Low-twist compact siro twist spinning yarn, preparation method thereof and process for producing knitted fabric by adopting low-twist compact siro twist spinning yarn

Abstract

The invention belongs to the technical field of textile dyeing and finishing, and particularly relates to a low-twist compact siro twisted spinning yarn, a preparation method thereof and a process for producing knitted fabric by adopting the low-twist compact siro twisted spinning yarn. Comprising the following procedures of raw cotton preparation, blowing, cotton carding, pre-drawing, sliver lap forming, combing, sliver lap forming, combing, drawing, roving, spinning and spooling. In the roving and spinning procedures, the low-twist compact siro twisted spun yarn is prepared in a compact spinning mode, a siro spinning mode and a twisted spinning mode in sequence. The yarn is improved, siro spinning and twist spinning are overlaid on the basis of compact spinning, the obtained fabric is softer in hand feeling, the yarn formed by combining the three spinning modes is used for the knitted fabric, and the advantages of the raw material end are all reflected in the knitted fabric.

Description

Technical Field

[0001] The invention belongs to the technical field of textile dyeing and finishing, and particularly relates to a low-twist compact siro-twist yarn and a preparation method thereof, as well as a process for producing knitted fabrics using the same. Background Art

[0002] As people's requirements for the comfort and softness of knitted fabrics are getting higher and higher, the use of various auxiliaries in the post-processing process can no longer further improve the comfort and softness of the fabric. Therefore, it is necessary to improve the yarn processing of the raw material end to further improve the softness of the fabric.

[0003] Due to technical limitations, the currently mainstream ring-spun and siro-spun yarns on the market struggle to simultaneously meet the requirements of low twist, high strength, and excellent weaving properties. Ring-spun yarns, constrained by raw material selection and process characteristics, require a high twist coefficient (340-370) to ensure yarn strength. This results in yarn stiffness and a tendency to backtwist during weaving, impacting weaving efficiency. Furthermore, excessive yarn twist can create defects such as "braids" on the fabric surface, resulting in substandard fabric appearance. High-twist yarns used in knitted fabrics can result in a stiffer feel due to the raw material. While siro-spun yarns improve yarn evenness and strength through double roving feeding, raw material limitations prevent them from achieving low twist. The twist coefficient is generally between 350-380. Since the twist coefficient is largely the same as ring-spun yarns, the fabric's softness is similar to that of ring-spun yarns, offering limited improvement in softness.

[0004] Therefore, it is urgent to develop a yarn with low twist coefficient, high strength and soft feel. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a low-twist compact siro-twist spun yarn, which can maintain high strength under the premise of low twist coefficient, and at the same time has a fluffy and soft hand feel and uniform yarn length.

[0006] The invention also provides a preparation method thereof, which is scientific, reasonable and suitable for large-scale production.

[0007] The invention also provides a process for producing knitted fabrics using the same, which has wide adaptability.

[0008] The low-twist compact siro-twist spinning yarn of the present invention is prepared by sequentially compact spinning, siro-spinning and twist-twist spinning.

[0009] The twist coefficient of the yarn is 240-300.

[0010] The yarn count of the yarn is 30 Nes to 60 Nes.

[0011] The method for preparing the low-twist compact siro-twist yarn of the present invention comprises the following steps: raw cotton → cleaning → carding → pre-drawing → slivering and winding → combing → slivering and winding → combing → drawing → roving → spun yarn → winding;

[0012] In the roving process, the sliver is drafted by a drafting device to produce roving;

[0013] In the spinning process, two coarse yarns are fed in parallel to obtain compact siro-spun yarn through a siro-spinning method. At the yarn output end of the spinning frame, a transverse friction force is applied to the compact siro-spun yarn through a transverse friction mechanism perpendicular to the output direction of the compact siro-spun yarn, thereby obtaining a low-twist compact siro-twist spun yarn.

[0014] The lateral friction mechanism includes several clamping devices arranged in parallel and spaced apart and active driving mechanisms located at both ends of the clamping devices. The clamping device includes a driven wheel, a separating shaft, and a driven wheel arranged in sequence from top to bottom. The driven wheel, the separating shaft, and the driven wheel are connected to the connecting plate through a rotating shaft, and the bottom of the connecting plate is connected to the fixed plate; the belt is passed between the upper part of the separating shaft and the driven wheel, and between the lower part of the separating shaft and the driven wheel. The active driving mechanism includes a driving wheel, the rotating shaft of the driving wheel is connected to the driving end of the motor, and the belt is a continuous ring belt, with both ends of the belt passing around the driving wheel.

[0015] The separating shaft separates the parallel upper and lower belts by a distance of 0.5-1 cm, preferably 1 cm. Too large a distance will cause an increase in yarn breakage and a decrease in spinning efficiency. The compact siro-spun yarn is perpendicular to the movement direction of the belt and is wound downward in an "S" shape along the outer diameter of the upper and lower belts.

[0016] The outer edge of the driven wheel is provided with a first wheel baffle, and the outer edge of the driving wheel is provided with a second wheel baffle, which can effectively prevent the belt from falling off the driving wheel or the driven wheel when the driving wheel and the driven wheel rotate horizontally.

[0017] The fixed plate is connected to the lower body of the drafting mechanism at the yarn output end of the spinning frame through a fixed connecting mechanism.

[0018] Preferably, the fixed connection mechanism is a screw, which passes through a threaded hole provided on the fixed plate and is threadedly connected to the spinning frame body.

[0019] The present invention performs another round of combing on the basis of traditional combing, thereby further improving the uniformity of the fibers. At the same time, there are fewer impurities and short fibers in the slivers, which makes a more adequate preparation for the subsequent yarn quality. In the spinning process, the spinning methods of sirospinning and twist-tospinning are superimposed on the traditional compact spinning. In this way, the advantages of compact spinning, sirospinning and twist-tospinning appear on the yarn at the same time. In this way, the yarn not only has the characteristics of less hairiness of compact spinning, but also has the characteristics of good yarn uniformity of sirospinning and low twist and softness of twist-tospinning.

[0020] Raw cotton selection:

[0021] For spinning Ne 30-40 yarn, fine-staple cotton with a fiber length of 25-31mm and a fiber strength of 26-36cN / tex is used. For spinning Ne 50-60 yarn, long-staple cotton with a fiber length of 33-40mm and a fiber strength of 36-46cN / tex is used.

[0022] Preferably, the cotton is Xinjiang long-staple cotton, SUPIMA cotton, or Egyptian long-staple cotton with a fiber length greater than 36 mm and a fiber strength greater than 40 cm; or the cotton is Xinjiang fine-staple cotton, Australian fine-staple cotton, American fine-staple cotton, or Brazilian fine-staple cotton with a fiber length greater than 28 mm and a fiber strength greater than 28 cm.

[0023] The cotton cleaning process: the grabbing depth is 0.0-1.3mm, the working speed is 16-20r / min, the beater speed is 1000-1200r / min, and the blade extends -3mm.

[0024] The carding process has an output of 15-20 kg / h, a cylinder speed of 400-450 r / min, a licker-in speed of 800-1100 r / min, a flat plate speed of 90-110 mm / min, and a wet weight of 17-22 g / 5 m.

[0025] The pre-drawing process: the sliver delivery speed is 300-500m / min, the post-drafting ratio is 1.1-1.2 times, the number of slivers is 6-8, the drafting ratio is 5-8 times, and the wet weight is 17-22g / 5m.

[0026] The strip winding process is as follows: the strip delivery speed is 70-100m / min, the post-drafting ratio is 1.05-1.15 times, the number of strips to be combined is 20-24, the drafting ratio is 1.5-1.7 times, and the wet weight is 55-65g / m.

[0027] The combing process includes: a cylinder nip speed of 350-400 times / min, a back drafting multiple of 1.05-1.15 times, a drafting multiple of 6-12 times, a backward feeding method, a feeding length of 4.3 mm, a cotton drop spacing of 12.5 mm, a wet weight of 17-24 g / 5 m, and a cotton drop rate of 15-17%.

[0028] The drawing process is as follows: the sliver delivery speed is 450-500m / min, the post-drafting ratio is 1.15-1.25 times, the number of slivers is 6-8, the drafting ratio is 5-8 times, and the wet weight is 17-24g / 5m.

[0029] The roving process comprises: a spindle speed of 900-1100 r / min, a twist of 0.9-2.1 T / in, a post-drafting multiple of 1.1-1.2 times, a drafting multiple of 6-12 times, and a wet weight of 2.8-6.0 g / 10 m.

[0030] The spinning process has a speed of 14,000-16,000 r / min, a twist coefficient of 240-300, a post-draft ratio of 1.1-1.3 times, a draft ratio of 30-70 times, a wet weight of 9.7-19.5 g / 1000 m, and a belt speed of 30-50 m / min.

[0031] The winding process: the speed is 900-1200m / min, and the tension is controlled to be 140-200cn.

[0032] The process for producing knitted fabrics from low-twist compact siro-twist yarns of the present invention comprises the following steps:

[0033] Weaving → singeing → dyeing → dyeing and drying → pre-shrinking → stentering.

[0034] The weaving process adopts a large circular machine and 24-40 needle knitting.

[0035] The weaving process includes a plain weft stitch and an interlock weave.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1) The present invention improves the yarn by superimposing siro spinning and twist spinning on the basis of compact spinning, so that the resulting fabric feels softer. The yarn composed of the three spinning methods is used for knitted fabrics, and the advantages of the raw material end are all reflected in the knitted fabrics.

[0038] 2) In order to produce high-quality yarn that is more suitable for knitted fabrics, the present invention makes coordinated improvements in raw material selection and spinning methods. From the perspective of raw material selection, 30-40 fine-staple cotton with a fiber length of 25-31 mm and a fiber strength of 26-36 cn / tex, or 50 long-staple cotton with a fiber length of 33-40 mm and a fiber strength of 36-46 cn / tex is selected as the raw cotton; from the perspective of spinning methods, a double combing + compact siro-twist spinning process is adopted to improve the uniformity and cohesion of the fibers, and to increase the strength of the yarn, so that the yarn count can be 30 to 60 Ne. In the weaving process, 24 to 40 needles are used to knit and adjust the appropriate weaving line length; this solves the problems of weaving twist and fabric softness, and can meet diversified market demands.

[0039] 3) This invention, through the modification of the spinning frame, adds a lateral force to the yarn output section, causing friction on the yarn, achieving the twist-spun style of yarn. This allows the yarn to have a lower twist while maintaining the same strength. While the twist coefficient of ordinary yarn is between 340-370, the twist coefficient of twist-spun yarn can be between 240-300, thus solving the problem of backtwist during weaving. Since the yarn strength is basically the same as the original yarn strength, weaving efficiency is guaranteed during the weaving process, while also making the woven fabric more soft. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a front view of the lateral friction mechanism of the present invention;

[0041] Figure 2 A side view of the clamping device according to the present invention;

[0042] Figure 3 A side view of the active drive mechanism of the present invention;

[0043] Figure 4 This is a diagram of the state of compact siro-spun yarn passing through the belt.

[0044] In the picture:

[0045] 1. Driven pulley; 2. First pulley baffle; 3. Separator shaft; 4. Belt; 5. Connecting plate; 6. Fixed plate; 7. Screw; 8. Driving pulley; 9. Second pulley baffle; 10. Motor; 11. Compact siro-spun yarn. DETAILED DESCRIPTION

[0046] The present invention will be further described below with reference to the following examples, but the protection scope of the present invention is not limited thereto.

[0047] Unless otherwise specified, all raw materials used in the examples are commercially available.

[0048] The auxiliary agent:

[0049] PH-X, HP-S, PH-N, EZ-B: Zibo Lurui Fine Chemical Co., Ltd.

[0050] 575: Guangdong Jiahe Chemical Co., Ltd.

[0051] JAS: Qingdao Ounosi Industry and Trade Co., Ltd.;

[0052] GS-8816A: Weifang Gaosheng Chemical Co., Ltd.

[0053] SQ-B: Zibo Lurui Fine Chemical Co., Ltd.;

[0054] DQ-1155: Shandong Demei Chemical Co., Ltd.

[0055] The lateral friction mechanism used in the following specific embodiments is as follows: Figure 1-4 As shown, it includes several clamping devices arranged in parallel and spaced apart and an active driving mechanism located at both ends of the clamping device, the clamping device includes a driven wheel 1, a separating shaft 3, and a driven wheel 1 arranged in sequence from top to bottom, the driven wheel 1, the separating shaft 3, and the driven wheel 1 are connected to the connecting plate 5 through a rotating shaft, and the bottom of the connecting plate 5 is connected to the fixed plate 6; the belt 4 is passed between the upper part of the separating shaft 3 and the driven wheel 1, and between the lower part of the separating shaft 3 and the driven wheel 1, the active driving mechanism includes a driving wheel 8, the rotating shaft of the driving wheel 8 is connected to the driving end of the motor 10, the belt 4 is a continuous annular belt 4, and both ends of the belt 4 pass around the driving wheel 8.

[0056] The separating shaft 3 separates the parallel upper and lower belts 4 by a distance of 1 cm. The compact siro-spun yarn 11 is perpendicular to the movement direction of the belt 4 and moves downward in an "S" shape along the outer diameter of the upper and lower belts 4 to perform the winding process.

[0057] The outer edge of the driven wheel 1 is provided with a first wheel baffle 2, and the outer edge of the driving wheel 8 is provided with a second wheel baffle 9. This can effectively prevent the belt 4 from falling off the driving wheel 8 or the driven wheel 1 when the driving wheel 8 and the driven wheel 1 rotate horizontally.

[0058] The fixed plate 6 is connected to the lower body of the drafting mechanism at the yarn output end of the spinning frame through a fixed connection mechanism.

[0059] Preferably, the fixed connection mechanism is a screw 7, which passes through a threaded hole provided on the fixed plate 6 and is threadedly connected to the spinning frame body.

[0060] Example 1

[0061] The method for preparing the low-twist compact siro-twist yarn comprises the following steps: raw cotton → cleaning → carding → pre-drawing → slivering and winding → combing → slivering and winding → combing → drawing → roving → spun yarn → winding;

[0062] The raw cotton is 100% high-quality long-staple cotton with a micronaire value of 3.7, a fiber length of 37 mm, a uniformity of 88%, and a fiber strength of 40.5 cN / tex.

[0063] The cotton cleaning process: the grabbing depth is 1.1mm, the working speed is 18r / min, the beater speed is 1100r / min, and the blade extends -3mm.

[0064] The carding process has the following characteristics: output of 16 kg / h, cylinder speed of 420 r / min, licker-in speed of 900 r / min, flat speed of 100 mm / min, and wet weight of 20 g / 5 m.

[0065] The pre-drawing process: the sliver delivery speed is 400m / min, the post-drafting ratio is 1.15 times, the number of slivers drawn together is 6, the drafting ratio is 6 times, and the wet weight is 20g / 5m.

[0066] The strip winding process is as follows: the strip delivery speed is 70m / min, the post-drafting ratio is 1.1 times, the number of strips wound together is 24, the drafting ratio is 1.6 times, and the wet weight is 60g / m.

[0067] The combing process includes: a cylinder nip of 350 times / min, a back drafting multiple of 1.05 times, a drafting multiple of 10 times, a feeding method of backward feeding, a feeding length of 4.3 mm, a cotton drop spacing of 12.5 mm, a wet weight of 17 g / m, and a cotton drop rate of 16.5%.

[0068] The drawing process is as follows: the delivery speed is 450m / min, the post-drafting ratio is 1.2 times, the number of slivers is 6, the drafting ratio is 5.8 times, and the wet weight is 17.5g / 5m.

[0069] The roving process includes: the sliver is drafted by a drafting device to produce the roving; the spindle speed is 1000 r / min, the twist is 1.279 T / in, the post-drafting multiple is 1.13 times, the drafting multiple is 11.5 times, and the wet weight is 2.95 g / 10m.

[0070] The spinning process comprises the following steps: feeding two rovings in parallel to obtain a compact siro-spun yarn through a siro-spinning method; applying a transverse friction force to the compact siro-spun yarn at a yarn output end of the spinning frame, perpendicular to the output direction of the compact siro-spun yarn, through a transverse friction mechanism, to obtain a low-twist compact siro-twist yarn; the spinning process comprises the following steps: a speed of 15,000 r / min, a twist of 21.5 T / in, a twist coefficient of 290, a post-draft ratio of 1.15 times, a draft ratio of 50 times, a wet weight of 11.7 g / 1000 m, and a belt speed of 35 m / min.

[0071] The winding process: the speed is 1100m / min, and the tension is controlled at 170cn.

[0072] The obtained low-twist compact siro-twist yarn had the following specifications: evenness: 10.3, 200% cotton neps (particles / km): 16, strength (cn): 365.6, hairiness (N / 10M) above 3 mm: 33. Yarn count: 50 Ne.

[0073] The process for producing knitted fabrics from low-twist compact siro-twist yarns comprises the following steps:

[0074] Weaving → singeing → dyeing → dyeing and drying → pre-shrinking → stentering.

[0075] The weaving process adopts a large circular machine and 32 stitches; the weaving structure is an interlocking rib structure, and the length of the 100-loop thread is 25.5 mm.

[0076] Singeing: speed 70m / min, flame intensity 12mbar;

[0077] Dyeing: The overflow dyeing machine is used for dyeing. The dyeing process is pre-treatment - dyeing - post-treatment - softening in the vat;

[0078] The formula of the pretreatment process liquid is as follows: anti-wrinkle agent JAS 3g / L, softener GS-8816A2.5g / L, SQ-B1.2g / L, refining agent DQ-1155 2g / L, hydrogen peroxide stabilizer HP-S2.8g / L, NaOH 4.5g / L, H2O2 8g / L, neutralizing acid PH-N 1g / L, deoxygenase EZ-B 0.2g / L are added to the bath, the treatment temperature is 105℃, and the treatment time is 50min.

[0079] Dyeing process conditions: reactive dyes were used for dyeing, 80 g / L of sodium sulfate and 18 g / L of soda ash were added, and the dyeing temperature was 60°C.

[0080] Post-treatment soaping process conditions: soaping temperature 100°C, soaping time 15 min, soaping agent dosage 2 g / L.

[0081] Add soft water to the tub and adjust the pH value to 6.5. Add hydrophilic softener GS-8816A at a concentration of 3%. Maintain the water temperature at 55°C for 20 minutes. Remove the damp cloth from the tub.

[0082] Dyeing and drying: pressure 30N, speed 40m / min, overfeed 40%, drying room temperature 140℃;

[0083] Pre-shrinkage: speed 30m / min, rubber blanket temperature 100℃, wool blanket temperature 100℃;

[0084] Stretching: speed 40m / min, pressure 30N, overfeed 35%, additives PH-X: 2g / L, 575: 100g / L.

[0085] Example 2

[0086] The yarn used is the same as in Example 1.

[0087] The process for producing knitted fabrics from low-twist compact siro-twist yarns comprises the following steps:

[0088] Weaving → singeing → pre-setting → dyeing → dyeing and drying → tentering → tentering A cutting.

[0089] The weaving process adopts a large circular machine, 28 stitches; the weft stitch is a plain stitch, and the length of the hundred-loop thread is 24 mm.

[0090] Singeing: speed 70m / min, flame intensity 12mbar;

[0091] Preset type: speed 40m / min, drying room temperature 140℃, overfeed 30%;

[0092] Dyeing: Dyeing was performed using an overflow dyeing machine. The dyeing process was pretreatment-dyeing-posttreatment-softening in a vat. The pretreatment-dyeing-posttreatment was the same as in Example 1. The pH value of the soft water in the vat was adjusted to 6.5. A hydrophilic softener GS-8816A was added at a concentration of 2.5%. The water temperature was maintained at 55° C. for 18 minutes. The wet cloth was removed from the vat with water.

[0093] Dyeing and drying: pressure 30N, speed 40m / min, overfeed 35%, drying room temperature 140℃;

[0094] Stentering: speed 25m / min, pressure 30N, overfeed 35%, drying room temperature 150℃;

[0095] Stenter A cutting: speed 40m / min, pressure 30N, overfeed 30%, drying room temperature 140℃, auxiliary agent PH-X: 3g / L.

[0096] Example 3

[0097] The method for preparing the low-twist compact siro-twist yarn comprises the following steps: raw cotton → cleaning → carding → pre-drawing → slivering and winding → combing → slivering and winding → combing → drawing → roving → spun yarn → winding;

[0098] The raw cotton is 100% high-quality fine-staple cotton with a micronaire value of 4.0, a fiber length of 28 mm, a uniformity of 88%, and a fiber strength of 29 cN / tex.

[0099] The cotton cleaning process, carding process, pre-drawing process, strip and waving process, combing process, and drawing process are the same as those in Example 1.

[0100] The roving process includes: the sliver is drafted by a drafting device to produce the roving; the spindle speed is 1000 r / min, the twist is 1.42 T / in, the post-drafting multiple is 1.15 times, the drafting multiple is 10.9 times, and the wet weight is 3.2 g / 10m.

[0101] The spinning process comprises the following steps: feeding two rovings in parallel to obtain a compact siro-spun yarn through a siro-spinning method; applying a transverse friction force to the compact siro-spun yarn at a yarn output end of the spinning frame, perpendicular to the output direction of the compact siro-spun yarn, through a transverse friction mechanism, to obtain a low-twist compact siro-twist yarn; the spinning process comprises the following steps: a speed of 15,000 r / min, a twist of 18 T / in, a twist coefficient of 270, a post-draft multiple of 1.15 times, a draft multiple of 43.8 times, a wet weight of 14.6 g / 1000 m, a belt speed of 35 m / min, and a yarn count of 40 Nes.

[0102] The winding process is the same as in Example 1.

[0103] The obtained low-twist compact siro-twist yarn has the following indicators: evenness: 10.21, 200% cotton neps (grains / KM): 12, strength (cn): 320.6, and hairiness above 3 mm (N / 10M): 13.

[0104] The process for producing knitted fabrics from low-twist compact siro-twist yarns comprises the following steps:

[0105] Weaving → singeing → dyeing → dyeing and drying → pre-shrinking → stentering.

[0106] The weaving process adopts a large circular machine and 32 stitches; the weaving structure is an interlocking rib structure, and the length of the 100-loop thread is 27.5 mm.

[0107] The post-processing is the same as that in Example 1.

[0108] Examples 1-3 were tested, and the test data are as follows:

[0109] Table 1 Test data table

[0110]

[0111] Weight standard: ISO 3801:1977;

[0112] Width standard: ISO 22198:2006;

[0113] Shrinkage standard: ISO 6330:2021;

[0114] Bursting strength standard: ISO 13938-1:2004;

[0115] pH value standard: ISO 3071:2020;

[0116] Pilling standard: ISO 12945-2:2020;

[0117] Internal control standard for hand feel: Three people touch the hand feel, give a score, and take the average value. The full score is five points. The higher the score, the better the hand feel.

[0118] Comparative Example 1

[0119] Preparation of ring spun yarn includes the following steps: raw cotton → cleaning → carding → pre-drawing → striping and winding → combing → striping and winding → combing → drawing → roving → spun yarn → winding;

[0120] The raw cotton is 100% high-quality long-staple cotton with a micronaire value of 3.7, a fiber length of 37 mm, a uniformity of 88%, and a fiber strength of 40.5 cN / tex.

[0121] The cotton cleaning process: the grabbing depth is 1.1mm, the working speed is 18r / min, the beater speed is 1100r / min, and the blade extends -3mm.

[0122] The carding process has the following characteristics: output of 16 kg / h, cylinder speed of 420 r / min, licker-in speed of 900 r / min, flat speed of 100 mm / min, and wet weight of 20 g / 5 m.

[0123] The pre-drawing process: the sliver delivery speed is 400m / min, the post-drafting ratio is 1.15 times, the number of slivers drawn together is 6, the drafting ratio is 6 times, and the wet weight is 20g / 5m.

[0124] The strip winding process is as follows: the strip delivery speed is 70m / min, the post-drafting ratio is 1.1 times, the number of strips wound together is 24, the drafting ratio is 1.6 times, and the wet weight is 60g / m.

[0125] The combing process includes: a cylinder nip of 350 times / min, a back drafting multiple of 1.05 times, a drafting multiple of 10 times, a feeding method of backward feeding, a feeding length of 4.3 mm, a cotton drop spacing of 12.5 mm, a wet weight of 17 g / m, and a cotton drop rate of 16.5%.

[0126] The drawing process is as follows: the delivery speed is 450m / min, the post-drafting ratio is 1.2 times, the number of slivers is 6, the drafting ratio is 5.8 times, and the wet weight is 17.5g / 5m.

[0127] The roving process includes: a spindle speed of 1000 r / min, a twist of 1.415 T / in, a post-drafting multiple of 1.13 times, a drafting multiple of 7 times, and a wet weight of 5 g / 10 m.

[0128] The spinning process has the following characteristics: speed of 15000 r / min, twist of 27 T / in, twist coefficient of 363, post-drafting multiple of 1.15 times, drafting multiple of 42 times, and wet weight of 11.7 g / 1000 m.

[0129] The winding process: the speed is 1100m / min, and the tension is controlled at 170cn.

[0130] Comparative Example 2

[0131] Preparation of siro-spun yarn includes the following steps: raw cotton → cleaning → carding → pre-drawing → slivering and winding → combing → slivering and winding → combing → drawing → roving → spun yarn → winding;

[0132] The cotton cleaning process, carding process, pre-drawing process, strip and winding process, combing process, drawing process, and winding process are the same as those in Example 1.

[0133] The roving process includes: a spindle speed of 1000 r / min, a twist of 1.62 T / in, a post-drafting multiple of 1.13 times, a drafting multiple of 11.5 times, and a wet weight of 3 g / 10 m.

[0134] The spinning process includes: a spindle speed of 1500 r / min, a twist of 27 T / in, a twist coefficient of 363, a post-drafting multiple of 1.15 times, a drafting multiple of 52 times, and a wet weight of 11.7 g / 1000 m.

[0135] Comparative Example 3

[0136] The process is the same as in Example 1, except that it is a single combing process;

[0137] Conventional spinning process:

[0138] Blowing → Carding → Pre-drawing → Slivering and winding → Combing → Drawing → Coarse yarn → Slivering → Winding.

[0139] Comparative Example 4

[0140] Conventional raw material specifications: the raw cotton is selected from 100% high-quality long-staple cotton, with a micronaire value of 3.5, a fiber length of 32 mm, a uniformity of 86%, and a fiber strength of 35 cN / tex.

[0141] All spinning processes are the same as in Example 1.

[0142] The yarns prepared in Comparative Examples 1-4 and Example 1 were tested, and the test results are shown in Table 2 below:

[0143] Table 2 Yarn test results

[0144]

[0145]

Claims

1. A low twist compact siro-twist spun yarn, characterized in that: The yarn is obtained by compact spinning, siro spinning and twist spinning in sequence.

2. The low twist compact siro-twist yarn according to claim 1, characterized in that: The twist coefficient of the yarn is 240-300.

3. The low twist compact siro-twist yarn according to claim 1, characterized in that: The yarn count of the yarn is 30 Nes to 60 Nes.

4. A method for preparing the low-twist compact siro-twist yarn according to any one of claims 1 to 3, characterized in that: The process includes: raw cotton → cleaning → carding → pre-drawing → slivering and winding → combing → slivering and winding → combing → drawing → roving → spun yarn → winding; In the roving process, the sliver is drafted by a drafting device to produce roving; In the spinning process, two coarse yarns are fed in parallel to obtain a compact siro-spun yarn (11) through a siro-spinning method. At the yarn output end of the spinning machine, a transverse friction force is applied to the compact siro-spun yarn (11) perpendicular to the output direction of the compact siro-spun yarn through a transverse friction mechanism, thereby obtaining a low-twist compact siro-twist spun yarn.

5. The method for preparing low-twist compact siro-twist yarn according to claim 4, characterized in that: The transverse friction mechanism comprises a plurality of clamping devices arranged in parallel and spaced apart and an active driving mechanism located at both ends of the clamping devices, wherein the clamping device comprises a driven wheel (1), a separation shaft (3), and a driven wheel (1) arranged in sequence from top to bottom, wherein the driven wheel (1), the separation shaft (3), and the driven wheel (1) are connected to a connecting plate (5) via a rotating shaft, and the bottom of the connecting plate (5) is connected to a fixed plate (6); a belt (4) is passed through between the upper portion of the separation shaft (3) and the driven wheel (1), and between the lower portion of the separation shaft (3) and the driven wheel (1); the active driving mechanism comprises a driving wheel (8), the rotating shaft of the driving wheel (8) is connected to the driving end of the motor (10), and the belt (4) is a continuous annular belt (4), and both ends of the belt (4) pass around the driving wheel (8).

6. The method for preparing low-twist compact siro-twist yarn according to claim 5, characterized in that: The separation shaft (3) separates the upper and lower parallel belts (4), and the compact siro-spun yarn (11) is perpendicular to the movement direction of the belt (4) and moves downward along the outer diameter of the upper and lower belts (4) in an "S" shape to perform the winding process.

7. The method for preparing low-twist compact siro-twist yarn according to claim 4, characterized in that: The raw cotton is fine-staple cotton with a fiber length of 25-31 mm and a fiber strength of 26-36 cN / tex, or long-staple cotton with a fiber length of 33-40 mm and a fiber strength of 36-46 cN / tex.

8. A process for producing knitted fabrics using the low-twist compact siro-twist yarn according to any one of claims 1 to 3, characterized in that: The process includes the following steps: Weaving → singeing → dyeing → dyeing and drying → pre-shrinking → stentering.

9. The process for producing knitted fabrics using low-twist compact siro-twist yarn according to claim 8, characterized in that: The weaving process adopts a large circular machine and 24-40 needle knitting.

10. The process for producing knitted fabrics using low-twist compact siro-twist yarn according to claim 8, characterized in that: The weaving process includes a plain weft stitch and an interlock weave.

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