CN116427075A

CN116427075A - High-yield production method of pure cotton combed yarn

Info

Publication number: CN116427075A
Application number: CN202310410885.1A
Authority: CN
Inventors: 周圆; 石宇航; 杨洁; 苏旭中
Original assignee: Yicheng Tianshu Textile Co ltd
Current assignee: Yicheng Tianshu Textile Co ltd
Priority date: 2023-04-17
Filing date: 2023-04-17
Publication date: 2023-07-14

Abstract

The invention provides a high-yield production method of pure cotton combed yarn, which is characterized in that cotton raw strips are pre-drawn by three paths to prepare cotton pre-drawn with greatly improved fiber straightening degree, a large gauge is adopted in a drafting zone, so that the fibers in the cotton raw strips are slipped under the large discrete distribution of speed change points in a drafting system, the fibers are effectively straightened in the mutual slipping process under the state of not being stretched, the fiber elasticity is kept, 24-30 cotton pre-drawn strips are fed together and then subjected to small drafting action within 1.1 times to obtain cotton combed rolls, the sliver evenness of the cotton combed rolls is effectively improved through large and cooperative action, short fiber removal is realized through post-drafting, drawing and pre-drafting, so that the problems of fiber straightening of the cotton raw strips, sliver drawing and short fiber removal through combing are realized, and the problem of tin Lin La broken fibers is effectively reduced, and the fiber preparation rate in the cotton combed yarn production is improved.

Description

High-yield production method of pure cotton combed yarn

Technical Field

The invention relates to the field of novel yarns, in particular to a high-yield production method of pure cotton combed yarns.

Background

With the development of social economy, the living standard of people is continuously improved, and as for the textile for clothes, fashion and functionality are increasingly focused, and unique styles and various functions such as antibacterial, antistatic and the like are pursued besides pursuing wearing comfort. To meet this consumer demand, the continued development of new yarns and fabrics is an important task in the textile industry. With the development of scientific technology, the textile market competition is more and more vigorous, and each manufacturer is continuously developed to a high-grade, good-technical content and high added value direction in order to pursue the maximization of profits.

In the processing of cotton fibers, in order to realize the production of textiles with high added values, the cotton fibers often need to be processed in a combing process, so that the processing of combed cotton slivers with more uniform fiber lengths is obtained, and the comprehensive quality of finished yarns is improved. And (3) straightening the hooked fibers in the fiber strips obtained by carding on one hand and removing the short fibers in the fiber strips on the other hand through combing. Before the combed yarn is processed, the processed strip cotton sliver needs to be subjected to a doubling and reeling process to be made into a rolled cotton roll obtained after a previous opening and picking process, so that preparation for combing is performed, namely, the preparation for combing is required before combing. At present, the commonly adopted combing preparation comprises a pre-drawing and a drawing and coiling process, so that the raw sliver containing more hooks does not have a sufficient fiber straightening effect before combing, and then the fibers in the sliver are easily broken due to the existence of the hooks in the combing cylinder combing process, and the broken fibers are removed as short fibers, so that the doffing rate is greatly increased, the fiber yield is greatly reduced, and the production cost is increased.

In view of the above, the invention provides a high-yield production method of pure cotton combed yarn, which is used for improving the yield of fibers in the production of pure cotton combed yarn and reducing the production cost.

Disclosure of Invention

The invention aims to provide a high-yield production method of pure cotton combed yarn, which is characterized in that cotton raw strips prepared by cotton carding are sequentially subjected to three pre-drawing steps, one strip drawing step and one rolling step and one combing step to prepare cotton combed strips, so that the processes of straightening fibers of the pre-drawn strips of the cotton raw strips, strip drawing and strip merging and short fiber removal by combing are realized, the original combing effect is effectively decomposed, the problem that the tin Lin La is broken in the original combing process is effectively reduced, the fiber yield in the pure cotton combed yarn production is improved, and the production cost is reduced.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a combed yarn of pure cotton is prepared from cotton fibers with length of 28.3mm at upper half, uniformity of 82.9, breaking strength of 28.09cN/dtex, average elongation of 6.84%, micronaire value of 4.66, maturity of 0.87, moisture regain of 7.48%, linter rate of 12.48% and impurity content of 2.79%, through removing impurities from cotton fibers, opening and carding to obtain strip raw cotton strips, beating and opening bulk cotton fibers in the opening and cleaning process of the opening and carding, separating and removing large impurities exposed in the opening process by air flow and centrifugal force, carding and dispersing the obtained cotton clumps in the carding process of the opening and carding to obtain raw cotton strips with greatly improved fiber separation, sequentially pre-drawing the raw cotton strips for fiber straightening, rolling and sliver merging, combing the raw cotton strips for short fiber removal, the method comprises the steps of preparing cotton combed sliver with greatly improved fiber straightening degree and length dispersion degree, combining the cotton combed sliver through two drawing steps, preparing cotton cooked sliver with further improved sliver evenness through twice combining action, further improving fiber straightening degree in a drawing process, drawing and twisting the cotton cooked sliver through a roving, so that the cotton fibers are mutually entangled to generate certain friction force in the twisting process, then preparing cotton roving with a certain internal friction force field, drawing and twisting the cotton roving through a spinning frame, and further realizing uniform large drawing effect of the cotton fibers in the cotton roving under the control of an internal friction force field, and then preparing pure cotton combed yarn with required linear density and larger strength, and the method specifically comprises the following steps:

The first step: a blowing-carding unit, wherein cotton fibers selected are sequentially subjected to reciprocating cotton grabbing, heavy object separation, free cotton opening, multi-bin cotton mixing, holding cotton opening, foreign fiber removal and dust removal to prepare flocculent cotton clusters, and the cotton clusters are continuously input into a carding machine after passing through a cotton feeding box to prepare strip-shaped raw cotton strips; in the reciprocating bale plucking process, selected cotton fibers are discharged along the length direction of a bale plucker, in the discharging process, the cotton fibers are divided into 10 rows according to the production place or the main body length, the 10 rows of cotton fibers are queued along the length direction of the bale plucker, 10 columns of cotton fibers are queued along the width direction of the bale plucker, 10 rows of cotton fibers are queued along the width direction of the bale plucker, in the discharging process, the 1 st row is discharged according to the sequence of the 1 st row, the 2 nd row and the 10 th row respectively, the 2 nd row is discharged according to the sequence of the 2 nd row, the 3 rd row, the 10 th row and the last 1 st row respectively, the 3 rd row is discharged according to the sequence of the 3 rd row, the 4 th row, the 10 th row and the last 1 st row and the 2 nd row respectively, the rows are sequentially and circularly staggered in turn according to the sequence, until 10 th horizontal row, each column is discharged according to the sequence of 10 th column, 9 th column and 1 st column respectively, the cotton fiber at the top is hit and opened by a cotton grabbing beater which circularly reciprocates along the length direction of the cotton grabbing machine, so that the hit and opened fiber is absorbed into a conveying pipe which is connected with the cotton grabbing beater in an intercommunication way under the action of negative pressure air flow in the cotton grabbing beater, the cotton fiber enters a heavy object separator after passing through the conveying pipe, in the heavy object separator, the cotton fiber flow is accelerated and conveyed forward by the air flow in a tapered pipeline, so that the cotton fiber flow is gradually thinned in the acceleration process, then large massive impurities in the cotton fiber flow are gradually and completely exposed, a 90-120 DEG turn is arranged in the pipeline, a impurity removing port is arranged at one outward side of the turn, the large blocky impurities in the cotton fiber flow are thrown out through the impurity removing opening at the turning part due to the action of large centrifugal force, and the cotton fiber with small mass turns smoothly under the supporting action of the external air flow flowing in through the impurity removing opening, so that the heavy objects in the cotton fiber flow are separated, the cotton fiber after the heavy objects are separated enters the free cotton opener after passing through the conveying pipe, the cotton fiber flow enters the free cotton opener, is driven by the air flow to rotate along the circumferential direction of the free cotton opening roller in a free state, and simultaneously moves forwards along the length direction of the free cotton opening roller, elastic angle nails are arranged on the free cotton opening roller according to a certain sequence, supporting rods are arranged at the lower part of the free cotton opening roller at equal radian intervals along the circumferential direction of the free cotton fiber flow, the rotating direction of the free cotton opening roller is opposite to that of the cotton fiber flow, so that the free cotton fiber flow is free to be beaten in the rotating process, in the free beating process, the elastic angle nails perform soft elastic beating on cotton fibers, so that the fibers in the cotton fiber flow are loosened under the beating action, the damage to the cotton fibers is reduced, when the cotton fiber flow rotates below the free beating hands, the impurities are positioned at the outer side of the cotton fiber flow under the action of gravity of the impurities, the cotton fibers in the cotton fiber flow at the inner side continuously rotate around the free beating roller under the holding action of the holding rod, and meanwhile, the impurities in the cotton fiber flow at the outer side generate the impact action with the holding rod in the moving process, so that the impurities fall along the gaps between the holding rods under the impact action, the impurity removal of the cotton fiber flow is realized, the cotton fibers after the free beating enter the multi-bin cotton mixer after passing through the conveying pipe, and the multi-bin cotton mixer, the cotton fiber flows sequentially fall into 6-8 high cotton bins, and the cotton fibers in each high cotton bin fall onto a transverse conveying curtain below after being stripped by a stripping beater, so that a cotton fiber layer is obtained after being mixed on the transverse conveying curtain, the cotton fiber layer is simultaneously grabbed along the thickness direction by a vertical cotton grabbing curtain, further mixing is realized in the grabbing process, the cotton fibers after multi-bin cotton mixing enter a holding opener after passing through a conveying pipe, the cotton fiber flows fall into an upper cotton box, an upper photoelectric tube and a lower photoelectric tube are arranged in the upper cotton box, the heights of the cotton fibers in the upper cotton box are dynamically changed between the upper photoelectric tube and the lower photoelectric tube, the cotton fibers at the bottom of the upper cotton box are held and output by a small-diameter holding roller pair after being gathered along the width direction by a large-diameter gathering roller pair, the other end of the holding and outputting cotton fiber is subjected to the beating and opening action of a holding and opening roller under the state that one end is held, steel angle nails are arranged on the holding and opening roller according to a certain sequence, the holding and opening roller is arranged in a trash collection box, an air inlet is formed on one entering side of cotton fiber flow of the trash collection box, a fiber outlet is formed on the other side of the trash collection box, holding sheets are arranged at the lower part of the holding and opening roller at intervals with unequal radians along the circumferential direction of the holding and opening roller, the holding sheets are of cuboid structures and extend to the fiber outlet all the time, the distance between two adjacent holding sheets from the lower part of the holding and opening roller to the fiber outlet is gradually increased, the distance between each holding sheet and the holding and opening roller is gradually increased, the included angle between each holding sheet and a horizontal straight line is gradually increased, in the beating and opening process, external air flow flows into the trash collection box through the air inlet, so that the output cotton fiber flow is tightly attached to the holding and opening roller, the steel angle nails on the holding and opening roller firstly impact and open cotton fibers in the cotton fiber flow, so that the cotton fibers in the cotton fiber flow are loosened, then the cotton fibers in the cotton fiber flow are carded and opened, so that the cotton fibers in the cotton fiber flow are separated, when the cotton fiber flow after holding and opening rotates below the holding and opening roller, the cotton fiber flow can continue to rotate upwards around the holding and opening roller under the holding action of the holding piece, at the moment, the impurities with larger mass are positioned at the outer side of the cotton fiber flow due to the action of self gravity, so that the impurities positioned at the outer side generate impact action with the holding piece, the impacted impurities fall along gaps between the holding pieces, the impurity removal action is realized, the cotton fiber flow which continues to rotate upwards generates impact with the holding piece at a larger speed under the driving of air flow, the impurity with larger mass relative to cotton fiber and located in the cotton fiber flow falls along the gap between the holding sheets under the impact action, and the cotton fiber with small mass returns to the collecting box under the holding action of the external air flow flowing in through the fiber outlet, so as to enter into the foreign fiber removing machine through the fiber outlet, the foreign fiber is removed, the cotton fiber flows through the roller to form a single fiber layer after being drawn, the single fiber layer is photographed through high-speed cameras which are arranged at equal intervals along the width direction of the fiber layer, the photographed picture is compared with the foreign fiber sample stored in the database, when the same characteristics exist between the photographed picture and one or more of the foreign fiber samples, the high-speed air gun below the high-speed camera for photographing the picture sends out the fiber flow at the corresponding position of the jet air flow, and then the foreign fiber in the cotton fiber flow is removed, the cotton fiber after foreign fiber removal enters a dust removing machine after passing through a conveying pipe, in the dust removing machine, the cotton fiber flow is driven by air flow in a tapered pipeline and then is accelerated to be conveyed forwards, so that the cotton fiber flow is gradually thinned in the acceleration process, the dust in the cotton fiber flow is gradually and completely exposed, the exposed dust is discharged through micropores, so that flocculent cotton clusters are prepared, the cotton clusters continuously enter a cotton feeding box after passing through the conveying pipe, the cotton clusters enter a cotton feeding box after being uniformly output after being processed by a high cotton box, the cotton clusters after being output continuously enter a carding machine, the cotton clusters are sequentially pressed and input, held and opened, transferred and carded, condensed into a net and gathered into strips to prepare strip cotton raw strips, the cotton clusters are pressed and fed between a lower supporting plate and an upper pressing roller in the pressing and inputting process, the other end of the fed cotton bale begins to receive the holding and opening action of a front rotating licker-in under the state that one end is pressed, steel carding needles are arranged on the circumference of the side surface of the licker-in a certain sequence, the steel carding needles perform the action of beating and carding on the fibers contacted with the cotton bale in the cotton bale during the holding and opening process, the held and opened cotton fibers are completely transferred to the licker-in and driven to rotate by the licker-in, a left impurity removing knife, a middle carding plate and a right dust removing knife are arranged below the licker-in, the knife tip of the left impurity removing knife is arranged along the length direction of the licker-in, the knife tip of the left impurity removing knife is arranged towards the licker-in direction, the middle carding plate is arranged along the circumference direction of the licker-in and is provided with impurity dropping slits at equal radian intervals, a carding needle cloth is arranged on one surface of the middle carding plate towards the licker-in the circumferential direction of the licker-in, the knife tip of the right dust removing knife is arranged towards the direction of the licker-in, the impurity in the cotton fiber which rotates to the lower part of the licker-in and the knife tip of the left impurity removing knife produce impact action, so that the impacted impurity falls down along the knife back of the left impurity removing knife, the cotton fiber is continuously driven to rotate by the licker-in, when the cotton fiber rotates to the middle carding plate, the cotton fiber is further opened under the synergistic action of the steel carding needle of the rotating licker-in and the carding card clothing of the static middle carding plate, so that the impurity exposed in the opening process falls down along the impurity falling seam under the action of centrifugal force, the cotton fiber is continuously driven to rotate by the licker-in under the holding of the middle carding plate, when the cotton fiber rotates to the right dust removing knife, the knife tip of the right dust removing knife cuts the airflow layer on the cotton fiber flow surface, the tiny dust floating in the airflow is separated from the cotton fiber in the cutting process, and simultaneously a holding action is produced on the cotton fiber, the cotton fiber is continuously driven by the licker-in the holding action, the cotton fibers driven by the licker-in are completely peeled by the cylinder to realize transfer, the cotton fibers transferred to the cylinder are driven by the cylinder to enter a carding area between the cylinder and the cover plate, the cotton fibers in the carding area are repeatedly transferred between the cylinder and the cover plate, so that the contact force between the fibers is gradually weakened in the transfer process, the cotton fibers are mutually separated until being in a single fiber shape, the cotton fibers in the carding area are taken out by the cylinder, one part of the taken-out cotton fibers are coagulated into a cotton fiber net after being peeled by the doffer, the other part of the taken-out cotton fibers are driven by the cylinder to continue to rotate, when the cotton fibers are rotated to the lower part of the cylinder, the supporting of the large leakage bottom arranged below the cylinder continues to rotate, and meanwhile, the shorter cotton fibers cannot fall under the supporting action of the large leakage bottom due to the large separation degree between the fibers, the short fibers are removed, the cotton fiber net condensed on the doffer is gathered through a horn mouth and then gathered into cotton fiber strips, the cotton fiber strips are pressed and finished to obtain cotton raw strips, and the cotton raw strips are continuously wound in a strip barrel after being driven by a strip winding mechanism;

And a second step of: cotton combing, namely sequentially carrying out fiber straightening on the cotton raw sliver obtained in the first step through three pre-drawing steps, carrying out sliver merging through one sliver drawing step and short fiber removing through one combing step, so as to obtain a cotton combed sliver with greatly improved fiber straightening degree and length dispersion degree; in the first pre-drawing process, 6 cotton raw strips are fed together, 6 cotton raw strips are fed into a drawing system at a certain first interval, after drawing, gathering is carried out to obtain a first pre-drawing, in the second pre-drawing process, 7 first pre-drawing is fed together, 7 first pre-drawing is fed into the drawing system at a certain second interval, the second interval is smaller than the first interval, gathering is carried out to obtain a second pre-drawing, in the third pre-drawing process, 8 second pre-drawing is fed into the drawing system at a certain third interval, the third interval is smaller than the second interval, gathering is carried out after drawing to obtain a third pre-drawing, the drawing system comprises a back drawing area and a front drawing area, the roller holding distance of the back drafting zone is between 2 times and 3 times of the main body length of the selected cotton fiber, the drafting multiple of the back drafting zone is between 1.2 and 2 times, the roller holding distance of the front drafting zone is between 1.5 times and 2 times of the main body length of the selected cotton fiber, the drafting multiple of the front drafting zone is between 3 and 6, the total drafting multiple of the drafting system is between 6.2 and 6.9, in the second pre-drawing, the roller holding distance of the back drafting zone is between 1.8 times and 2.8 times of the main body length of the selected cotton fiber, the drafting multiple of the back drafting zone is between 1.2 and 2, the roller holding distance of the front drafting zone is between 1.5 times and 1.8 times of the main body length of the selected cotton fiber, the drafting multiple of the front drafting zone is between 3 and 5.5, the total drafting multiple of the drafting system is between 7 and 7.2, in the third pre-drawing, the roller holding distance of the back drafting zone is between 1.6 times and 2.5 times of the main body length of the selected cotton fiber, the drafting multiple of the back drafting zone is between 1.2 and 1.9, the roller holding distance of the front drafting zone is between 1.4 times and 1.7 times of the main body length of the selected cotton fiber, the drafting multiple of the front drafting zone is between 3 and 5.5, and the total drafting multiple of the drafting system is between 7.8 and 8, in the back drafting zone, the fed 6 cotton raw strips, or the first pre-drawing strip or the second pre-drawing strip are converted into straightening fibers under the action of the larger roller holding distance and the smaller drafting multiple, then the whole drawing slip of step by step and small amplitude is carried out, then the cotton fiber enters the front drafting zone again, at the moment, under the action of the larger roller holding distance and the larger drafting multiple, the cotton fiber is randomly changed in a floating state without holding at both ends along the length direction of the front drafting zone, so that the mutual sliding occurs in the speed changing process, the fiber is in a complete floating state in the sliding process, so that the fiber is not in a stretching state in the sliding process, meanwhile, the random distribution of fiber speed changing points causes the head end and the tail end of the fiber to generate different speed changing in the speed changing process, when the front end of the fiber starts to change speed, the fiber main body and the rear end are still in a non-speed changing state, then when the front end of the fiber is provided with a hook, the hook part can generate relative motion relative to the fiber main body part due to the speed changing effect, then the front hook is straightened under the motion effect, when the front end of the fiber and the fiber main body are used for completing speed changing, the rear end of the fiber is still in a non-speed changing state, then when the rear end of the fiber is provided with the hook, the hook part can generate relative motion relative to the fiber main body part due to the speed changing effect, then the straightening of the rear hook is realized under the action of the movement;

Feeding 24-30 third pre-drawn strips in total into the strip drawing rolls, directly combining the fed first third pre-drawn strips to obtain a first initial roll with a certain width, directly combining the fed first third pre-drawn strips in total to obtain a second initial roll with a certain width, directly combining the fed third pre-drawn strips in total to obtain a third initial roll with a certain width, effectively improving the random mutual combination of the details, the thick knots and the normal parts of each third pre-drawn strip in the combining process, then respectively feeding the first initial roll, the second initial roll and the third initial roll into a drafting system to obtain a first combing small roll, a second combing small roll and a third combing small roll through small drafting within 1.1 times, in the drafting process, the fibers in each third pre-drawing are converted from an initial natural bending state to a natural straightening state, so that a certain gap is generated among the third pre-drawing in the width direction of each small combed roll, then the first small combed roll, the second small combed roll and the third small combed roll are respectively turned by 90 degrees and then are combined up and down to directly obtain a cotton combed roll, and in the up and down combining process, the cotton fibers in the first small combed roll, the second small combed roll and the third small combed roll are permeated with each other through the gap in each small combed roll, so that the uniformity of the cotton combed roll is further improved, and meanwhile, the mixing of the cotton fibers is realized;

The cotton comber comprises a back drafting device, an adsorption device, a sliver forming device and a front drafting device, wherein the back drafting device comprises a first back drafting roller pair and a second back drafting roller pair, the adsorption device is arranged at the front part of the back drafting device and comprises an adsorption roller, the adsorption roller is in a closed and hollow cylinder shape, outer adsorption holes are sequentially arranged along the side circumference of the adsorption roller, an adsorption arc is arranged in the adsorption roller and is in a hollow and closed sector structure, the cambered surface of the adsorption arc is tightly and smoothly contacted with the inner side surface of the upward side of the adsorption roller, an inner adsorption hole is sequentially arranged on the cambered surface of the adsorption arc, the adsorption arc is connected with a short negative pressure fan in an intercommunication way through an adsorption pipe, the adsorption pipe extends out from the round surface of the outward end of the adsorption roller, the adsorption tube is connected with the round surface of the adsorption roller through an adsorption connection bearing, so that an adsorption arc is always kept still in the rotation process of the adsorption roller, a front drafting device is arranged at the front part of the adsorption device, the adsorption device is arranged below a region between the rear drafting device and the front drafting device, the front drafting device sequentially comprises a first front drafting roller pair, a second front drafting roller pair and a third front drafting roller pair from back to front, the first front drafting roller pair is driven to rotate by a front drafting motor, the second front drafting roller pair is in transmission connection with the first front drafting roller pair through a first gear set for realizing acceleration transmission, the third front drafting roller pair is in transmission connection with the second front drafting roller pair through a second gear set for realizing acceleration transmission, and a strip forming device is arranged between the second front drafting roller pair and the third front drafting roller pair and comprises a horn mouth; the fed cotton combed roll enters a back drafting device, so that the cotton combed roll is subjected to large drafting action between a first back drafting roller pair and a second back drafting roller pair, then the cotton combed roll is thinned until a single fiber layer state is formed under the drafting action, so that a cotton fiber layer is obtained, the cotton fiber layer enters a front drafting device, at the moment, the cotton fiber layer is firstly held by the first front drafting roller pair, a front drafting motor drives the first front drafting roller pair to periodically move in a slow state and a fast state, when the first front drafting roller pair rotates slowly, the linear speed of the first front drafting roller pair is smaller than the linear speed of the second back drafting roller pair, so that the cotton fiber layer between the front drafting device and the back drafting device is in a loose sagging state, at the moment, under the action of negative pressure air flow in an absorbing roller rotating below, the cotton fiber in the cotton fiber layer is absorbed downwards, then, the cotton fiber with the rear end not held by the second rear drafting roller pair and the front end not held by the first front drafting roller pair is adsorbed onto the adsorption roller, so that the short fiber in the cotton fiber layer is removed, and the adjustment of the noil rate of combing is realized by setting the holding distance between the first front drafting roller pair and the second rear drafting roller pair, when the cotton fiber adsorbed onto the adsorption roller rotates to the lower part of the adsorption roller which is not contacted with an adsorption arc, the adsorption effect of the cotton fiber disappears, then the cotton fiber falls under the action of self gravity, the automatic cleaning of the adsorption roller is realized, when the first front drafting roller pair rotates fast, the linear speed of the first front drafting roller pair is greater than the linear speed of the second rear drafting roller pair, so that the cotton fiber layer between the front drafting device and the rear drafting device is in a tensioning state, the continuous conveying of the cotton fiber layer to the front drafting device is realized, the cotton fiber layer entering the front drafting device is firstly subjected to finishing drafting action between the first front drafting roller pair and the second front drafting roller pair, then subjected to gathering drafting action between the second front drafting roller pair and the third front drafting roller pair, and gathered into a sliver through a horn mouth in the gathering drafting process, so that the required cotton combed sliver is obtained;

And a third step of: processing spun yarn, namely sequentially drawing the cotton combed sliver obtained in the second step, roving and spinning to obtain the required pure cotton combed yarn; in the first drawing, 8 cotton combed strips are fed together, the fed 8 cotton combed strips are combined and then enter a drawing system, a semi-finished strip is obtained after drawing, in the second drawing, 6 semi-finished strips are fed together, the fed 6 semi-finished strips are combined and then enter the drawing system, and a cotton finished strip is obtained after drawing, so that the evenness of the obtained cotton finished strip is further improved through twice combining, and the fiber straightening degree is further improved in the drawing process; feeding the prepared 1 cotton sliver into a roving frame, drawing and twisting the fed 1 cotton sliver by the roving frame to prepare a cotton roving with certain strength, and continuously winding the prepared cotton roving on a roving bobbin, so that certain friction force is generated by mutual entanglement of cotton fibers in the twisting process, and the cotton roving has a certain internal friction force field; the prepared 1 piece of cotton roving is fed into a spinning frame, the fed 1 piece of cotton roving is subjected to drafting and twisting by the spinning frame to prepare pure cotton combed yarn with certain strength, and the prepared pure cotton combed yarn is continuously wound on a ring bobbin, so that cotton fibers in the cotton roving realize uniform large drafting under the control of an internal friction force field, and then the pure cotton combed yarn with required linear density and high strength is prepared.

The cotton raw sliver prepared by carding is subjected to three-channel pre-drawing to prepare cotton pre-drawing with fiber straightening degree greatly improved and sliver evenness deteriorated, a large gauge is adopted in a drawing zone in the pre-drawing process, so that the fiber in the cotton raw sliver is subjected to sliding under the large discrete distribution of speed change points in a drawing system, the fiber is effectively straightened in the mutual sliding process under the state of not being stretched, the elasticity of the fiber is effectively maintained, the cotton combed roll is obtained through the small drawing action within 1.1 times after 24-30 cotton pre-drawing are fed together, the sliver evenness of the cotton combed roll is effectively improved through large and cooperative actions, the short fiber removal action is realized through the processes of post-drawing, adsorption, sliver forming and front drawing, the pre-drawing of the cotton raw sliver is subjected to fiber straightening, sliver drawing and combing, the primary combing is carried out to remove the short fiber, the primary combing action is effectively decomposed, the primary combing effect is effectively reduced, and the fine combing cost is effectively reduced in the production process of the fine combing fiber is further reduced, and the production cost is effectively reduced Lin La.

The drawings in the specification:

Fig. 1 is a schematic view of the whole structure of the combing machine of the present invention.

Wherein: 1. the first back draft roller pair, 2, the second back draft roller pair, 3, the adsorption roller, 4, the outer adsorption hole, 5, the adsorption arc, 6, the adsorption tube, 7, the adsorption connecting bearing, 8, the first front draft roller pair, 9, the second front draft roller pair, 10, the third front draft roller pair, 11, the horn mouth, 12, the inner adsorption hole, 13, the first gear set, 14, the second gear set, 15, the front draft motor

The specific embodiment is as follows:

as shown in fig. 1, the combing machine comprises a back drafting device, an adsorption device, a sliver forming device and a front drafting device, wherein the back drafting device comprises a first back drafting roller pair 1 and a second back drafting roller pair 2, the adsorption device is arranged at the front part of the back drafting device and comprises an adsorption roller 3 which is in a closed and hollow cylinder shape, outer adsorption holes 4 are sequentially arranged along the side circumference of the adsorption roller, an adsorption arc 5 is arranged in the adsorption roller and is in a hollow and closed sector structure, the cambered surface of the adsorption arc is closely contacted with the inner side surface of the upward side of the adsorption roller in a smooth manner, an inner adsorption hole 12 is sequentially arranged on the cambered surface of the adsorption arc, the adsorption arc is connected with a short negative pressure fan in an intercommunication manner through an adsorption pipe 6, the adsorption pipe extends out from the round surface of the outward end of the adsorption roller, the adsorption tube is connected with the round surface of the adsorption roller through an adsorption connecting bearing 7, so that an adsorption arc is always kept still in the rotation process of the adsorption roller, a front draft device is arranged at the front part of the adsorption device, the adsorption device is arranged below a region between the rear draft device and the front draft device, the front draft device sequentially comprises a first front draft roller pair 8, a second front draft roller pair 9 and a third front draft roller pair 10 from back to front, the first front draft roller pair is driven to rotate by a front draft motor 15, the second front draft roller pair is in transmission connection with the first front draft roller pair through a first gear set 13 for realizing acceleration transmission, the third front draft roller pair is in transmission connection with the second front draft roller pair through a second gear set 14 for realizing acceleration transmission, a sliver forming device is arranged between the second front draft roller pair and the third front draft roller pair, the slitting device comprises a horn mouth 11.

A combed yarn of pure cotton is prepared from cotton fibers with length of 28.3mm at upper half, uniformity of 82.9, breaking strength of 28.09cN/dtex, average elongation of 6.84%, micronaire value of 4.66, maturity of 0.87, moisture regain of 7.48%, linter rate of 12.48% and impurity content of 2.79%, through removing impurities from cotton fibers, opening and carding to obtain strip raw cotton strips, beating and opening bulk cotton fibers in the opening and cleaning process of the opening and carding, separating and removing large impurities exposed in the opening process by air flow and centrifugal force, carding and dispersing the obtained cotton clumps in the carding process of the opening and carding to obtain raw cotton strips with greatly improved fiber separation, sequentially pre-drawing the raw cotton strips for fiber straightening, rolling and sliver merging, combing the raw cotton strips for short fiber removal, the method comprises the steps of preparing cotton combed sliver with greatly improved fiber straightening degree and length dispersion degree, combining the cotton combed sliver through two drawing steps, preparing cotton cooked sliver with further improved sliver evenness through twice combining action, further improving fiber straightening degree in a drawing process, drawing and twisting the cotton cooked sliver through a roving, so that the cotton fibers are mutually entangled to generate certain friction force in the twisting process, then preparing cotton roving with a certain internal friction force field, drawing and twisting the cotton roving through a spinning frame, and further realizing uniform large drawing effect of the cotton fibers in the cotton roving under the control of an internal friction force field, and then preparing pure cotton combed yarn with required linear density and larger strength, and the method specifically comprises the following steps:

Feeding the cotton combed roll into a combing machine, feeding the fed cotton combed roll into a rear drafting device, so that the cotton combed roll is subjected to large drafting action between a first rear drafting roller pair and a second rear drafting roller pair, thinning the cotton combed roll until the cotton combed roll is in a single fiber layer state under the drafting action, thereby obtaining a cotton fiber layer, then feeding the cotton fiber layer into a front drafting device, at the moment, firstly holding the cotton fiber layer by the first front drafting roller pair, driving the first front drafting roller pair to periodically move in a slow state and a fast state by a front drafting motor, when the first front drafting roller pair rotates at a slow speed, the linear speed of the first front drafting roller pair is smaller than the linear speed of the second rear drafting roller pair, so that the cotton fiber layer between the front drafting device and the rear drafting device is in a loose sagging state, at this time, under the action of negative pressure air flow in the adsorption roller rotating below, cotton fibers in the cotton fiber layer are downwards adsorbed, then the cotton fibers with the rear ends not held by the second back draft roller pair and the front ends not held by the first front draft roller pair are adsorbed on the adsorption roller, so that short fibers in the cotton fiber layer are removed, and the regulation of the noil combing rate is realized by setting the holding distance between the first front draft roller pair and the second back draft roller pair, when the cotton fibers adsorbed on the adsorption roller rotate to the lower part of the adsorption roller which is not contacted with an adsorption arc, the adsorption effect of the cotton fibers disappears, then the cotton fibers fall under the action of self gravity, then the automatic cleaning of the adsorption roller is realized, and when the first front draft roller pair rotates fast, the linear speed of the first front draft roller pair is larger than that of the second back draft roller pair, the cotton fiber layer between the front drafting device and the rear drafting device is in a tensioning state, so that continuous conveying of the cotton fiber layer to the front drafting device is realized, the cotton fiber layer entering the front drafting device is subjected to finishing drafting action between the first front drafting roller pair and the second front drafting roller pair, then is subjected to gathering drafting action between the second front drafting roller pair and the third front drafting roller pair, and is gathered into a sliver through a horn mouth in the gathering drafting process, so that the required cotton combed sliver is obtained;

Claims

1. The production method of the pure cotton combed yarn is processed by cotton fibers with the upper half part of 28.3mm, the uniformity of 82.9, the breaking strength of 28.09cN/dtex, the average elongation of 6.84%, the micronaire value of 4.66, the maturity of 0.87, the moisture regain of 7.48%, the linter rate of 12.48% and the impurity content of 2.79%, and is characterized in that: the method comprises the steps of sequentially processing selected cotton fibers through a blowing-carding machine, cotton combing and spun yarn processing to obtain required pure cotton combed yarns, removing impurities from the selected cotton fibers, opening and carding to obtain strip cotton raw strips in the blowing-carding machine, beating and loosening bulk cotton fibers in the blowing-carding machine, separating and removing large impurities exposed in the loosening process through the combined action of air flow and centrifugal force, and carding and dispersing the obtained cotton clusters in the carding process of the blowing-carding machine to obtain the cotton raw strips with greatly improved fiber separation degree; in cotton combing, cotton raw sliver is subjected to fiber straightening through three pre-drawing steps, sliver merging through one sliver merging roll and short fiber removing through one combing step, so that cotton combed sliver with greatly improved fiber straightening degree and length dispersion is prepared, a combing machine is adopted in combing, the combing machine comprises a rear drafting device, an adsorption device, a sliver forming device and a front drafting device, the rear drafting device comprises a first rear drafting roller pair and a second rear drafting roller pair, the adsorption device is arranged at the front part of the rear drafting device and comprises an adsorption roller, the adsorption roller is in a closed and hollow cylinder shape, outer adsorption holes are sequentially arranged along the side circumference of the adsorption roller, an adsorption arc is arranged in the adsorption roller, is in a hollow and closed sector structure, the cambered surface of the adsorption arc is tightly and smoothly contacted with the inner side surface of the upward side of the adsorption roller, an inner adsorption hole is arranged on the cambered surface of the adsorption arc in a certain sequence, the adsorption arc is communicated and connected with a short negative pressure fan through an adsorption pipe, the adsorption pipe extends out from the round surface at one end of the adsorption roller, the adsorption pipe is connected with the round surface of the adsorption roller through an adsorption connecting bearing, so that the adsorption arc always keeps still in the rotation process of the adsorption roller, a front drafting device is arranged at the front part of the adsorption device and below the area between the rear drafting device and the front drafting device, the front drafting device sequentially comprises a first front drafting roller pair, a second front drafting roller pair and a third front drafting roller pair from back to front, the first front drafting roller pair is driven to rotate by a front drafting motor, the second front drafting roller pair is in transmission connection with the first front drafting roller pair through a first gear set for realizing acceleration transmission, the third front drafting roller pair is in transmission connection with the second front drafting roller pair through a second gear set for realizing acceleration transmission, and a strip forming device is arranged between the second front drafting roller pair and the third front drafting roller pair and comprises a horn mouth; in the spinning process, the cotton combed sliver is combined through two drawing steps, so that the cotton combed sliver with further improved sliver uniformity is prepared through the twice combining action, the fiber straightening degree is further improved in the drawing process, the cotton combed sliver is drawn and twisted through one roving, so that the cotton fibers are mutually intertwined to generate certain friction force in the twisting process, the cotton roving with a certain internal friction force field is prepared, and the cotton roving is drawn and twisted through one spinning, so that the cotton fibers in the cotton roving realize uniform large drawing action under the control of the internal friction force field, and the pure cotton combed yarn with required linear density and high strength is prepared.

2. A method of producing pure cotton combed yarn according to claim 1, characterized by: in the blowing-carding machine, cotton fibers selected are sequentially subjected to reciprocating cotton grabbing, heavy object separation, free cotton opening, multi-bin cotton mixing, holding cotton opening, foreign fiber removal and dust removal to prepare flocculent cotton clusters, and the cotton clusters are continuously input into a carding machine after passing through a cotton feeding box to prepare strip-shaped raw cotton strips; in the reciprocating bale plucking process, selected cotton fibers are discharged along the length direction of a bale plucker, in the discharging process, the cotton fibers are divided into 10 rows according to the production place or the main body length, the 10 rows of cotton fibers are queued along the length direction of the bale plucker, 10 columns of cotton fibers are queued along the width direction of the bale plucker, 10 rows of cotton fibers are queued along the width direction of the bale plucker, in the discharging process, the 1 st row is discharged according to the sequence of the 1 st row, the 2 nd row and the 10 th row respectively, the 2 nd row is discharged according to the sequence of the 2 nd row, the 3 rd row, the 10 th row and the last 1 st row respectively, the 3 rd row is discharged according to the sequence of the 3 rd row, the 4 th row, the 10 th row and the last 1 st row and the 2 nd row respectively, the rows are sequentially and circularly staggered in turn according to the sequence, until 10 th horizontal row, each column is discharged according to the sequence of 10 th column, 9 th column and 1 st column respectively, the cotton fiber at the top is hit and opened by a cotton grabbing beater which circularly reciprocates along the length direction of the cotton grabbing machine, so that the hit and opened fiber is absorbed into a conveying pipe which is connected with the cotton grabbing beater in an intercommunication way under the action of negative pressure air flow in the cotton grabbing beater, the cotton fiber enters a heavy object separator after passing through the conveying pipe, in the heavy object separator, the cotton fiber flow is accelerated and conveyed forward by the air flow in a tapered pipeline, so that the cotton fiber flow is gradually thinned in the acceleration process, then large massive impurities in the cotton fiber flow are gradually and completely exposed, a 90-120 DEG turn is arranged in the pipeline, a impurity removing port is arranged at one outward side of the turn, the large blocky impurities in the cotton fiber flow are thrown out through the impurity removing opening at the turning part due to the action of large centrifugal force, and the cotton fiber with small mass turns smoothly under the supporting action of the external air flow flowing in through the impurity removing opening, so that the heavy objects in the cotton fiber flow are separated, the cotton fiber after the heavy objects are separated enters the free cotton opener after passing through the conveying pipe, the cotton fiber flow enters the free cotton opener, is driven by the air flow to rotate along the circumferential direction of the free cotton opening roller in a free state, and simultaneously moves forwards along the length direction of the free cotton opening roller, elastic angle nails are arranged on the free cotton opening roller according to a certain sequence, supporting rods are arranged at the lower part of the free cotton opening roller at equal radian intervals along the circumferential direction of the free cotton fiber flow, the rotating direction of the free cotton opening roller is opposite to that of the cotton fiber flow, so that the free cotton fiber flow is free to be beaten in the rotating process, in the free beating process, the elastic angle nails perform soft elastic beating on cotton fibers, so that the fibers in the cotton fiber flow are loosened under the beating action, the damage to the cotton fibers is reduced, when the cotton fiber flow rotates below the free beating hands, the impurities are positioned at the outer side of the cotton fiber flow under the action of gravity of the impurities, the cotton fibers in the cotton fiber flow at the inner side continuously rotate around the free beating roller under the holding action of the holding rod, and meanwhile, the impurities in the cotton fiber flow at the outer side generate the impact action with the holding rod in the moving process, so that the impurities fall along the gaps between the holding rods under the impact action, the impurity removal of the cotton fiber flow is realized, the cotton fibers after the free beating enter the multi-bin cotton mixer after passing through the conveying pipe, and the multi-bin cotton mixer, the cotton fiber flows sequentially fall into 6-8 high cotton bins, and the cotton fibers in each high cotton bin fall onto a transverse conveying curtain below after being stripped by a stripping beater, so that a cotton fiber layer is obtained after being mixed on the transverse conveying curtain, the cotton fiber layer is simultaneously grabbed along the thickness direction by a vertical cotton grabbing curtain, further mixing is realized in the grabbing process, the cotton fibers after multi-bin cotton mixing enter a holding opener after passing through a conveying pipe, the cotton fiber flows fall into an upper cotton box, an upper photoelectric tube and a lower photoelectric tube are arranged in the upper cotton box, the heights of the cotton fibers in the upper cotton box are dynamically changed between the upper photoelectric tube and the lower photoelectric tube, the cotton fibers at the bottom of the upper cotton box are held and output by a small-diameter holding roller pair after being gathered along the width direction by a large-diameter gathering roller pair, the other end of the holding and outputting cotton fiber is subjected to the beating and opening action of a holding and opening roller under the state that one end is held, steel angle nails are arranged on the holding and opening roller according to a certain sequence, the holding and opening roller is arranged in a trash collection box, an air inlet is formed on one entering side of cotton fiber flow of the trash collection box, a fiber outlet is formed on the other side of the trash collection box, holding sheets are arranged at the lower part of the holding and opening roller at intervals with unequal radians along the circumferential direction of the holding and opening roller, the holding sheets are of cuboid structures and extend to the fiber outlet all the time, the distance between two adjacent holding sheets from the lower part of the holding and opening roller to the fiber outlet is gradually increased, the distance between each holding sheet and the holding and opening roller is gradually increased, the included angle between each holding sheet and a horizontal straight line is gradually increased, in the beating and opening process, external air flow flows into the trash collection box through the air inlet, so that the output cotton fiber flow is tightly attached to the holding and opening roller, the steel angle nails on the holding and opening roller firstly impact and open cotton fibers in the cotton fiber flow, so that the cotton fibers in the cotton fiber flow are loosened, then the cotton fibers in the cotton fiber flow are carded and opened, so that the cotton fibers in the cotton fiber flow are separated, when the cotton fiber flow after holding and opening rotates below the holding and opening roller, the cotton fiber flow can continue to rotate upwards around the holding and opening roller under the holding action of the holding piece, at the moment, the impurities with larger mass are positioned at the outer side of the cotton fiber flow due to the action of self gravity, so that the impurities positioned at the outer side generate impact action with the holding piece, the impacted impurities fall along gaps between the holding pieces, the impurity removal action is realized, the cotton fiber flow which continues to rotate upwards generates impact with the holding piece at a larger speed under the driving of air flow, the impurity with larger mass relative to cotton fiber and located in the cotton fiber flow falls along the gap between the holding sheets under the impact action, and the cotton fiber with small mass returns to the collecting box under the holding action of the external air flow flowing in through the fiber outlet, so as to enter into the foreign fiber removing machine through the fiber outlet, the foreign fiber is removed, the cotton fiber flows through the roller to form a single fiber layer after being drawn, the single fiber layer is photographed through high-speed cameras which are arranged at equal intervals along the width direction of the fiber layer, the photographed picture is compared with the foreign fiber sample stored in the database, when the same characteristics exist between the photographed picture and one or more of the foreign fiber samples, the high-speed air gun below the high-speed camera for photographing the picture sends out the fiber flow at the corresponding position of the jet air flow, and then the foreign fiber in the cotton fiber flow is removed, the cotton fiber after foreign fiber removal enters a dust removing machine after passing through a conveying pipe, in the dust removing machine, the cotton fiber flow is driven by air flow in a tapered pipeline and then is accelerated to be conveyed forwards, so that the cotton fiber flow is gradually thinned in the acceleration process, the dust in the cotton fiber flow is gradually and completely exposed, the exposed dust is discharged through micropores, so that flocculent cotton clusters are prepared, the cotton clusters continuously enter a cotton feeding box after passing through the conveying pipe, the cotton clusters enter a cotton feeding box after being uniformly output after being processed by a high cotton box, the cotton clusters after being output continuously enter a carding machine, the cotton clusters are sequentially pressed and input, held and opened, transferred and carded, condensed into a net and gathered into strips to prepare strip cotton raw strips, the cotton clusters are pressed and fed between a lower supporting plate and an upper pressing roller in the pressing and inputting process, the other end of the fed cotton bale begins to receive the holding and opening action of a front rotating licker-in under the state that one end is pressed, steel carding needles are arranged on the circumference of the side surface of the licker-in a certain sequence, the steel carding needles perform the action of beating and carding on the fibers contacted with the cotton bale in the cotton bale during the holding and opening process, the held and opened cotton fibers are completely transferred to the licker-in and driven to rotate by the licker-in, a left impurity removing knife, a middle carding plate and a right dust removing knife are arranged below the licker-in, the knife tip of the left impurity removing knife is arranged along the length direction of the licker-in, the knife tip of the left impurity removing knife is arranged towards the licker-in direction, the middle carding plate is arranged along the circumference direction of the licker-in and is provided with impurity dropping slits at equal radian intervals, a carding needle cloth is arranged on one surface of the middle carding plate towards the licker-in the circumferential direction of the licker-in, the knife tip of the right dust removing knife is arranged towards the direction of the licker-in, the impurity in the cotton fiber which rotates to the lower part of the licker-in and the knife tip of the left impurity removing knife produce impact action, so that the impacted impurity falls down along the knife back of the left impurity removing knife, the cotton fiber is continuously driven to rotate by the licker-in, when the cotton fiber rotates to the middle carding plate, the cotton fiber is further opened under the synergistic action of the steel carding needle of the rotating licker-in and the carding card clothing of the static middle carding plate, so that the impurity exposed in the opening process falls down along the impurity falling seam under the action of centrifugal force, the cotton fiber is continuously driven to rotate by the licker-in under the holding of the middle carding plate, when the cotton fiber rotates to the right dust removing knife, the knife tip of the right dust removing knife cuts the airflow layer on the cotton fiber flow surface, the tiny dust floating in the airflow is separated from the cotton fiber in the cutting process, and simultaneously a holding action is produced on the cotton fiber, the cotton fiber is continuously driven by the licker-in the holding action, the cotton fibers driven by the licker-in are completely peeled by the cylinder to realize transfer, the cotton fibers transferred to the cylinder are driven by the cylinder to enter a carding area between the cylinder and the cover plate, the cotton fibers in the carding area are repeatedly transferred between the cylinder and the cover plate, so that the contact force between the fibers is gradually weakened in the transfer process, the cotton fibers are mutually separated until being in a single fiber shape, the cotton fibers in the carding area are taken out by the cylinder, one part of the taken-out cotton fibers are coagulated into a cotton fiber net after being peeled by the doffer, the other part of the taken-out cotton fibers are driven by the cylinder to continue to rotate, when the cotton fibers are rotated to the lower part of the cylinder, the supporting of the large leakage bottom arranged below the cylinder continues to rotate, and meanwhile, the shorter cotton fibers cannot fall under the supporting action of the large leakage bottom due to the large separation degree between the fibers, and then the short fiber removal effect is realized, the cotton fiber net condensed on the doffer is gathered into cotton fiber strips after being gathered through a horn mouth, the cotton fiber strips are pressed and finished to obtain cotton raw strips, and the cotton raw strips are continuously wound in a strip barrel after being driven by a strip winding mechanism.

3. A method of producing pure cotton combed yarn according to claim 1, characterized by: in cotton combing, the cotton raw sliver prepared by the blowing-carding is sequentially subjected to fiber straightening through three pre-drawing steps, sliver merging through one sliver drawing step and short fiber removing through one combing step, so that the cotton combing sliver with greatly improved fiber straightening degree and length dispersion degree is prepared; in the first pre-drawing process, 6 cotton raw strips are fed together, 6 cotton raw strips are fed into a drawing system at a certain first interval, after drawing, gathering is carried out to obtain a first pre-drawing, in the second pre-drawing process, 7 first pre-drawing is fed together, 7 first pre-drawing is fed into the drawing system at a certain second interval, the second interval is smaller than the first interval, gathering is carried out to obtain a second pre-drawing, in the third pre-drawing process, 8 second pre-drawing is fed into the drawing system at a certain third interval, the third interval is smaller than the second interval, gathering is carried out after drawing to obtain a third pre-drawing, the drawing system comprises a back drawing area and a front drawing area, the roller holding distance of the back drafting zone is between 2 times and 3 times of the main body length of the selected cotton fiber, the drafting multiple of the back drafting zone is between 1.2 and 2 times, the roller holding distance of the front drafting zone is between 1.5 times and 2 times of the main body length of the selected cotton fiber, the drafting multiple of the front drafting zone is between 3 and 6, the total drafting multiple of the drafting system is between 6.2 and 6.9, in the second pre-drawing, the roller holding distance of the back drafting zone is between 1.8 times and 2.8 times of the main body length of the selected cotton fiber, the drafting multiple of the back drafting zone is between 1.2 and 2, the roller holding distance of the front drafting zone is between 1.5 times and 1.8 times of the main body length of the selected cotton fiber, the drafting multiple of the front drafting zone is between 3 and 5.5, the total drafting multiple of the drafting system is between 7 and 7.2, in the third pre-drawing, the roller holding distance of the back drafting zone is between 1.6 times and 2.5 times of the main body length of the selected cotton fiber, the drafting multiple of the back drafting zone is between 1.2 and 1.9, the roller holding distance of the front drafting zone is between 1.4 times and 1.7 times of the main body length of the selected cotton fiber, the drafting multiple of the front drafting zone is between 3 and 5.5, and the total drafting multiple of the drafting system is between 7.8 and 8, in the back drafting zone, the fed 6 cotton raw strips, or the first pre-drawing strip or the second pre-drawing strip are converted into straightening fibers under the action of the larger roller holding distance and the smaller drafting multiple, then the whole drawing slip of step by step and small amplitude is carried out, then the cotton fiber enters the front drafting zone again, at the moment, under the action of the larger roller holding distance and the larger drafting multiple, the cotton fiber is randomly changed in a floating state without holding at both ends along the length direction of the front drafting zone, so that the mutual sliding occurs in the speed changing process, the fiber is in a complete floating state in the sliding process, so that the fiber is not in a stretching state in the sliding process, meanwhile, the random distribution of fiber speed changing points causes the head end and the tail end of the fiber to generate different speed changing in the speed changing process, when the front end of the fiber starts to change speed, the fiber main body and the rear end are still in a non-speed changing state, then when the front end of the fiber is provided with a hook, the hook part can generate relative motion relative to the fiber main body part due to the speed changing effect, then the front hook is straightened under the motion effect, when the front end of the fiber and the fiber main body are used for completing speed changing, the rear end of the fiber is still in a non-speed changing state, then when the rear end of the fiber is provided with the hook, the hook part can generate relative motion relative to the fiber main body part due to the speed changing effect, then the straightening of the rear hook is realized under the action of the movement; feeding 24-30 third pre-drawn strips in total into the strip drawing rolls, directly combining the fed first third pre-drawn strips to obtain a first initial roll with a certain width, directly combining the fed first third pre-drawn strips in total to obtain a second initial roll with a certain width, directly combining the fed third pre-drawn strips in total to obtain a third initial roll with a certain width, effectively improving the random mutual combination of the details, the thick knots and the normal parts of each third pre-drawn strip in the combining process, then respectively feeding the first initial roll, the second initial roll and the third initial roll into a drafting system to obtain a first combing small roll, a second combing small roll and a third combing small roll through small drafting within 1.1 times, in the drafting process, the fibers in each third pre-drawing are converted from an initial natural bending state to a natural straightening state, so that a certain gap is generated among the third pre-drawing in the width direction of each small combed roll, then the first small combed roll, the second small combed roll and the third small combed roll are respectively turned by 90 degrees and then are combined up and down to directly obtain a cotton combed roll, and in the up and down combining process, the cotton fibers in the first small combed roll, the second small combed roll and the third small combed roll are permeated with each other through the gap in each small combed roll, so that the uniformity of the cotton combed roll is further improved, and meanwhile, the mixing of the cotton fibers is realized; feeding the cotton combed roll into a combing machine, feeding the fed cotton combed roll into a rear drafting device, so that the cotton combed roll is subjected to large drafting action between a first rear drafting roller pair and a second rear drafting roller pair, thinning the cotton combed roll until the cotton combed roll is in a single fiber layer state under the drafting action, thereby obtaining a cotton fiber layer, then feeding the cotton fiber layer into a front drafting device, at the moment, firstly holding the cotton fiber layer by the first front drafting roller pair, driving the first front drafting roller pair to periodically move in a slow state and a fast state by a front drafting motor, when the first front drafting roller pair rotates at a slow speed, the linear speed of the first front drafting roller pair is smaller than the linear speed of the second rear drafting roller pair, so that the cotton fiber layer between the front drafting device and the rear drafting device is in a loose sagging state, at this time, under the action of negative pressure air flow in the adsorption roller rotating below, cotton fibers in the cotton fiber layer are downwards adsorbed, then the cotton fibers with the rear ends not held by the second back draft roller pair and the front ends not held by the first front draft roller pair are adsorbed on the adsorption roller, so that short fibers in the cotton fiber layer are removed, and the regulation of the noil combing rate is realized by setting the holding distance between the first front draft roller pair and the second back draft roller pair, when the cotton fibers adsorbed on the adsorption roller rotate to the lower part of the adsorption roller which is not contacted with an adsorption arc, the adsorption effect of the cotton fibers disappears, then the cotton fibers fall under the action of self gravity, then the automatic cleaning of the adsorption roller is realized, and when the first front draft roller pair rotates fast, the linear speed of the first front draft roller pair is larger than that of the second back draft roller pair, the cotton fiber layer between the front drafting device and the rear drafting device is in a tensioning state, continuous conveying of the cotton fiber layer to the front drafting device is achieved, the cotton fiber layer entering the front drafting device is subjected to finishing drafting action between the first front drafting roller pair and the second front drafting roller pair, then is subjected to gathering drafting action between the second front drafting roller pair and the third front drafting roller pair, and is gathered into a sliver through a horn mouth in the gathering drafting process, so that the required cotton combed sliver is obtained.

4. A method of producing pure cotton combed yarn according to claim 1, characterized by: in the spun yarn processing, the cotton combed sliver obtained in the second step is sequentially subjected to two drawing steps, one roving step and one spun yarn step to obtain the required pure cotton combed yarn; in the first drawing, 8 cotton combed strips are fed together, the fed 8 cotton combed strips are combined and then enter a drawing system, a semi-finished strip is obtained after drawing, in the second drawing, 6 semi-finished strips are fed together, the fed 6 semi-finished strips are combined and then enter the drawing system, and a cotton finished strip is obtained after drawing, so that the evenness of the obtained cotton finished strip is further improved through twice combining, and the fiber straightening degree is further improved in the drawing process; feeding the prepared 1 cotton sliver into a roving frame, drawing and twisting the fed 1 cotton sliver by the roving frame to prepare a cotton roving with certain strength, and continuously winding the prepared cotton roving on a roving bobbin, so that certain friction force is generated by mutual entanglement of cotton fibers in the twisting process, and the cotton roving has a certain internal friction force field; the prepared 1 piece of cotton roving is fed into a spinning frame, the fed 1 piece of cotton roving is subjected to drafting and twisting by the spinning frame to prepare pure cotton combed yarn with certain strength, and the prepared pure cotton combed yarn is continuously wound on a ring bobbin, so that cotton fibers in the cotton roving realize uniform large drafting under the control of an internal friction force field, and then the pure cotton combed yarn with required linear density and high strength is prepared.