Preparation method of Ganma yarn

Abstract

The invention belongs to the technical field of textile, and particularly relates to a preparation method of soft yarn. Long stapled cotton, fine staple cotton and water-soluble filaments are used as raw materials, blowing, cotton carding, pre-drawing, lap forming, combing, secondary drawing, vortex spinning, automatic spooling, slashing and two-for-one twisting doubling are carried out, and the plied yarn wrapped soft yarn with the single yarn and the plied yarn being opposite in twist degree and the water-soluble filaments serving as cores is prepared. The water absorption, the softness, the yarn strength and the product durability are difficult to balance.

Description

Technical Field

[0001] The invention belongs to the field of textile technology, and more particularly relates to a method for preparing Roulan yarn. Background Art

[0002] In daily life, towels are indispensable daily necessities, and their performance directly affects the user experience. However, existing towel products made from ordinary cotton yarn generally have many problems. First, insufficient water absorbency is a major drawback of traditional pure cotton towels. Due to the dense yarn structure of traditional pure cotton towels and the narrow gaps between fibers, it is difficult for water to quickly penetrate into the fibers, resulting in a significant limitation in both the speed and amount of water absorbed. For example, when wiping the body or objects, repeated wiping is often required to achieve the desired drying effect, which is very inconvenient. Secondly, hardening after use is also a common problem. After repeated washing, the twist of cotton yarn gradually stabilizes. As the friction between fibers increases, they adhere to each other, causing the towel to feel hard. A towel that was originally soft and comfortable becomes rough and stiff after a period of use, which not only reduces the user comfort but also may cause certain irritation to the skin.

[0003] To address these issues, some towels in the prior art use low-twist yarn or untwisted yarn technology, but these technologies also have significant shortcomings. During the weaving process, low-twist yarn is prone to end breakage due to insufficient yarn strength, which can seriously affect production efficiency and increase production costs. Although untwisted yarn can improve the softness of towels to a certain extent, the cotton fibers are easily shed during use, resulting in reduced durability of the towels and shortened product lifespan. In addition, in order to achieve ideal performance, some technologies require the addition of chemical softeners. This may not only pollute the environment and be inconsistent with the current green and environmentally friendly development concept, but these chemicals may also remain on the towels, irritating the user's skin and causing adverse reactions such as allergies. In summary, existing towel products and their improved technologies all have certain problems. The development of a new type of towel product that has good water absorption and softness, high strength, good durability, and an environmentally friendly process that does not shed or remove lint is of great practical significance and is also a common requirement of high-end towel consumers. Summary of the Invention

[0004] In the field of towel manufacturing, the balance between water absorption, softness, yarn strength and product durability has always been a difficult problem to overcome. The present invention provides a method for preparing Roulan yarn, which provides a new solution to these problems.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention is to provide a method for preparing Roulan yarn, comprising the following steps:

[0007] The Roulan yarn is prepared from long-staple cotton, fine-staple cotton and water-soluble filament as raw materials through the processes of blowing, carding, pre-drawing, sliver winding, combing, second drawing, vortex spinning, automatic winding, sizing and doubling.

[0008] Furthermore, the mass ratio of the long-staple cotton, the fine-staple cotton and the water-soluble filament is 6:3:1.

[0009] Furthermore, the fiber length of the long-staple cotton is not less than 38 mm.

[0010] Furthermore, the fiber length of the fine-staple cotton is not less than 28 mm.

[0011] Furthermore, the long-staple cotton and the fine-staple cotton have a breaking strength of ≥29 cN / tex, an impurity content of ≤2.5%, and a moisture regain of 8-9%.

[0012] Furthermore, the water-soluble filaments are polyvinyl alcohol (PVA) water-soluble filaments with an alcoholysis degree of 85-97 mol% and a dissolution temperature of 80-90°C.

[0013] The fiber length of raw cotton (long-staple cotton and fine-staple cotton) affects the yarn strength and spinnability, the breaking strength affects the yarn's tensile strength, excessive impurities affect the subsequent impurity removal efficiency, and the moisture regain affects the fiber's softness and processing performance.

[0014] The Roulan yarn provided by the present invention has a reasonable cotton blend, with long-staple cotton and fine-staple cotton each accounting for a certain proportion, so that the yarn not only has good tensile strength, but also has elastic elongation, the yarn is uniform and smooth, and the single yarn is both soft and has a certain strength, laying a good foundation for the subsequent plying processing.

[0015] Furthermore, the cotton cleaning parameters are as follows: the cotton plucker beater speed is 500 r / min; the impurity removal efficiency is 60%-70%; and the cotton roll quantitative deviation is ≤1.2%.

[0016] The blowroom process includes opening, cleaning, blending, and lap formation. During opening, the beater speed of the plucker is 500 r / min. A higher speed enhances the opening effect, but the speed is slightly lower than normal to prevent breakage of the water-soluble yarn. The blowroom process removes 60%-70% of large impurities, reducing the trash content to below 1.0%. The lap basis weight deviation is ≤1.2% to avoid affecting subsequent carding uniformity. This blowroom process removes some impurities, defects, and short fibers from the fibers, leaving them clean.

[0017] Furthermore, the carding parameters are as follows: cylinder speed is 310 rpm; doffer speed is 20 rpm; the distance between the licker-in roller and the cylinder is 0.25 mm; the card sliver basis weight is 18-25 g / 5 m; the neps of the pure cotton card sliver are ≤80 / g and the short lint rate is ≤12%.

[0018] Increasing the cylinder speed during carding can improve the carding effect, but will increase fiber damage; the doffer speed determines the sliver output speed, affecting the output and sliver uniformity; the smaller the gap between the licker-in roller and the cylinder, the finer the carding, but the fibers are more easily entangled; after the carding process, the transverse connection between the fibers is basically eliminated, and the longitudinal connection between the end and the end is gradually established.

[0019] Furthermore, the parameters of the pre-drawing are as follows: the number of slivers is 8; the total drafting multiple is 6 times, the back zone drafting is 1.2 times; the roller spacing is 28-30mm; the quantitative deviation of the pre-drawn sliver is ≤1.0%, and the CV value of the sliver is ≤4.5%.

[0020] In the pre-drawing (first drawing), the number of draws is 8 to improve the uniformity, and the parallelism of the fibers is adjusted by drawing.

[0021] Furthermore, the parameters of the strip roll are as follows: the number of strips to be combined is 18 pre-drawn strips; the strips are wound into a roll, 20 strips x 3 layers, and the strip roll density is 0.4g / cm 3 ; Roller speed (roller output speed) is 120m / min; quantitative deviation ≤0.6%.

[0022] Too dense sliver density in the sliver roll can easily cause combing difficulties, roller speed affects production efficiency, and the quantitative deviation is ≤0.6%, ensuring uniform feeding in subsequent combing.

[0023] Furthermore, the combing parameters are: cylinder speed 350r / min; cotton drop rate 19%; cylinder card clothing density 320 needles / m 2 ; The weight of the combed sliver is 18g / 5m.

[0024] During combing, one end of the fiber layer is held and the other end is combed. Combing removes tiny impurities and short fibers, straightens the fibers, reduces length unevenness, and allows different fibers to be mixed.

[0025] Furthermore, the parameters of the second drawing are as follows: the number of slivers is 6; the total drafting multiple is 6 times, the back zone drafting is 1.05 times; the roller spacing is 26-28 mm; the quantitative deviation of the sliver after the second drawing is ≤0.5%, and the CV value of the sliver is ≤3.5%.

[0026] Furthermore, the parameters of the vortex spinning are: spindle speed of 4500 rpm (vortex spinning machine main shaft speed); nozzle air pressure of 0.58 MPa; twist direction of S twist; drawing to 32 counts; twist of 58-60 twists / m.

[0027] The water-soluble silk is wrapped around the core of the yarn under the action of the vortex airflow. The outer layer is a mixture of long-staple cotton and fine-staple cotton fibers wrapped around the water-soluble silk in the S-twist direction. The twist parameter is an important parameter of this process. Otherwise, the subsequent untwisting will affect the softness and strength of the fabric. Among them, the breaking strength of the single yarn after vortex spinning treatment is ≥16cN / tex.

[0028] Furthermore, the parameters of the automatic winding are: winding speed of 1500m / min; defect removal range of thick places +50% to +200%, thin places -30% to -70%, and cotton neps +20% to +50%; the winding density of the yarn is 0.39-0.45g / cm 3 .

[0029] Furthermore, the parameters of the sizing are: slurry concentration of 5.5wt% (starch + PVA mixed slurry, the mass ratio of starch and PVA is 7:3); sizing rate of 5%; sizing tank temperature of 40-45°C; drying temperature of 60-70°C; yarn elongation ≤1.3%.

[0030] Sizing according to the above technical parameters can just fix the twist of the core-spun single yarn, preparing for the next process of reverse twisting, and the warp tension uniformity is ≤4%.

[0031] Furthermore, the parameters of the double twisting and doubling are as follows: the number of doubling yarns is 2 spun yarns (single yarns after sizing); the double twisting degree is 58 twists / m; the tension uniformity of the winding tension is ≤4%; and the twist direction of the strands is Z twist.

[0032] The key technology in the doubling and plying process is that when two single yarns are twisted, the twist direction of the ply yarn is opposite to that of the single yarn. The single yarn is S twisted and the ply yarn is Z twisted. Since the single yarn has been sizing, it will not be untwisted due to the opposite twist direction during the plying process. Reasonable twist is the key to this process. If the twist is too small, there will be many remaining twists during the subsequent back twisting, and the hand feel is not good. If the twist is too large, the fibers will be untwisted during the back twisting and become untwisted. The fabric strength is low, which affects the service life.

[0033] The present invention rationally mixes long-staple cotton, fine-staple cotton and water-soluble silk, cleverly combines the application of high-temperature water-soluble silk with double-twist technology, and uses special spinning and single-yarn sizing processes to accurately embed the water-soluble silk into the yarn core. In the subsequent processing link, after the water-soluble silk is dissolved under high-temperature conditions, the yarn is in a hollow state, and the fibers quickly absorb water and expand, making the fabric soft and fluffy. The fabric becomes softer and softer with increasing number of uses.

[0034] The core of the present preparation method lies in the combination of high-temperature water-soluble silk and dual-twist technology. Specifically, the present invention uses polyvinyl alcohol (PVA) water-soluble silk (hereinafter referred to as water-soluble silk) and utilizes a special spinning process to precisely embed it into the yarn core. In subsequent processing, high temperature conditions (during the dyeing process during the application process) dissolve the water-soluble silk, leaving the yarn hollow. This unique hollow structure greatly increases the inter-fiber spacing, providing a wider space for water, significantly improving the towel's water absorption, enabling it to quickly absorb large amounts of water and meet the high efficiency requirements of daily use. Furthermore, the process utilizes a special spinning technique that gradually reduces the yarn twist with increasing use. This characteristic creates a terry loop that produces a completely different effect from that of conventional yarn, becoming increasingly fluffier and softer with repeated use. This not only effectively solves the problem of traditional towels becoming stiff after use, but also significantly improves comfort during use, giving users a cloud-like soft touch experience. It is worth noting that this process improves softness and water absorption without sacrificing yarn strength or product durability. The formation of the hollow structure and the clever variation in twist do not affect the overall stability of the yarn, ensuring that the towel maintains its good shape and performance during long-term use and multiple washings, thus extending the product's service life. The Roulan yarn production process provided by this invention has brought new development directions to the towel manufacturing industry and is expected to promote towel products towards higher quality and better performance.

[0035] The second technical solution of the present invention is to provide a Roulan yarn, which is prepared by the above-mentioned preparation method.

[0036] When the Roulan yarn prepared by the present invention is packaged, the yarn package weight is controlled at about 50 kg, the weight deviation is controlled at ≤±0.5%, and the packaging pressure is controlled at 0.2-0.3 MPa, ensuring that the yarn package is compact and not easily deformed.

[0037] The Roulan yarn is a coated ply yarn with opposite twists between single yarn and ply yarn and a water-soluble silk core.

[0038] The third technical solution of the present invention is to provide an application of the above-mentioned Roulan yarn in the preparation of household textiles.

[0039] The present invention discloses the following technical effects:

[0040] The Roulan yarn of the present invention rationally mixes long-staple cotton, fine-staple cotton and water-soluble fiber, optimizes the technical parameters of each process, and forms a new type of Roulan yarn with S twist on single yarn, Z twist on ply yarn and water-soluble silk wrapped in the core of the single yarn.

[0041] The twist direction of the Roulan yarn provided by the present invention is opposite to that of the ply yarn, that is, the single yarn is S-twisted and the ply yarn is Z-twisted. This cannot be achieved according to the normal plying process because the two single yarns will untwist and break during the reverse plying and twisting process. For this reason, the present invention performs sizing treatment on the single yarn before plying. Because the core of the single yarn contains soluble water-soluble silk, the sizing temperature should be controlled within a reasonable range and the sizing rate should not be too high, otherwise the single yarn will be too hard and not conducive to plying.

[0042] The core of the Roulan yarn provided by the present invention is a soluble water-soluble silk. During the post-processing process (dyeing process), the water-soluble silk will completely dissolve when exposed to high temperature, making the yarn form a hollow core. Water will quickly fill the hollow fibers, so the Roulan yarn has excellent water absorption properties. At the same time, because the core is hollow, when it comes into contact with water, the water will quickly penetrate the fiber core, causing the fibers to expand, the yarn volume to increase, and the loops to become fluffy, thereby solving the problem of ordinary cotton fiber yarns that the fibers adhere to each other and shrink when exposed to water, causing the yarn volume to decrease.

[0043] The twist of the single yarn and the ply yarn of the Roulan yarn provided by the present invention are opposite. After post-processing and dyeing, the single yarn is desized and gradually detwisted under the action of the reverse twist of the ply yarn. As the number of uses increases, the twist of the single yarn will become smaller and smaller, and the fabric will become softer and softer, while ordinary towel products will become harder and harder as the number of uses increases.

[0044] The raw materials of the Roulan yarn provided by the present invention are high-quality long-staple cotton and fine-staple cotton. In addition, the combing process in the spinning process completely removes short fibers. The single yarn is configured with a reasonable twist, and no short fibers will fall out during subsequent use, solving the problem of ordinary towel products shedding lint during use. DETAILED DESCRIPTION

[0045] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0046] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0047] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0048] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be illustrative only.

[0049] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0050] The raw materials and reagents involved in the specific embodiment of the present invention are all commercially available products, among which the fiber length of long-staple cotton is not less than 38 mm, the fiber length of fine-staple cotton is between 28-33 mm, the breaking strength of long-staple cotton and fine-staple cotton is ≥29 cN / tex, the impurity content is ≤2.5%, and the regain is 8-9%; the polyvinyl alcohol (PVA) water-soluble silk has a degree of alcoholysis between 85-97 mol% and a dissolution temperature between 80-90°C.

[0051] Unless otherwise specified, the room temperature and normal temperature involved in the specific embodiments of the present invention refer to 20-30°C.

[0052] It should be pointed out that the matters not described in detail in the present invention are conventional operating means in this field and are not the focus of the present invention.

[0053] Example 1

[0054] The preparation steps of Roulan yarn are as follows:

[0055] S1. Raw material preparation: prepare long-staple cotton, fine-staple cotton and polyvinyl alcohol (PVA) water-soluble silk (hereinafter referred to as water-soluble silk) in a mass ratio of 6:3:1;

[0056] S2, the parameters of the cleaning process are set as follows:

[0057] a. Beater speed of plucking machine (unit: r / min): 500 r / min. The higher the speed, the stronger the opening effect. Slightly lower than the normal speed to prevent breakage during processing;

[0058] b. Impurity removal: The blowroom process needs to remove 60%-70% of large impurities in the raw cotton (long-staple cotton and fine-staple cotton), and reduce the impurity content to below 1.0%;

[0059] c. Control the unevenness of cotton lap weight: the deviation of cotton lap weight should be ≤1.2% to avoid affecting the uniformity of subsequent carding;

[0060] Through the blow room process, some impurities, defects and short fibers in the fiber are removed to make the fiber clean;

[0061] S3, carding process parameters are set as follows:

[0062] a. Cylinder speed (unit: r / min): 310 r / min. Although high speed can improve the carding effect, it will increase fiber damage;

[0063] b. Doffer speed (unit: r / min): 20 r / min, determines the sliver output speed, affects the output and sliver uniformity;

[0064] c. Gauge between licker-in and cylinder (unit: mm): 0.25mm. The smaller the gauge, the finer the combing, but the easier it is to entangle the fibers.

[0065] d. Sliver neps (neps / g): Pure cotton sliver neps ≤ 80 neps / g, short lint rate ≤ 12%;

[0066] Through the carding process, the horizontal connection between the fibers is basically eliminated, and the vertical connection between the end and the end is gradually established;

[0067] S4, pre-drawing (first drawing) process parameters are set as follows:

[0068] a. Number of merging (roots): 8 slivers are merged to improve uniformity;

[0069] b. Drafting ratio: total drafting ratio is 6 times, rear drafting ratio is 1.2 times (slight drafting to adjust fiber parallelism);

[0070] c. Roller gauge (unit: mm): between 28-30mm;

[0071] d. Drawing weight unevenness (%): Pre-drawn sliver quantitative deviation ≤ 1.0%, sliver dryness CV value ≤ 4.5%;

[0072] S5. The parameters of the strip coiling process are set as follows:

[0073] a. Number of strands: 18 strands pre-drawn and wound into strips, 20 strands x 3 layers;

[0074] b. Winding density (unit: g / cm3): strip density is about 0.4g / cm 3 (Too dense can easily make combing and combing difficult);

[0075] c. Roller speed (unit: m / min): The output speed of the sliver roll machine is about 120 m / min (speed mainly affects production efficiency);

[0076] d. Sliver weight unevenness (%): quantitative deviation ≤ 0.6% (to ensure uniform combing feeding);

[0077] S6. The combing process parameters are set as follows:

[0078] a. Cylinder speed (unit: r / min): comber speed is 350 r / min (high speed (higher than 350 r / min) increases production but increases energy consumption);

[0079] b. Noil rate (%): The combing process removes short fibers and impurities, and the noil rate is 19%;

[0080] c. Carding degree: Cylinder card cloth density 320 needles / m 2 , the more times you comb, the smoother the fiber;

[0081] d. Combed sliver weight (unit: g / 5m): Combed sliver weight is about 18g / 5m, which is slightly lighter than pre-drawn sliver and has purer fibers;

[0082] During the combing process, one end of the fiber layer is held and the other end is combed. Combing removes small impurities and short fibers, straightens the fibers, reduces length unevenness, and allows different fibers to blend.

[0083] S7, the second drawing process parameters are set as follows:

[0084] a. Number of slivers: 6 combed slivers are combined to further improve uniformity;

[0085] b. Drafting ratio: total drafting ratio is 6 times, rear zone drafting ratio is 1.05 times (fine-tuning fiber arrangement);

[0086] c. Roller gauge (unit: mm): set between 26-28 mm to adapt to the straighter fibers of the combed sliver;

[0087] d. Uneven weight of cooked strips (%): quantitative deviation of cooked strips after the second drawing is ≤0.5%, and CV value of strips is ≤3.5%;

[0088] S8, vortex spinning process parameters are set as follows:

[0089] a. Spindle speed: 4500r / min (vortex spinning machine spindle speed);

[0090] b. Nozzle air pressure: 0.58MPa;

[0091] c. Twist direction: S twist;

[0092] d. Drafting multiple: directly draw the drawn sliver to 32 count;

[0093] e. Twist: 58-60 twists / m;

[0094] f. Single yarn breaking strength: ≥16cN / tex;

[0095] Adjust the equipment according to the vortex spinning process parameters. The water-soluble silk is wrapped around the core of the yarn under the action of the vortex airflow. The outer layer is a mixture of long-staple cotton and fine-staple cotton fibers wrapped around the water-soluble silk in the S-twist direction. The twist parameter is an important parameter of this process. Otherwise, the subsequent untwisting will affect the softness and strength of the fabric.

[0096] S9, the automatic winding process parameters are set as follows:

[0097] a. Winding speed (unit: m / min): high-speed winder 1500 m / min;

[0098] b. Thick place detection: +50% - +200% (relative to the average diameter of the yarn), to remove thick place defects;

[0099] c. Detail inspection: -30% to -70%, eliminating the risk of broken ends;

[0100] d. Cotton nep detection: +20% - +50%, adjusted according to fabric requirements (e.g., knitting yarn cotton nep requirements are stricter);

[0101] e. Cone winding density (unit: g / cm 3 ): 0.42 (± 0.03) g / cm 3 , does not affect the smoothness of unwinding in the subsequent process, and prepares for the next process of sizing and twisting;

[0102] S10, sizing process parameters are set as follows:

[0103] a. Slurry concentration (%): 5.5% (starch + PVA mixed slurry, starch: PVA = 7:3);

[0104] b. Sizing rate (%): 5%;

[0105] c. Slurry tank temperature (℃): between 40-45℃;

[0106] d. Drying temperature (℃): between 60-70℃ (ensure the yarn moisture regain is ≤8%);

[0107] e. Tension control (uniformity, %): warp tension uniformity ≤ 4%;

[0108] f. Yarn elongation (%): ≤1.3% (control tensile deformation and maintain yarn strength);

[0109] The sizing process is carried out according to the above technical parameters, which just fixes the twist of the core-spun single yarn and prepares it for the next process of reverse twisting.

[0110] S11, the parameters of the two-for-one twisting and doubling process are set as follows:

[0111] a. Number of parallel yarns: 2 yarns paralleled;

[0112] b. Twist (unit: twist / m): twist 58 twist / m;

[0113] c. Winding tension (uniformity, %): Tension uniformity ≤ 4% to avoid loosening or breaking of strands;

[0114] d. Ply twist direction: Z twist, to improve structural stability;

[0115] The key to the two-for-one twisting and doubling technology is that when two single yarns are twisted, the twist direction of the ply yarn is opposite to that of the single yarn. The single yarn is S twisted and the ply yarn is Z twisted. Since the single yarn has been sizing, it will not be untwisted due to the opposite twist direction during the plying process. Reasonable twist is the key to this process. If the twist is too small, there will be many remaining twists during the subsequent back twisting, and the hand feel is not good. If the twist is too large, the fibers will be untwisted during the back twisting, and the fabric will be weak, which will affect the service life.

[0116] S12, the parameters of the packaging process are set as follows:

[0117] a. Package weight specification (kg): Yarn package weight 50kg, weight deviation ≤±0.5%;

[0118] b. Packaging: The packaging pressure is controlled at 0.2-0.3MPa to ensure that the yarn package is compact and not easily deformed.

[0119] The Roulan yarn prepared by the preparation method shown in the embodiment of the present invention is a coated ply yarn with opposite twists of single yarn and ply yarn and water-soluble silk as the core. Long-staple cotton, fine-staple cotton and water-soluble silk are reasonably proportioned, and the application of high-temperature water-soluble silk is cleverly combined with double-twist technology. A special spinning and single yarn sizing process is used to accurately embed the water-soluble silk into the core of the yarn. When the prepared Roulan yarn is used in specific applications, a high-temperature dyeing process is involved. The high temperature conditions in this process cause the water-soluble silk to dissolve, and the yarn becomes hollow. The fibers quickly absorb water and expand to make the fabric soft and fluffy, and the fabric becomes softer and softer with increasing number of uses. The key technology in the doubling process is that when the two single yarns are twisted, the twist direction of the ply yarn is opposite to that of the single yarn. The single yarn is twisted in S-twist and the ply yarn is twisted in Z-twist. Because the single yarns are sizing, they will not untwist due to the opposite twist direction during the plying process. The appropriate twist is the key to this process. If the twist is too small, there will be many residual twists during the subsequent back-twist, which will make the hand feel poor. If the twist is too large, the fibers will be untwisted during the back-twist, resulting in low fabric strength and affecting the service life. This solves the problem of balancing fabric water absorption, softness, yarn strength and product durability in the existing technology.

[0120] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0121] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing Roulan yarn, characterized in that the steps include: The Roulan yarn is prepared from long-staple cotton, fine-staple cotton and water-soluble filament as raw materials through the processes of blowing, carding, pre-drawing, sliver winding, combing, second drawing, vortex spinning, automatic winding, sizing and doubling.

2. The preparation method according to claim 1, wherein The mass ratio of the long-staple cotton, fine-staple cotton and water-soluble filament is 6:3:1; and / or, the fiber length of the long-staple cotton is not less than 38 mm; and / or, the fiber length of the fine-staple cotton is not less than 28 mm; And / or, the long-staple cotton and the fine-staple cotton have a breaking strength of ≥29 cN / tex, an impurity content of ≤2.5%, and a moisture regain of 8-9%; And / or, the water-soluble filaments are polyvinyl alcohol water-soluble filaments with an alcoholysis degree of 85-97 mol% and a dissolution temperature of 80-90°C.

3. The preparation method according to claim 1, wherein The parameters of the cotton cleaning machine are as follows: the beater speed of the plucker is 500 r / min, the impurity removal efficiency is 60%-70%, and the lap quantitative deviation is ≤1.2%; And / or, the carding parameters are: cylinder speed of 310 rpm, doffer speed of 20 rpm, licker-in-cylinder distance of 0.25 mm, card sliver basis weight of 18-25 g / 5 m, pure cotton card sliver neps ≤80 / g, and short lint rate ≤12%.

4. The preparation method according to claim 1, wherein The parameters of the pre-drawing are as follows: the number of slivers to be drawn is 8; the total drafting ratio is 6 times, the back zone drafting is 1.2 times; the roller spacing is 28-30mm; the pre-drawing sliver quantitative deviation is ≤1.0%, and the CV value of the sliver is ≤4.5%; And / or, the parameters of the strip roll are: the number of strips to be combined is 18 pre-drawn strips; the strips are wound into a roll, 20 strips x 3 layers, and the strip roll density is 0.4g / cm 3 ; Roller speed is 120m / min; Basis deviation ≤0.6%.

5. The preparation method according to claim 1, wherein The combing parameters are: cylinder speed 350r / min; cotton drop rate 19%; cylinder card clothing density 320 needles / m 2 ;The basis weight of combed sliver is 18g / 5m; And / or, the parameters of the second drawing are: the number of slivers is 6; the total drafting multiple is 6 times, the back zone drafting is 1.05 times; the roller spacing is 26-28mm; the quantitative deviation of the sliver after the second drawing is ≤0.5%, and the CV value of the sliver is ≤3.5%.

6. The preparation method according to claim 1, wherein The parameters of the vortex spinning are as follows: spindle speed of 4500 rpm; nozzle air pressure of 0.58 MPa; twist direction of S twist; yarn thinning to 32 count; twist of 58-60 twists / m.

7. The preparation method according to claim 1, wherein The parameters of the automatic winding are as follows: winding speed is 1500m / min; defect removal range is thick places +50% to +200%, thin places -30% to -70%, and neps +20% to +50%; winding density of the yarn is 0.39-0.45g / cm 3 .

8. The preparation method according to claim 1, wherein The parameters of the sizing yarn are as follows: sizing concentration of 5.5wt%; sizing rate of 5%; sizing tank temperature of 40-45°C; drying temperature of 60-70°C; yarn elongation ≤1.3%; And / or, the parameters of the double twisting and doubling are: the number of doubling yarns is 2 spun yarns; the double twisting degree is 58 twists / m; the tension uniformity of the winding tension is ≤4%; the twist direction of the strands is Z twist.

9. A Roulan yarn, characterized in that: The Roulan yarn is prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the Roulan yarn according to claim 9 in the preparation of home textiles.