A method for producing low cost pure cotton yarn

Abstract

The application discloses a low-cost pure cotton yarn production method, which uses fine-fiber cotton and long-fiber cotton as raw materials, controls the distribution of the two fibers in the yarn body in the spinning process, reduces the long-fiber cotton fiber consumption, realizes the production of high-quality pure cotton yarn, and further provides a low-cost pure cotton yarn production method. The long-fiber cotton / fine-fiber cotton core-spun roving with long-fiber cotton as the outer wrapping fiber and fine-fiber cotton as the center is prepared by adopting the core-spun process in the roving process; the long-fiber cotton / fine-fiber cotton sliver with long-fiber cotton fibers mainly located at the outside and the mixed long-fiber cotton and fine-fiber cotton fibers at the center is prepared by adopting the four-rooler three-zone draft structure in the spinning process; the pure cotton yarn with long-fiber cotton fibers mainly located at the outside and the mixed long-fiber cotton and fine-fiber cotton fibers at the center is prepared by adopting the twisting process; and the distribution of the two fibers in the yarn body is controlled, so that the low-cost production of the pure cotton yarn with excellent appearance effect and yarn quality is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new yarns, in particular to a production method of low-cost pure cotton yarn. BACKGROUND

[0002] With the development of social economy, people's living standards are improving, and for clothing textiles, in addition to pursuing wearing comfort, more and more attention is paid to fashion and functionality, and unique style and various functions such as antibacterial and antistatic functions are pursued. In order to meet the needs of consumers, it is an important task for the textile industry to constantly develop new yarns and fabrics. With the development of science and technology, the competition in the textile market is becoming more and more fierce, and various manufacturers are constantly developing towards high-end, high-grade, good technology content and high added value in order to maximize profits.

[0003] Pure cotton yarn is the most common type of yarn and the most mature spinning process at present. Natural cotton fibers are used as raw materials in pure cotton yarn production. Cotton fibers generally include fine lint cotton fibers and long lint cotton fibers. The average length of fine lint cotton fibers is generally less than 30 mm, and the length dispersion is large. Long lint cotton has excellent quality, with soft and long fibers, generally 33-39 mm in length, and up to 64 mm in length, 7000-8500 meters per gram in fineness, 15-16 microns in width, high strength of 4-5 grams per root, breaking length of 33-40 kilometers, and more than 80-120 turns per centimeter. Therefore, it is generally suitable for the production of high-quality pure cotton yarn. However, long lint cotton fibers are expensive, thereby increasing the production cost of the corresponding yarn. SUMMARY

[0004] The purpose of the present application is to provide a production method of low-cost pure cotton yarn, which uses fine lint cotton fibers and long lint cotton fibers as raw materials to realize low-cost production of pure cotton yarn with excellent appearance effect and yarn quality.

[0005] The present application provides a production method of low-cost pure cotton yarn, comprising the following steps:

[0006] First step: cotton blending, fine lint cotton is selected from Shandong Jinxiang cotton with an average length of 28.3 mm and an average micronaire value of 4.3, Hebei Dongguang cotton with an average length of 28.7 mm and an average micronaire value of 5.1, and Anhui Wuhua cotton with an average length of 27.2 mm and an average micronaire value of 4.9, and 6 bales of Shandong Jinxiang cotton, 6 bales of Hebei Dongguang cotton and 1 bale of Anhui Wuhua cotton are used in each disc, and the discharge order of the three cotton bales in each disc is:

[0007] The two circles of the disc are respectively arranged with two Shandong Jinxiang cotton bales and two Hebei Dongguang cotton bales, and the two kinds of cotton bales are arranged at intervals, one Anhui Wuxi cotton bale is arranged along the outer circle of the center of the disc, the outer circle of the disc is arranged with four Shandong Jinxiang cotton bales and four Hebei Dongguang cotton bales, and the two kinds of cotton bales are arranged at intervals, and the long-staple cotton is selected from 100% Xinjiang long-staple cotton fibers;

[0008] The second step is carding, and the selected fine-staple cotton is prepared into fine-staple cotton sliver through opening, carding and combing, and the long-staple cotton is prepared into long-staple cotton sliver through carding and combing;

[0009] The third step is long-staple cotton combing, and the long-staple cotton sliver prepared in the second step is sequentially prepared into a combed sliver with excellent uniformity through sliver winding and lap winding, and the combed sliver is prepared into long-staple cotton combed sliver through combing;

[0010] The fourth step is doubling, and the fine-staple cotton sliver prepared in the second step is prepared into fine-staple cotton slub through three-doubling, and the long-staple cotton combed sliver prepared in the third step is prepared into long-staple cotton slub through two-doubling;

[0011] The fifth step is fine-staple cotton roving, and the fine-staple cotton slub prepared in the fourth step is prepared into fine-staple cotton roving through draft and twisting winding of the drafting system of the roving frame;

[0012] The sixth step is long-staple cotton / fine-staple cotton core-spun roving, and the long-staple cotton slub prepared in the fourth step and the fine-staple cotton roving prepared in the fifth step are prepared into long-staple cotton roving as outer package roving and fine-staple cotton roving as core yarn through the roving frame, and the long-staple cotton slub is fed into the drafting system of the roving frame by the back roller of the roving frame, and the long-staple cotton slub is obtained through the drafting action of the drafting system, and is output by the front roller under the pressing of the front roller, and the fine-staple cotton roving on the roving drum is first pressed by the pressing roller, and is actively unwound from the roving drum under the driving of the pressing roller, and then enters the tension adjusting device, and is output by the tension adjusting device, and is output by the front roller of the roving frame, and the pressing output point of the fine-staple cotton roving at the front roller is located at the middle part of the long-staple cotton slub;

[0013] The seventh step: fine spinning, the long-fleece cotton / fine-fleece cotton core-spun roving prepared in the sixth step is drawn, twisted and wound by the drafting of the spinning frame to prepare long-fleece cotton / fine-fleece cotton mixed fine yarn with long-fleece cotton fiber outside and long-fleece cotton and fine-fleece cotton mixed fiber in the center; the long-fleece cotton / fine-fleece cotton core-spun roving is fed into the four-rods three-zone drafting structure of the spinning frame with fixed double short apron and elastic long-short apron respectively, under the synergistic action of the drafting roller and apron structure, the fine-fleece cotton roving in the center and the long-fleece cotton roving outside in the long-fleece cotton / fine-fleece cotton core-spun roving are stretched at the same time, at this time, the twist in the two rovings is removed during the stretching process, so that the long-fleece cotton and fine-fleece cotton fibers are mixed, and the long-fleece cotton fibers with long length and good consistency outside play a hindering role on the fine-fleece cotton fibers during the mixing process, so that the long-fleece cotton / fine-fleece cotton sliver obtained after drafting has long-fleece cotton fibers mainly outside and long-fleece cotton and fine-fleece cotton mixed fibers in the center, and finally long-fleece cotton / fine-fleece cotton mixed fine yarn with long-fleece cotton fibers outside and long-fleece cotton and fine-fleece cotton mixed fibers in the center is obtained under the action of the twisting twist.

[0014] The production method of low-cost pure cotton yarn as described above, preferably, the fine-fleece cotton carding step is: the selected fine-fleece cotton fibers are sequentially grabbed by the disc-type cotton grabber according to the mixing ratio, and the preliminary opening and mixing of the fine-fleece cotton fibers are realized during the grabbing process, the opened and mixed fine-fleece cotton fibers grabbed according to the mixing ratio are realized by the automatic cotton blender, and the impurities are separated and removed during the opening process, the various fine-fleece cotton fibers are fully mixed by the multi-bin cotton blender, and the opening and impurity removal of the fine-fleece cotton fibers are realized during the mixing process, the further opening, carding and impurity removal of the fine-fleece cotton fibers are realized by the porcupine opener, the uniform feeding of the opened cotton fibers is realized by the cotton feeder, the fine-fleece cotton flow delivered by the uniform feeding is formed into uniform fine-fleece cotton lap by the single beater lap former, and the fine-fleece cotton lap is subjected to the action of careful opening, carding, impurity removal and slivering by the carding machine to prepare fine-fleece cotton sliver.

[0015] The production method of low-cost pure cotton yarn as described above, preferably, the long-fleece cotton carding step is: the selected long-fleece cotton is grabbed by the reciprocating cotton grabber according to the mixing ratio, the grabbed long-fleece cotton fibers are air-flow driven and transported to condense by the condenser + double-axial-flow cotton opener, and the opening, impurity removal and mixing of the long-fleece cotton fibers are realized by the double-axial-flow cotton opener, the further opening, carding and impurity removal of the long-fleece cotton fibers are realized by the three-stick-roller cotton opener, the opened and uniformly arranged cotton layer is delivered to the carding machine by the cotton box, and the delivered long-fleece cotton layer is subjected to the action of more careful opening, carding, impurity removal and slivering in the carding machine to prepare long-fleece cotton sliver.

[0016] The low-cost pure cotton yarn production method as claimed in claim 1, wherein preferably, in the seventh step, a four-roller super large draft spinning frame is selected for the spinning frame, and a three-zone draft structure is adopted for the draft system of the spinning frame.

[0017] The low-cost pure cotton yarn production method as claimed in claim 1, wherein preferably, in the seventh step, the back draft zone between the back roller and the middle back roller is a draft finishing zone with a light roller rubber roller structure, the draft ratio of the back draft zone is set to be between 1.05 and 1.35, the long-fiber cotton roving located at the outside of the core roving of the long-fiber cotton / fine-fiber cotton core roving is stretched and thinned as a whole under the small draft of the back draft zone, the interaction force between the long-fiber cotton fibers is weakened in the stretching and thinning, and at the same time, the fine-fiber cotton roving located at the center is stretched and thinned as a whole under the small draft, the interaction force between the fine-fiber cotton fibers is weakened in the stretching and thinning, but since the draft ratio of the back draft zone is small, the long-fiber cotton fibers and the fine-fiber cotton fibers still have a clear inner-outer layered structure, thereby obtaining the first long-fiber cotton / fine-fiber cotton sliver with the long-fiber cotton fibers located at the outside and the fine-fiber cotton fibers located at the center.

[0018] The low-cost pure cotton yarn production method as claimed in claim 1, wherein preferably, the first long-fiber cotton / fine-fiber cotton sliver enters the middle draft zone between the middle back roller and the middle front roller, and a fixed apron control mechanism composed of a middle back lower short apron and a middle back upper short apron is extended into the middle draft zone through the fixed lower pin on the middle back roller and the fixed upper pin on the middle back upper rubber roller, the middle draft zone is a transition draft zone, and the draft ratio of the middle draft zone is set to be between 1.35 and 1.75, at this time, the long-fiber cotton sliver located at the outside of the first long-fiber cotton / fine-fiber cotton sliver is stretched and thinned under the synergistic action of the draft roller and the apron structure, and at the same time, the interaction force between the long-fiber cotton fibers is further weakened in the stretching and thinning, the fine-fiber cotton sliver located at the inside is stretched and thinned under the draft, and at the same time, the interaction force between the fine-fiber cotton fibers is further weakened in the stretching and thinning, and since the interaction force between the long-fiber cotton fibers at the outside and the fine-fiber cotton fibers at the inside is reduced, the fine-fiber cotton fibers at the inside gradually penetrate into the long-fiber cotton fibers under the control of the fixed apron structure in the state of a large number of fibers, thereby realizing the mutual mixing of the long-fiber cotton fibers and the fine-fiber cotton fibers, and the long-fiber cotton fibers located at the outside with a long length and good consistency hinder the fine-fiber cotton fibers, so that the mixing between the long-fiber cotton fibers and the fine-fiber cotton fibers only occurs at the middle part of the sliver, thereby obtaining the second long-fiber cotton / fine-fiber cotton sliver with the long-fiber cotton fibers located at the outside and the fine-fiber cotton fibers and a small amount of long-fiber cotton fibers located at the center.

[0019] The production method of low cost pure cotton yarn as described above, wherein preferably the second long-staple cotton / fine-staple cotton sliver enters into the front draft zone between the middle front roller and the front roller, and the middle front lower long apron and the middle front rubber roller on the middle front roller are provided by the fixed lower pin and the elastic tension frame, the middle front upper short apron is provided by the elastic upper pin on the middle front rubber roller, the middle front lower apron and the middle front upper apron press each other to form the elastic middle front apron control zone, the middle front apron control zone extends into the front draft zone, the front draft zone is the main draft zone, the draft ratio of the front draft zone is set between 15-70, at this time, the long-staple cotton sliver located outside in the second long-staple cotton / fine-staple cotton sliver is stretched and thinned under the action of large draft, and the interaction force between the long-staple cotton fibers is further weakened in the stretching and thinning, the fine-staple cotton and a small amount of long-staple cotton mixed sliver located inside is stretched and thinned under the action of draft, and the interaction force between the fibers is further weakened in the stretching and thinning, due to the reduction of the interaction force between the fibers, the fine-staple cotton fibers and the long-staple cotton fibers further penetrate and mix under the control of the elastic apron structure in the state of less fiber quantity, and the long-staple cotton fibers located outside with long length and good consistency hinder the fine-staple cotton fibers in the mixing process, so that the fine-staple cotton fibers are always away from the edge of the sliver, thereby obtaining the long-staple cotton / fine-staple cotton sliver with the long-staple cotton fibers located at the outermost edge and the fine-staple cotton fibers and the long-staple cotton fibers located in the middle.

[0020] The production method of low cost pure cotton yarn as described above, wherein preferably the long-staple cotton / fine-staple cotton sliver output by the draft system is twisted to obtain long-staple cotton / fine-staple cotton mixed yarn under the action of twisting degree, in the twisting process, due to the long length and good consistency of the length distribution of the long-staple cotton fibers located at the outermost edge in the sliver, the long-staple cotton fibers are directly bent under the action of twisting, and the long-staple cotton fibers are intertwined to form a net in the bending process to form long-staple cotton outer package yarn, the fine-staple cotton fibers and the long-staple cotton fibers located in the middle in the sliver are transferred to each other under the action of twisting degree, thereby obtaining long-staple cotton / fine-staple cotton core yarn with certain strength, thereby obtaining pure cotton yarn with long-staple cotton fibers outside and long-staple cotton and fine-staple cotton mixed fibers in the center.

[0021] The production method of low cost pure cotton yarn as described above, wherein preferably the sliver lap is obtained by using a lap machine, 16-24 long-staple cotton slivers obtained in the second step are guided by the sliver guide roller and the sliver guide compression roller, arranged in parallel and combined through the V-shaped platform and the rotation of 90°, the combined long-staple cotton sliver is guided by the sliver roller to enter the 3 / 3 draft device, the draft ratio of the draft device is between 1.1-1.4, the long-staple cotton layer is obtained after the combined long-staple cotton sliver is drafted, the long-staple cotton layer is compressed by the tight compression roller to prevent sticking, and then the long-staple cotton layer is driven by the cotton lap roller to form long-staple cotton lap.

[0022] The production method of low-cost pure cotton yarn as described above, wherein preferably, the drawing is performed by using a drawing frame, 6 long-fiber cotton rolls are respectively introduced into respective drawing devices, and the drawing ratio of the drawing device is between 5.2 and 7.5; the long-fiber cotton web after drawing of each long-fiber cotton roll is turned by 90 degrees through a smooth curved guide plate and then is superimposed and combined in 6 layers on a cotton conveying platform, and then is introduced into a compacting roller, and then is rolled into a long-fiber cotton fine combing lap by a lap forming roller.

[0023] Compared with the prior art, the application realizes the production of long-fiber cotton / short-fiber cotton core-spun roving with long-fiber cotton as the outer wrapping fiber and short-fiber cotton as the center by using the core-spun process in the roving process, realizes the production of long-fiber cotton / short-fiber cotton sliver with long-fiber cotton fibers mainly located at the outside and mixed fibers of long-fiber cotton and short-fiber cotton at the center by using the four-rooler three-zone drawing structure in the spinning process, and realizes the production of pure cotton yarn with long-fiber cotton fibers mainly at the outside and mixed fibers of long-fiber cotton and short-fiber cotton at the center by using the twisting process, thereby realizing the distribution control of the two fibers in the yarn body, realizing the production of high-quality pure cotton yarn in the case of reducing the amount of long-fiber cotton fibers, and realizing the low-cost production of pure cotton yarn with excellent appearance effect and yarn quality. DETAILED DESCRIPTION

[0024] The following examples described by reference are exemplary only and are presented for purposes of explanation and should not be interpreted to limit the application.

[0025] The application provides a production method of low-cost pure cotton yarn, and the method comprises the following steps:

[0026] First step: cotton distribution, the fine lint cotton is selected from Shandong Jinxiang cotton with an average length of 28.3 mm and an average micronaire value of 4.3, Hebei Dongguang cotton with an average length of 28.7 mm and an average micronaire value of 5.1, and Anhui Wuwei cotton with an average length of 27.2 mm and an average micronaire value of 4.9, and six packages of Shandong Jinxiang cotton, six packages of Hebei Dongguang cotton and one package of Anhui Wuwei cotton are arranged in each disc, and the arrangement sequence of the three cotton packages in each disc is as follows: two Shandong Jinxiang cotton packages and two Hebei Dongguang cotton packages are arranged at the center circle of the disc, and the two kinds of cotton packages are arranged at intervals, one Anhui Wuwei cotton package is arranged along the outer circle of the center of the disc, and four Shandong Jinxiang cotton packages and four Hebei Dongguang cotton packages are arranged at the outer circle of the disc, and the two kinds of cotton packages are arranged at intervals; the long lint cotton is selected from 100% Xinjiang long lint cotton fiber.

[0027] The second step is to card and prepare the fine lint cotton sliver by carding the selected fine lint cotton. In the fine lint cotton carding process, the selected fine lint cotton fibers are sequentially grabbed by the disc-type grabbing machine according to the mixing ratio, and the fine lint cotton fibers are preliminarily opened and mixed during the grabbing process. The fine lint cotton fibers grabbed according to the mixing ratio are opened and mixed by the automatic mixing machine, and the impurities are separated and removed during the opening process. The various fine lint cotton fibers are fully mixed by the multi-bin mixing machine, and the fine lint cotton fibers are opened and impurities are removed during the mixing process. The fine lint cotton fibers are further opened, carded, and impurities are removed by the porcupine carding machine. The opened cotton fibers are evenly fed to the cotton feeder by the cotton feeder. The fine lint cotton flow delivered by the single-beater lap former is formed into a uniform fine lint cotton lap. The carding process adopts the process principles of "reasonable cotton blending, multiple package use, frequent grabbing, sufficient mixing, short process, low speed, fine grabbing, sufficient mixing, gradual opening, reduced tumbling, multiple carding, more opening and less beating, thin feeding, light weight, large gauge, more mixing, early shedding, less breaking, no damage to fibers, carding instead of beating, less tumbling, anti-adhesion, gradual opening, less grabbing, sufficient mixing, low speed, and thin feeding". During the grabbing process, the fine grabbing principle is ensured by controlling the grabbing amount of each tooth of the disc grabbing machine to be small. In the automatic mixing process, the raw materials grabbed by the automatic grabbing machine are fed into the air flow generated by the condenser fan for mixing, high opening, and removal of part of the impurities. In the multi-bin mixing process, the raw materials are evenly blown into multiple cotton bins under the action of the air flow after being fed, forming raw material mixing. The fiber layers in each bin are transported through a 90° turn, and the excess fibers are thrown into the mixing chamber for further detailed mixing. In the porcupine carding process, the mechanical parts between the beater and the dust bar are used to complete the opening and impurity removal. In the vibrating feeding process, the fibers delivered by the condenser are further opened and mixed to be evenly fed into the lap former to form a lap. In the single-beater lap forming process, the mechanical parts between the beater and the dust bar are used to complete the opening and impurity removal, and a uniform fine lint cotton lap is formed. In the fine lint cotton carding process, the prepared fine lint cotton lap is subjected to detailed opening, carding, impurity removal, and sliver forming by the carding machine to prepare the fine lint cotton sliver.

[0028] The long lint cotton is prepared into a long lint cotton sliver by the carding process. In this process, the selected long lint cotton is grabbed by the reciprocating grabbing machine according to the mixing ratio. The grabbed long lint cotton fibers are transported and condensed by the airflow, and the long lint cotton fibers are opened, impurities are removed, and mixed by the double-shaft flow carding machine. The long lint cotton fibers are further opened, carded, and impurities are removed by the three-stick roller carding machine. The opened long lint cotton fibers are evenly arranged in the cotton box and then delivered to the carding machine. The delivered long lint cotton layer is subjected to more detailed opening, carding, impurity removal, and sliver forming in the carding machine to prepare the long lint cotton sliver.

[0029] The third step is to card the long-fleece cotton. The long-fleece cotton sliver prepared in the second step is subjected to a carding process to prepare long-fleece cotton sliver. The carding process includes carding preparation and carding. The carding preparation includes lap making and doubling. The lap making uses a lap machine. Sixteen to twenty long-fleece cotton slivers prepared in the second step are guided by a guide roller and a guide compression roller, are parallelly arranged and combined through a V-shaped platform which is turned by 90°, and are guided by a guide roller into a 3 / 3 draft device. The draft ratio of the draft device is between 1.1 and 1.4. The combined long-fleece cotton sliver is drafted to obtain a long-fleece cotton layer. The long-fleece cotton layer is compressed by a compression roller to prevent lap sticking. Then, the long-fleece cotton layer is made into long-fleece cotton lap by a lap roller. The doubling uses a doubling machine. Six long-fleece cotton laps are respectively introduced into respective draft devices. The draft ratio of the draft device is between 5.2 and 7.5, the long-fleece cotton net after the drafting of each long-fleece cotton roll is turned 90 degrees by a smooth curved guide plate and then is stacked and combined in 6 layers on a cotton conveying platform, and then enters a tight pressing roller and is rolled into a long-fleece cotton fine combing lap by a lap forming roller; the long-fleece cotton fine combing lap is combed into long-fleece cotton sliver by a combing machine, and the long-fleece cotton fiber is combed from front to back in the movement direction of the long-fleece cotton fiber in the combing machine; the combing machine includes a nipper feeding part, a cylinder carding part, a separating and combining part, and a sliver forming part; the nipper feeding part includes a cotton feeding roller and upper and lower nippers, and a tension roller is arranged at the rear of the nipper feeding part; the long-fleece cotton fine combing lap is pressed by the cotton feeding roller after passing through the tension roller; at this time, the tension of the long-fleece cotton fine combing lap during feeding is adjusted through the tension roller, so that the long-fleece cotton fine combing lap is uniformly fed into the nipper feeding part under the control of constant tension; the long-fleece cotton fine combing lap output by the cotton feeding roller is then gripped by the upper and lower nippers; the upper and lower nippers in the nipper feeding part swing back and forth periodically, and the long-fleece cotton fine combing lap is fed periodically through the back-and-forth swinging; the cylinder carding part includes a lower cylinder and an upper comb; the long-fleece cotton fine combing lap fed by the back-and-forth swinging of the nippers is gripped by the nippers effectively; the lower cylinder carding part carding the front end and the middle part of the long-fleece cotton fine combing lap fiber cluster extending out of the panel, so that short fibers and part of dust and impurities are removed in the carding process, and the fibers are straightened and parallelized; the upper comb carding the rear end of the fiber cluster, while preventing short fibers and dust and impurities clamped in the fiber cluster from re-entering the cotton net; the separating and combining part includes an upper separating roller and a lower separating roller; in each working cycle, the cotton net of the previous working cycle is first poured in, and the front end of the fiber cluster sent by the nippers is gripped in time and stacked on the poured cotton net to realize combination; because the speed of the separating nipper is greater than the speed of the fiber cluster fed by the comb, the fiber gripped by the separating nipper is separated from the fiber cluster fed by the comb, and the tail end of the fiber is carded by the comb; the sliver forming part includes a press roller and a lap former; the long-fleece cotton net output by the separating and combining part is gathered through a trumpet, so that the long-fleece cotton net is changed from a net structure to a sliver structure; the long-fleece cotton fiber recombined into a sliver structure is then pressed and fixed by the press roller and is continuously wound in a sliver can by the lap former, so that the long-fleece cotton sliver is obtained.

[0030] Fourth step: drawing, the fine lint cotton sliver prepared in the second step is drawn through three drawing processes to prepare fine lint cotton sliver, and the long lint cotton card sliver prepared in the third step is drawn through two drawing processes to prepare long lint cotton sliver; in the first drawing process, six fine lint cotton slivers are fed into the drawing system of the drawing frame, drawn and thinned, and then recombined to prepare the first fine lint cotton sliver, the draw ratio of the drawing system is between 6.05 and 6.5, the fibers in the fine lint cotton sliver are straightened and arranged through drawing, and the coarse and fine sections in the fine lint cotton sliver are randomly combined through recombination, so that the evenness of the sliver is improved, in the second drawing process, six first fine lint cotton slivers are fed into the drawing system of the drawing frame, drawn and thinned, and then recombined to prepare the second fine lint cotton sliver, the draw ratio of the drawing system is between 6.15 and 6.35, the fibers in the fine lint cotton sliver are straightened and arranged through drawing, and the coarse and fine sections in the fine lint cotton sliver are randomly combined through recombination, so that the evenness of the sliver is improved, in the third drawing process, six second fine lint cotton slivers are fed into the drawing system of the drawing frame, drawn and thinned, and then recombined to prepare the fine lint cotton sliver, the draw ratio of the drawing system is between 6.2 and 6.4, the fibers in the fine lint cotton sliver are straightened and arranged through drawing, and the coarse and fine sections in the fine lint cotton sliver are randomly combined through recombination, so that the evenness of the sliver is improved; in the first drawing process, six long lint cotton card slivers are fed into the drawing system of the drawing frame, drawn and thinned, and then recombined to prepare the long lint cotton semi-sliver, the draw ratio of the drawing system is between 6.45 and 6.55, the fibers in the long lint cotton card sliver are straightened and arranged through drawing, and the coarse and fine sections in the long lint cotton card sliver are randomly combined through recombination, so that the evenness of the sliver is improved, in the second drawing process, six long lint cotton semi-slivers are fed into the drawing system of the drawing frame, drawn and thinned, and then recombined to prepare the long lint cotton sliver, the draw ratio of the drawing system is between 6.15 and 6.35, the fibers in the long lint cotton semi-sliver are straightened and arranged through drawing, and the coarse and fine sections in the long lint cotton semi-sliver are randomly combined through recombination, so that the evenness of the sliver is improved.

[0031] Fifth step: fine cotton roving: the fine cotton sliver prepared in the fourth step is drawn and twisted by the drafting of the roving frame to prepare fine cotton roving. The roving frame not only continues to improve the straightness of the fiber, but also performs twisting and collection to create conditions for the large drafting of the spinning frame. The design of the roving process aims to improve the quality of the roving, achieve stable elongation, small weight difference, uniform sliver, tight structure, good forming, improve the quality of mechanical flat repair of the roving frame, ensure the normal engagement of the drafting gear, the bending of the roller and the eccentricity of the rubber roller, and the absence of oil, consistent opening of the condenser and appropriate installation position, flexible rotation of the rubber roller, correct starting position of the iron cannon, stable elongation rate, clean spindle shell, normal operation and no hanging flowers in the channel, thereby improving the roving sliver, reducing the weight irregularity and reducing the yarn defects; the space between the front roller and the second roller is the finishing area, the holding distance can be slightly greater than or equal to the quality length of the fiber, and is designed to be 35 mm; the space between the second roller and the third roller is the main drafting area, the holding distance is equal to the length of the rubber ring holder plus the length of the free area, and is designed to be 47 mm; the space between the third roller and the fourth roller is simple roller drafting, and the holding distance is designed to be 45 mm.

[0032] Sixth step: long cotton / fine cotton mixed roving: the long cotton sliver prepared in the fourth step and the fine cotton roving prepared in the fifth step are jointly prepared into long cotton / fine cotton core-spun roving by the roving frame. The long cotton sliver is fed into the drafting system of the roving frame by the rear roller of the roving frame, and the fed long cotton sliver is thinned by the drafting action of the drafting system to obtain long cotton sliver, and the obtained long cotton sliver is pressed and driven out by the front roller of the roving frame. A core-spun roving feeding device is arranged at the upper part of the drafting system of the roving frame, and the core-spun roving feeding device comprises a pressing roller and a tension adjusting device. The fine cotton roving wound on the roving drum is first pressed by the pressing roller and then unwound from the roving drum under the driving of the pressing roller. The unwound fine cotton roving then enters the tension adjusting device, and then is output by the tension adjusting device and pressed by the front roller of the roving frame, so that the tension of the fine cotton roving entering the front roller is adjusted by the tension adjusting device. The pressing output point of the fine cotton roving at the front roller is located at the middle part of the long cotton sliver, so that the fine cotton roving and the long cotton sliver are jointly pressed and output by the front roller of the roving frame. Under the action of the twisting degree, the long cotton sliver is twisted into long cotton roving, and the fine cotton roving is wrapped in the center during the twisting process, so that the long cotton / fine cotton core-spun roving is prepared, in which the long cotton roving is the outer roving and the fine cotton roving is the core yarn.

[0033] The seventh step is to spin the long-fleece cotton / fine-fleece cotton core-spun roving prepared in the sixth step into long-fleece cotton / fine-fleece cotton mixed yarn through drafting, twisting and winding on a spinning frame. The spinning frame is a four-roller three-zone super large drafting spinning frame. The drafting system of the spinning frame adopts a four-roller three-zone drafting structure. The fed long-fleece cotton / fine-fleece cotton core-spun roving first enters the back drafting zone between the back roller and the middle back roller. The back drafting zone is a drafting finishing zone with a light roller rubber-covered roller structure. The drafting multiple of the back drafting zone is set to be between 1.05 and 1.35. The long-fleece cotton roving outside is stretched and thinned as a whole under the small drafting action. The interaction force between the long-fleece cotton fibers is weakened in the stretching and thinning. Meanwhile, the fine-fleece cotton roving in the center is stretched and thinned as a whole under the small drafting action. The interaction force between the fine-fleece cotton fibers is weakened in the stretching and thinning. However, the drafting multiple of the back drafting zone is small, so the long-fleece cotton fibers and the fine-fleece cotton fibers still have a clear inner-outer layered structure at this time, so that the first long-fleece cotton / fine-fleece cotton sliver with the long-fleece cotton fibers outside and the fine-fleece cotton fibers in the center is obtained. Then the first long-fleece cotton / fine-fleece cotton sliver enters the middle drafting zone between the middle back roller and the middle front roller. A middle back lower short apron and a middle back rubber-covered roller are arranged on the middle back roller through fixed lower pins. A middle back upper short apron is arranged on the middle back rubber-covered roller through fixed upper pins. The middle back lower short apron and the middle back upper short apron constitute a fixed apron control mechanism which extends into the middle drafting zone. The middle drafting zone is a transition drafting zone. The drafting multiple of the middle drafting zone is set to be between 1.35 and 1.75. At this time, the long-fleece cotton sliver outside the first long-fleece cotton / fine-fleece cotton sliver is stretched and thinned under the synergistic action of the drafting roller and the apron structure. Meanwhile, the interaction force between the long-fleece cotton fibers is further weakened in the stretching and thinning. The fine-fleece cotton sliver inside is stretched and thinned under the drafting action. Meanwhile, the interaction force between the fine-fleece cotton fibers is further weakened in the stretching and thinning. Moreover, the interaction force between the long-fleece cotton outside and the fine-fleece cotton inside is reduced. In the state of a large number of fibers, the fine-fleece cotton fibers inside gradually penetrate into the long-fleece cotton fibers under the control of the fixed apron structure, so that the long-fleece cotton fibers and the fine-fleece cotton fibers are mixed with each other. In the mixing process, the long-fleece cotton fibers outside with long length and good consistency hinder the fine-fleece cotton fibers, so that the mixing between the long-fleece cotton fibers and the fine-fleece cotton fibers only occurs in the middle part of the sliver, so that the second long-fleece cotton / fine-fleece cotton sliver with the long-fleece cotton fibers outside and the fine-fleece cotton fibers and a small amount of long-fleece cotton fibers in the center is obtained. Then the second long-fleece cotton / fine-fleece cotton sliver enters the front drafting zone between the middle front roller and the front roller. A middle front lower apron is arranged on the middle front roller. A middle front lower long apron and a middle front rubber-covered roller are arranged on the middle front roller through fixed lower pins and elastic tension frames. A middle front upper short apron is arranged on the middle front rubber-covered roller through elastic upper pins. The middle front lower apron and the middle front upper apron press against each other to constitute an elastic middle front apron control zone which extends into the front drafting zone. The front drafting zone is a main drafting zone. The drafting multiple of the front drafting zone is set to be between 15 and 70.At this time, the long-staple cotton fiber in the outer part of the second long-staple cotton / fine-staple cotton sliver is greatly stretched and thinned under the action of large draft, and the interaction force between the long-staple cotton fibers is further weakened in the process of stretching and thinning. The fine-staple cotton and a small amount of long-staple cotton mixed sliver in the inner part is greatly stretched and thinned under the action of draft, and the interaction force between the fibers is further weakened in the process of stretching and thinning. Due to the reduction of the interaction force between the fibers, the fine-staple cotton fibers and the long-staple cotton fibers are further mixed under the control of the elastic apron structure in the state of a small number of fibers, and the long-staple cotton fibers with long length and good consistency in the outer part hinder the fine-staple cotton fibers in the mixing process, so that the fine-staple cotton fibers are always covered by the long-staple cotton fibers in the middle, thereby obtaining a long-staple cotton / fine-staple cotton sliver with long-staple cotton fibers in the outermost edge and fine-staple cotton fibers and long-staple cotton fibers in the middle. The long-staple cotton / fine-staple cotton sliver obtained by the drafting system is output and obtains a long-staple cotton / fine-staple cotton mixed yarn under the action of twisting. In the twisting process, the long-staple cotton fibers in the outermost edge of the sliver are directly bent under the action of twisting due to the long length and good length distribution consistency, and the long-staple cotton fibers are entangled to form a long-staple cotton outer package yarn in the bending process. The fine-staple cotton fibers and the long-staple cotton fibers in the middle of the sliver are transferred to each other under the action of twisting twist, thereby obtaining a long-staple cotton / fine-staple cotton core yarn with a certain strength, and thereby obtaining a pure cotton yarn with long-staple cotton fibers in the outer part and long-staple cotton and fine-staple cotton mixed fibers in the center. For example, the pure cotton woven yarn with a linear density of 60S, the corresponding process parameters are as follows: (1) raw material selection,

[0034] Long-staple cotton blending and performance index of each cotton bale

[0035]

[0036] Fine-staple cotton blending

[0037]

[0038] (2) Design of key process parameters

[0039] Fine-staple cotton opening and scutched cotton:

[0040] A002D disc type cotton picker

[0041] Process parameters Parameter design Trolley rotation speed (r / min) 1.8 Grabbing cotton beater speed (rpm) 740 Blade extension rib distance (mm) 2.75 Beater intermittent descent distance (mm / time) 3.25

[0042] FA017 type automatic cotton blender

[0043] Process parameters Parameter design Feeding roller speed (r / min) 2.59 Stripping beater speed (r / min) 429 Leveling beater speed (r / min) 272 Angle nail curtain speed (m / min) 80 Cotton conveying curtain degree (m / min) 2.17 Feeding curtain degree (m / min) 1.54 Angle nail curtain and stripping beater interval (mm) 1 Angle nail curtain and leveling beater interval (mm) 45

[0044] FA029 type multi-compartment cotton blender

[0045] Process parameters Parameter design Leveling roller speed (r / min) 726 Stripping roller speed (r / min) 543 Angle nail curtain speed (m / min) 110 Horizontal curtain speed (m / min) 0.7

[0046] FA106A type porcupine opener

[0047] Process parameters Parameter design Beater speed (r / min) 540 Feeding roller speed (r / min) 46 Beater and feeding roller interval (mm) 6.5 Beater and dust rod interval (mm) Inlet interval 12, outlet interval 16.5 Dust rod interval (mm) Inlet group 13, middle two groups 8, outlet group 5.5 Beater and stripping knife interval (mm) 1.6

[0048] FA161 type vibrating feeder

[0049] Process parameters Parameter design Angle nail curtain speed (m / min) 35 Flat curtain speed (m / min) 7.5 Leveling roller speed (r / min) 230 Stripping roller speed (r / min) 400 Feeding roller speed (r / min) 4.9 Stripping roller to inclined curtain interval (mm) 16

[0050] FA141A type single beater lap former

[0051]

[0052]

[0053] Opening and scutching integrated process

[0054]

[0055] Fine count cotton carding

[0056]

[0057] Long staple cotton combing preparation

[0058]

[0059] Long staple cotton combing

[0060]

[0061]

[0062] Fine count cotton drawing

[0063]

[0064] Fine count cotton roving

[0065]

[0066] Spinning

[0067]

[0068] (4) Quality testing

[0069] At the same time, the processing of pure cotton combed machine woven yarn of 60S long staple cotton was carried out with the selected long staple cotton, and the quality of the pure cotton yarn processed by the patent was compared, and the test results were as follows:

[0070] Yarn evenness test

[0071]

[0072] Yarn strength test

[0073]

[0074]

[0075] It is obvious from the test results that the pure cotton yarn processed from the fine and long staple cottons according to the present application is equivalent to the pure cotton combed yarn processed from the full long staple cotton in all indexes, especially in the strength CV and the yarn hairiness, because the fine and long staple cottons are used in core-in-sheath composite and the distribution of the two kinds of fibers in the yarn body is effectively controlled in the drafting process of the spinning process.

[0076] The structure, features and effects of the present application are described in detail according to the above shown embodiments, and the above description is only the preferred embodiments of the present application, but the present application is not limited to the shown embodiments, any change or modification made according to the concept of the present application, or the equivalent embodiments with equivalent changes within the scope of the description, should be within the protection scope of the present application.

Claims

1. A method for producing low cost pure cotton yarn, characterized in that, The method comprises the following steps: First step: cotton assorting, fine lint cotton is selected from Shandong Jinxiang cotton with average length of 28.3mm and average micronaire of 4.3, Hebei Dongguang cotton with average length of 28.7mm and average micronaire of 5.1, and Anhui Wuhai cotton with average length of 27.2mm and average micronaire of 4.9, and 6 packs of Shandong Jinxiang cotton, 6 packs of Hebei Dongguang cotton and 1 pack of Anhui Wuhai cotton are arranged in each disc, and the arrangement sequence of the three kinds of cotton in each disc is as follows: Two packs of Shandong Jinxiang cotton and two packs of Hebei Dongguang cotton are arranged on the outer circumferences of the discs, and the two kinds of cotton are arranged at intervals, one pack of Anhui Wuhai cotton is arranged along the outer circumference of the center of the disc, four packs of Shandong Jinxiang cotton and four packs of Hebei Dongguang cotton are arranged on the outer circumferences of the discs, and the two kinds of cotton are arranged at intervals, and long lint cotton is selected from 100% Xinjiang long lint cotton fiber; Second step: scutching, the selected fine lint cotton is scutched to obtain fine lint sliver, and the long lint cotton is scutched to obtain long lint sliver; Third step: long lint cotton carding, the long lint sliver obtained in the second step is sequentially wound and combined to obtain a carded sliver with excellent uniformity, and the carded sliver is carded to obtain long lint carded sliver; Fourth step: slivering, the fine lint sliver obtained in the second step is slivered in three passes to obtain fine lint slubbing, and the long lint carded sliver obtained in the third step is slivered in two passes to obtain long lint slubbing; Fifth step: fine lint cotton roving, the fine lint slubbing obtained in the fourth step is drafted and attenuated by the drafting system of the roving frame and twisted and wound to obtain fine lint roving; Sixth step: long lint cotton / fine lint cotton core-spun roving, the long lint slubbing obtained in the fourth step and the fine lint roving obtained in the fifth step are jointly roved by the roving frame to obtain long lint roving as the outer package roving and fine lint roving as the core yarn of the long lint / fine lint core-spun roving; a core-spun roving feeding device is arranged on the upper part of the drafting system of the roving frame, the core-spun roving feeding device comprises a pressing roller and a tension adjusting device, wherein the long lint slubbing is fed into the drafting system of the roving frame by the back roller of the roving frame, and the long lint slubbing is drafted by the drafting system to obtain long lint sliver, and the long lint sliver is pressed and output by the front roller, the fine lint roving on the roving drum is first pressed by the pressing roller, and then actively unwound from the roving drum under the driving of the pressing roller, and then enters the tension adjusting device, and then is output by the tension adjusting device and pressed and output by the front roller of the roving frame, and the pressing output point of the fine lint roving at the front roller is located at the middle part of the long lint sliver; The seventh step is to spin the long staple cotton / fine staple cotton core spun roving obtained in the sixth step through the drafting and thinning of the spinning frame, and to twist and wind to obtain long staple cotton / fine staple cotton mixed spun yarn with long staple cotton fibers on the outside and long staple cotton and fine staple cotton mixed fibers in the center; the long staple cotton / fine staple cotton core spun roving is fed into the four-rooler three-zone drafting structure of the spinning frame with fixed double short aprons and elastic long and short aprons, respectively, and under the synergistic action of the drafting roller and the apron structure, the fine staple cotton roving in the center and the long staple cotton roving on the outside of the long staple cotton / fine staple cotton core spun roving are stretched at the same time; at this time, the twist in the two rovings is removed during the stretching process, so that the long staple cotton and fine staple cotton fibers are mixed, and the long staple cotton fibers with long length and good consistency on the outside hinder the fine staple cotton fibers during the mixing process, so that the long staple cotton / fine staple cotton sliver obtained after drafting has long staple cotton fibers mainly on the outside and long staple cotton and fine staple cotton mixed fibers in the center, and finally long staple cotton / fine staple cotton mixed spun yarn with long staple cotton fibers on the outside and long staple cotton and fine staple cotton mixed fibers in the center is obtained under the action of twisting.

2. The method of producing low cost pure cotton yarn as claimed in claim 1 wherein, The fine staple cotton carding step is: the selected fine staple cotton fibers are sequentially grabbed by the disc type cotton grabber according to the mixing ratio, and the preliminary opening and mixing of the fine staple cotton fibers are realized during the grabbing process; the opened and mixed fine staple cotton fibers grabbed according to the mixing ratio are realized by the automatic cotton blender, and the impurities are separated and removed during the opening process; the full mixing of various fine staple cotton fibers is realized by the multi-bin cotton blender, and the opening and impurity removal of the fine staple cotton fibers are realized during the mixing process; the further opening, carding and impurity removal of the fine staple cotton fibers are realized by the porcupine opener; the uniform feeding of the opened cotton fibers is realized by the cotton feeder; the fine staple cotton flow delivered by the uniform feeding is formed into uniform fine staple cotton lap by the single beater lap former; and the fine staple cotton sliver is prepared after the fine staple cotton lap is subjected to the detailed opening, carding, impurity removal and slivering action of the carding machine.

3. The method of producing low cost pure cotton yarn as claimed in claim 1 wherein, The long staple cotton carding step is: the selected long staple cotton is grabbed by the reciprocating cotton grabber according to the mixing ratio; the grabbed long staple cotton fibers are air flow driven and delivered by the condenser + double shaft flow opener, and the opening, impurity removal and mixing of the long staple cotton fibers are realized by the double shaft flow opener; the further opening, carding and impurity removal of the long staple cotton fibers are realized by the three-stick roller opener; the opened and evenly arranged cotton layer is delivered to the carding machine after the cotton box; and the long staple cotton sliver is prepared after the delivered long staple cotton layer is subjected to more detailed opening, carding, impurity removal and slivering action in the carding machine.

4. The method of producing low cost pure cotton yarn as claimed in claim 1 wherein, In the seventh step, the four-rooler super large drafting spinning frame is selected, and the drafting system of the spinning frame adopts a three-zone drafting structure.

5. The method of producing low cost pure cotton yarn as claimed in claim 1 wherein, In the seventh step, the back drafting zone between the back roller and the middle back roller is a drafting finishing zone with a rubber-covered roller structure, the drafting multiple of the back drafting zone is set to be between 1.05-1.35, the long-staple cotton roving located outside of the core roving of the long-staple cotton / fine-staple cotton core roving is stretched and attenuated as a whole under the small drafting action of the back drafting zone, the interaction force between the long-staple cotton fibers is weakened in the stretching and attenuation, at the same time, the fine-staple cotton roving located in the center is stretched and attenuated as a whole under the small drafting action, the interaction force between the fine-staple cotton fibers is weakened in the stretching and attenuation, but since the drafting multiple of the back drafting zone is small, the long-staple cotton fibers and the fine-staple cotton fibers still have a clear inner and outer layered structure at this time, thereby obtaining the first long-staple cotton / fine-staple cotton sliver with the long-staple cotton fibers located outside and the fine-staple cotton fibers located in the center.

6. The method of producing low cost pure cotton yarn as claimed in claim 5 wherein, The first long-staple cotton / fine-staple cotton sliver enters into the middle drafting zone between the middle back roller and the middle front roller, and is additionally provided with a middle back lower short apron and a middle back rubber-covered roller on the middle back roller through the fixed lower pin, and a middle back upper short apron and a middle back rubber-covered roller on the middle back roller through the fixed upper pin, the fixed apron control mechanism composed of the middle back lower short apron and the middle back upper short apron extends into the middle drafting zone, the middle drafting zone is a transition drafting zone, the drafting multiple of the middle drafting zone is set to be between 1.35-1.75, at this time, the long-staple cotton sliver located outside of the first long-staple cotton / fine-staple cotton sliver is stretched and attenuated under the synergistic action of the drafting roller and the apron structure, at the same time, the interaction force between the long-staple cotton fibers is further weakened in the stretching and attenuation, the fine-staple cotton sliver located inside is stretched and attenuated under the drafting action, at the same time, the interaction force between the fine-staple cotton fibers is further weakened in the stretching and attenuation, and since the interaction force between the long-staple cotton fibers outside and the fine-staple cotton fibers inside is reduced, the fine-staple cotton fibers inside gradually penetrate into the long-staple cotton fibers under the control of the fixed apron structure in the state of a large number of fibers, thereby realizing the mutual mixing of the long-staple cotton fibers and the fine-staple cotton fibers, and the long-staple cotton fibers located outside with long length and good consistency hinder the fine-staple cotton fibers, so that the mixing between the long-staple cotton fibers and the fine-staple cotton fibers only occurs in the middle part of the sliver, thereby obtaining the second long-staple cotton / fine-staple cotton sliver with the long-staple cotton fibers located outside and the fine-staple cotton fibers and a small amount of long-staple cotton fibers located in the center.

7. The method of producing low cost pure cotton yarn as claimed in claim 6 wherein, The second long-staple cotton / fine cotton sliver enters into the front drafting zone between the middle front roller and the front roller, and the middle front lower long apron and the middle front rubber roller are arranged on the middle front roller by the fixed lower pin and the elastic tension frame, the middle front upper short apron is arranged on the middle front roller by the elastic upper pin, the middle front lower apron and the middle front upper apron press each other to form the elastic middle front apron control zone, the middle front apron control zone extends into the front drafting zone, the front drafting zone is the main drafting zone, the drafting ratio of the front drafting zone is set between 15-70, at this time, the long-staple cotton sliver located in the outside of the second long-staple cotton / fine cotton sliver is greatly stretched and thinned under the action of the large drafting, and the interaction force between the long-staple cotton fibers is further weakened in the stretching and thinning, the fine cotton and a small amount of long-staple cotton mixed sliver located in the inside is greatly stretched and thinned under the action of the drafting, and the interaction force between the fibers is further weakened in the stretching and thinning, due to the reduction of the interaction force between the fibers, the fine cotton fibers and the long-staple cotton fibers are further penetrated and mixed under the control of the elastic apron structure in the state of the small amount of fibers, and the long-staple cotton fibers located in the outside with the long length and good consistency hinder the fine cotton fibers in the mixing process, so that the fine cotton fibers are always not to the edge of the sliver, so that the long-staple cotton fiber is located in the outermost edge, and the fine cotton fiber and the long-staple cotton fiber are located in the middle of the long-staple cotton / fine cotton sliver.

8. The method of producing low cost pure cotton yarn as claimed in claim 7 wherein, The long-staple cotton / fine cotton sliver output by the drafting system is twisted to obtain the long-staple cotton / fine cotton mixed yarn under the action of the twisting twist, in the twisting process, due to the long length and good consistency of the length distribution of the long-staple cotton fiber located in the outermost edge of the sliver, so that the long-staple cotton fiber is directly bent under the action of the twisting, and the long-staple cotton fibers are mutually entangled to form the long-staple cotton outer package yarn in the bending process, the fine cotton fiber and the long-staple cotton fiber located in the middle of the sliver are mutually transferred under the action of the twisting twist, so that the long-staple cotton / fine cotton core yarn with certain strength is obtained, so that the pure cotton yarn with the long-staple cotton fiber in the outside and the long-staple cotton and fine cotton mixed fiber in the center is prepared.

9. The method of producing low cost pure cotton yarn as claimed in claim 1 wherein, The sliver lap is prepared by the sliver lap machine, 16-24 long-staple cotton slivers prepared in the second step are guided by the sliver guide roller and the sliver compression roller, are arranged in parallel and are combined after being turned over 90 degrees on the V-shaped platform, the combined long-staple cotton sliver is guided into the 3 / 3 drafting device by the sliver roller, the drafting ratio of the drafting device is between 1.1-1.4, the long-staple cotton layer is obtained after the combined long-staple cotton sliver is drafted, the long-staple cotton layer is compressed by the tight compression roller to prevent sticking, and then the long-staple cotton layer is driven by the cotton lap roller to prepare the long-staple cotton lap.

10. The method of producing low cost pure cotton yarn as claimed in claim 1 wherein, The lap is prepared by the lap machine, 6 long-staple cotton laps enter into the respective drafting device, and the drafting ratio of the drafting device is between 5.2-7.5, the long-staple cotton web after the drafting of each long-staple cotton lap is turned over 90 degrees by the smooth curved guide plate and is stacked and combined on the cotton conveying platform in 6 layers, and then enters into the tight compression roller, and is rolled into the long-staple cotton comber lap by the lap roller.

Images