long effective fiber lengths.

[0038] In the method for manufacturing spun yarn, it is preferable to apply oil to the cut material after cutting, before defibration with a high-speed fluid. This reduces friction between fibers and makes it easier to untangle them. The oil preferably contains organopolysiloxane, mineral oil, polyethylene smoothing agent, liquid paraffin, alkylbenzene oil, castor oil, palm oil, or a combination thereof, and more preferably contains organopolysiloxane. The oil is preferably applied as a defibration composition in the form of, for example, an aqueous dispersion or emulsion, and sprayed onto the cut material using a spray nozzle. The oil content is preferably 1 to 30% by mass, and more preferably 5 to 15% by mass, per 100 parts by mass of the defibration composition. The defibration composition is preferably applied in an amount of 1 to 10 parts by mass per 100 parts by mass of the cut material.

[0039] The method for manufacturing spun yarn may include a step of further defibration after defibration with a high-speed fluid. Examples of defibration devices in this step include a carding machine and a garnet machine. A carding machine is more preferred. A general carding machine used for spinning cotton may be used. When using a garnet machine, it is preferable to have multiple rotating drums. It is preferable that at least one of the multiple rotating drums has a spiky part. By rotating such a rotating drum, the spiky part can scratch and loosen the fiber material. In this case, it is preferable that the direction of rotation and / or rotation speed of the rotating drums facing each other with the fiber material in between are different. This makes it easier to loosen. The number of rotating drums is preferably 10 to 100, more preferably 20 to 80, and even more preferably 30 to 60. The spiky part can be formed, for example, by attaching a spiky wire to the rotating drum.

[0040] In the method for manufacturing spun yarn, the defibration rate can preferably be 95% or higher. More preferably 98% or higher, even more preferably 99.0% or higher, even more preferably 99.5% or higher, and particularly preferably 99.9% or higher. This improves the yield during spinning, such as ring spinning, and reduces the risk of yarn breakage caused by thread-like fiber waste from old yarn that could not be defibrated. On the other hand, the defibration rate may be 99.999% or lower, or 99.99% or lower. The defibration rate can be measured by taking 200g from any location in the fiber group obtained by defibration, visually removing the twisted thread-like fiber waste contained therein, measuring the mass (g) of the twisted thread-like fiber waste, and substituting it into the following formula. R(%) = (200 - W) × 100 / 200 [In the formula, R is the defibrillation rate (%), and W is the mass of filamentous fiber waste (g).]

[0041] The method for producing spun yarn preferably includes a step of spinning using the obtained fiber group. Examples of spinning methods include ring spinning, open-end spinning, and bundled spinning, with ring spinning being preferred. In the spinning step, virgin cotton and / or waste cotton may be mixed with the fiber group obtained by defibration, i.e., regenerated cotton, before spinning. The content of these materials should be referred to in the description of the spun yarn in the embodiment.

[0042] The method for manufacturing spun yarn preferably includes a pre-treatment step before spinning. Examples of such steps include general processes such as blending, carding, drawing, and roving. For example, the obtained fiber group may be uniformly mixed in a blending machine, and then a carded sliver with a preferred density of 200-400 gelens / 6yd may be formed in a carding machine. Next, if necessary, a combing treatment may be performed, and the sliver may be passed through a drawing machine preferably 1-3 times to obtain a drawn sliver with a preferred density of 200-400 gelens / 6yd. Next, it may be processed into roving yarn with a preferred density of 90-300 gelens / 15yd in a roving machine, and then spun in a ring spinning machine, preferably under conditions of draft: 16-35 times, spindle rotation speed: 3,000-8,000 rpm, and twist coefficient (K value): 2.8-5.0. If necessary, treatments such as negative pressure air suction or magnetic pressure may be performed, or compact spinning may be performed. [Examples]

[0043] 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, and can be implemented with modifications within the scope that is consistent with the spirit of the preceding and following descriptions, and all such modifications are included within the technical scope of the present invention. The measurements and evaluations of each example, comparative example, and reference example were performed by the following methods.

[0044] <Effective fiber length and short fiber content> The effective fiber length and short fiber content of spun yarn were measured according to Method A (double sorter method) of fiber length as specified in JIS-L1019-7.2.1. Specifically, the test environment was 20°C and 65% RH. The spun yarn was unraveled into fibers, and a staple diagram was prepared to determine the short fiber content and effective fiber length. The effective fiber length was similarly determined for the fibers after defibration.

[0045] English cotton count The apparent cotton count (English count) of the spun yarn was measured according to the method of JIS-L1095(2010)9.4.2.

[0046] <Twist coefficient> The number of twists in the spun yarn was measured according to Method A of JIS-L1095(2010)9.15.1, and the twist coefficient (K) was calculated by applying it to the following formula. Twist coefficient (K) = Number of twists per inch (T) / √ Yarn count ('s)

[0047] <Number of filamentous slabs> The number of filamentous slabs in spun yarn was measured using the CLASSIFAULT TRI CHORD FLEX Ver.2.3.6 yarn defect classification device from Keisokuki Kogyo Co., Ltd. Specifically, an optical sensor was used, and the measurement speed was set to 600 m / min to detect major defects and collect the defective parts. Major defects were defined as three types of defects: those exceeding +400% of the yarn's cross-sectional thickness with a length of 0.1 cm or more, those exceeding +250% with a length of 2 cm or more, and those exceeding +150% with a length of 4 cm or more. First, the number of slabs per 10,000 m of yarn was measured. Next, the slabs collected by the testing machine were visually inspected to determine if they contained filamentous fiber debris, and only filamentous slabs were selected. Finally, the number of filamentous slabs per 10,000 m of yarn was calculated from the measured length (slabs / 10,000 m). For slabs where it was difficult to determine whether they were filamentous slabs by external observation, the slab was unraveled to check for the presence of twisted filamentous fiber debris, and then the determination was made.

[0048] <Worcester yarn unevenness> The Worcester unevenness (U%) of spun yarn was measured according to Method A of JIS L1095(2010)9.20.1. A yarn unevenness tester, KET-80V / B manufactured by Keisokuki Kogyo Co., Ltd., was used, with a measurement speed of 200 m / min and a measurement time of 2 minutes.

[0049] <Number of lints longer than 5mm> The number of 5mm or longer fibers (fibers / 10m) was measured according to Method B of JIS-L1095(2010)9.22.1. Specifically, an F-Index Tester manufactured by Shikibo Co., Ltd. was used, with a yarn length of 10m, to measure the number of 5mm or longer fibers.

[0050] <Spinning property> Splicability was evaluated by the number of yarn breaks when the fiber group was put through a spinning machine. Specifically, the number of yarn breaks was measured when 400 spindles were operated for one hour, and evaluated on the following four-point scale. ◎: 2 or less ○: 3-5 pieces △: 6 or more ×: Unable to spin

[0051] <Recycled Cotton 1> As a pre-consumer raw material, waste yarn that was deemed to be outside the standard count during the inspection stage of the process of manufacturing combed cotton yarn with an English count of 40 at a spinning mill was used as the starting material. Cut fibers were produced by passing 100 strands of waste yarn through a cutting machine with a cutting interval of 35 mm. Then, a 10% by mass emulsion aqueous solution of organosilicone oil was spray-coated at a rate of 5 parts by mass per 100 parts by mass of cut fibers. Next, the cut fibers were processed for 15 minutes at a flow rate of 40 m / s using a structure in which two JET OPENER JO-3 manufactured by Tatsumi Air Engineering Co., Ltd. were connected in a row to circulate the cut fibers, and then passed through a carding machine manufactured by Ishikawa Seisakusho Co., Ltd. to obtain a group of recycled cotton fibers (recycled cotton 1). Almost no unfibrillated fiber bundles were observed in this group of fibers, the fibrillation rate was approximately 100%, and the effective fiber length was 27 mm.

[0052] <Recycled Cotton 2> As a post-consumer raw material, cotton knit underwear collected from retail stores was used as the starting material. This cotton knit underwear was manufactured using combed cotton yarn with an English cotton count of 40. The starting material was cut into fibers by passing it through a cutting machine with a cutting interval of 30 mm. Then, a 10% by mass emulsion aqueous solution of organosilicone oil was spray-coated at a rate of 5 parts by mass per 100 parts by mass of cut fibers. Next, two JET OPENER JO-3 machines manufactured by Tatsumi Air Engineering Co., Ltd. were connected in a row to circulate the cut fibers, and the material was processed at a flow rate of 40 m / s for 25 minutes. After that, it was passed through a carding machine manufactured by Ishikawa Seisakusho Co., Ltd. to obtain a group of recycled cotton fibers (recycled cotton 2). The defibration rate of this fiber group was 99.8%, and the effective fiber length was 25 mm.

[0053] <Recycled Cotton 3> As a pre-consumer raw material, waste yarn that was deemed to be outside the standard count during the inspection stage of the process of manufacturing combed cotton yarn with an English count of 40 at a spinning mill was used as the starting material. 100 strands of waste yarn were passed through a cutting machine with a cutting interval of 55 mm. After being recycled using six rotating cutting machines manufactured by Asahi Cotton Machinery Co., Ltd., which were connected in series, the recycled yarn was passed through a 4-peak garnet machine to obtain a fiber group (recycled cotton 3), which is recycled cotton from the recycled fibers. This fiber group showed many fiber bundles that were not sufficiently defibrated, with a defibration rate of 97% and an effective fiber length of 22 mm.

[0054] <Example 1> Recycled cotton 1 was used at a content of 100% by mass and blended in an OHARA blending machine. Then, a carded sliver of 300 gelens / 6yd was spun using a carding machine manufactured by Ishikawa Seisakusho Co., Ltd. This carded sliver was passed twice through a drawing machine manufactured by Hara Loom Works to obtain a drawn sliver of 400 gelens / 6yd. Furthermore, this sliver was passed through a roving machine manufactured by Toyota Industries Corporation to produce roving yarn of 210 gelens / 15yd. Finally, using a ring spinning machine manufactured by Toyota Industries Corporation, the yarn was spun at a draft of 18 times and a traveler rotation speed (spindle rotation speed) of 6000 rpm to obtain English cotton count 10 yarn. The twist coefficient (K) at that time was 3.0 (twist count 9.5T / inch).

[0055] <Example 2> Using recycled cotton 1 at a content of 100% by mass, the roving weight was set to 130 gelens / 15yd, and a draft of 21.8 times was applied in a spinning machine to produce a 20 / 1 yarn. The process was carried out in the same manner as in Example 1, except that the twist coefficient (K) was adjusted to 3.0 (twist count 9.5 T / inch).

[0056] <Example 3> Recycled cotton 1 was used at a content of 100% by mass and blended using an OHARA blending machine, and then carded sliver was spun using a carding machine manufactured by Ishikawa Seisakusho Co., Ltd. Next, the carded sliver was put through a combing machine to obtain combed sliver with a yield of 300 gelenes / 6 yd. The combed sliver was doubled and drafted twice in a drawing machine to produce drawn sliver with a yield of 300 gelenes / 6 yd. Next, it was put through a roving machine to obtain roving yarn with a yield of 110 gelenes / 15 yd. Using the resulting roving yarn, a draft of 35 times was applied in a spinning machine, and it was spun with a twist coefficient (K) of 3.6 to obtain spun yarn of English cotton count 40.

[0057] <Example 4> Recycled cotton 2 was used at a content of 100% by mass and blended in an OHARA blending machine. Then, a carded sliver of 300 gelens / 6yd was spun using a carding machine manufactured by Ishikawa Seisakusho Co., Ltd. This carded sliver was passed twice through a drawing machine manufactured by Hara Loom Works to obtain a drawn sliver of 400 gelens / 6yd. Furthermore, this sliver was passed through a roving machine manufactured by Toyota Industries Corporation to produce roving yarn of 210 gelens / 15yd. Finally, using a ring spinning machine manufactured by Toyota Industries Corporation, the draft was increased to 18 times to obtain a spun yarn of English cotton count 10. The twist coefficient (K) at that time was 3.0 (twist count 9.5T / inch).

[0058] <Comparative Example 1> Recycled cotton 3 was used at a content of 100% by mass and blended in an OHARA blending machine. Then, a carded sliver of 300 gelens / 6yd was spun using a carding machine manufactured by Ishikawa Seisakusho Co., Ltd. The sliver obtained from the carding machine was passed twice through a drawing machine manufactured by Hara Loom Works to obtain a drawn sliver of 400 gelens / 6yd. Furthermore, this sliver was passed through a roving machine manufactured by Toyota Industries Corporation to produce roving yarn of 210 gelens / 15yd. Finally, using a ring spinning machine manufactured by Toyota Industries Corporation, the yarn was spun at a draft of 18 times and a traveler rotation speed (spindle rotation speed) of 6000 rpm to obtain English cotton count 10 yarn. The twist coefficient (K) at that time was 3.0 (twist count 9.5T / inch).

[0059] <Comparative Example 2> Using the same recycled cotton 3 as in Comparative Example 1, roving yarn with a density of 130 gelens / 15 yd was prepared. Attempts were made to spin this yarn into 20 / 1 yarn using a ring spinning machine manufactured by Toyota Industries Corporation with a draft of 21.8 times, but it could not be spun due to poor spunability.

[0060] <Reference example 1> Using non-recycled virgin cotton raw material, Upland cotton (long-staple cotton, effective fiber length 28 mm) was blended at a content of 100% by mass in an OHARA blending machine, and then a carded sliver of 300 gelens / 6 yd was spun using a carding machine manufactured by Ishikawa Seisakusho Co., Ltd. The sliver obtained from the carding machine was passed twice through a drawing machine manufactured by Hara Loom Works to obtain a drawn sliver of 300 gelens / 6 yd. Furthermore, this sliver was passed through a roving machine manufactured by Toyota Industries Corporation to produce roving yarn of 130 gelens / 15 yd. Then, using a ring spinning machine manufactured by Toyota Industries Corporation, the yarn was spun at a draft of 21.8 times and a traveler rotation speed (spindle rotation speed) of 6000 rpm to obtain spun yarn with an English cotton count of 20 / 1. The twist coefficient (K) at that time was 3.0 (twist count 9.5 T / inch).

[0061] The characteristics and evaluation results of these spun yarns are shown in Table 1.

[0062] [Table 1]

[0063] As shown in Table 1, in Examples 1 to 4, by cutting the fibers at intervals within a predetermined range and defibrating them with a high-speed fluid, a group of long fibers with an effective fiber length within a predetermined range was obtained. Furthermore, when fine spun yarn with an English cotton count of approximately 5 to 50 was formed using such a group of fibers as raw material, a spun yarn was obtained that had a long effective fiber length, a low short fiber content, and a small number of filamentous slabs caused by the protrusion of old yarn, etc., as a recycled yarn. In addition, since it was possible to form a fine spun yarn, it is thought that there was almost no fiber damage associated with defibration.

[0064] On the other hand, in Comparative Example 1, the cutting interval was long and the fibers were re-cut using a rotary cutting machine, resulting in a group of fibers that were not sufficiently defibrated. Furthermore, it is thought that the number of filamentous slabs in the resulting spun yarn increased as a result of using such a group of fibers as raw material to form a fine spun yarn.

[0065] In Comparative Example 2, the fibers were re-cut using a rotary cutting machine, which put stress on them and made them prone to breaking. As a result, it is thought that fine spun yarn could not be produced.

Claims

1. It is a spun yarn, Including cotton, The effective fiber length of the cotton, as measured by Method A of JIS-L1019 7.2.1, is 21 mm or more and 28 mm or less, and the short fiber content is 25% or more and 45% or less. English cotton count is 5 count or higher and 50 count or lower, and A spun yarn having a number of filamentous slabs of 1 or more (slabs / 10,000m) and 35 or less (slabs / 10,000m).

2. The spun yarn according to claim 1, which is a ring-spun yarn.

3. The spun yarn according to claim 1, wherein the Worcester yarn unevenness (U%) is 5.0% or more and 30% or less.

4. The spun yarn according to claim 3, wherein the A value calculated by the following formula (1) is 0.20 or more and 3.0 or less. A=A1 / A2...(1) [In the formula, A1 is the Worcester yarn unevenness (U%), and A2 is the English cotton count (count).]

5. The spun yarn according to claim 1, wherein the number of fluffs of 5 mm or more is 10 (fluffs / 10 m) or more and 50 (fluffs / 10 m) or less.

6. The spun yarn according to claim 5, wherein the B value calculated by the following formula (2) is 0.2 or more and 1.6 or less. B=B1 / B2...(2) [In the formula, B1 is the number of fibers 5 mm or longer (fibers / 10 m), and B2 is the short fiber content (%).]

7. A process of cutting yarn containing cotton, textile products containing cotton, or both thereof, at intervals of 30 mm or more and 45 mm or less, and A method for producing spun yarn, comprising the step of using a high-speed fluid to defibrate and obtain a group of fibers having an effective fiber length of 24 mm or more and 29 mm or less as measured by Method A of JIS-L1019 7.2.1.

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