A method for producing a regenerated polyester and cotton blended yarn

Abstract

The application discloses a production method of regenerated polyester and cotton blended yarn, which comprises the following steps: (1) cleaning and carding: separately preparing regenerated polyester sliver and cotton sliver through respective cleaning and carding combined procedures; (2) mixing: preparing regenerated polyester pre-drawing sliver through pre-drawing of the regenerated polyester sliver, preparing cotton pre-drawing sliver through pre-drawing of the cotton sliver, and then preparing regenerated polyester and cotton mature sliver through three-drawing of the regenerated polyester pre-drawing sliver and the cotton pre-drawing sliver; and (3) yarn forming: preparing regenerated polyester and cotton blended yarn through the procedures of roving, spinning and bobbin winding in sequence. The regenerated polyester pre-drawing sliver and the cotton pre-drawing sliver prepared independently are stretched respectively, pressed and combined, stretched together after being pressed, and stretched together after being combined horizontally and parallelly, so that the uniform mixing effect of the regenerated polyester fiber and the cotton fiber is realized, and then the production of the blended yarn with excellent comprehensive performance is realized.

Description

Technical Field

[0001] This invention relates to the field of novel yarns, and in particular to a method for producing recycled polyester and cotton blended yarn. Background Technology

[0002] my country is a major textile producer. With the rapid development of the textile industry, the application areas of textiles are constantly expanding, leading to a growing demand for various fibers. Among these, chemical fibers account for the largest share of both production and demand, representing approximately 84% of my country's total textile fiber processing volume in 2019. In recent years, my country's rapid economic development has brought resource shortages and environmental degradation into the way forward, becoming bottlenecks restricting economic growth. Polyester fiber ranks first in both production and usage among chemical fibers used in my country's textile industry. However, polyester fiber has poor biodegradability, resulting in a heavy burden on the environment from large quantities of waste polyester materials. Furthermore, due to resource scarcity, the development of the polyester industry, a downstream sector of the petrochemical industry, has also been constrained. Recycling waste yarn from spinning workshops, scraps from textile and garment enterprises, and some waste polyester materials to produce products with some use value could not only solve the problem of disposing of waste polyester materials, waste yarn, and scraps, reducing environmental harm, but also save energy and resources, reduce enterprise costs, and increase revenue while conserving resources.

[0003] To address the current bottlenecks in the textile industry, solutions must be found at the source. The emergence of recycled polyester has effectively resolved the contradiction between resource scarcity and increasingly prominent environmental pollution in my country. It is primarily made from waste polyester materials through specific physicochemical methods combined with spinning processes, and its properties are similar to traditional polyester fibers. However, compared to traditional polyester, recycled polyester has a slightly lower melting point, a significantly lower glass transition temperature, and considerably lower strength and tensile breaking properties, although it exhibits better alkali resistance. Given these differences between recycled and traditional polyester, new requirements have been placed on the production process of recycled polyester blended with cotton yarn. Summary of the Invention

[0004] The purpose of this invention is to provide a method for producing recycled polyester and cotton blended yarn to solve the problems in the prior art.

[0005] This invention provides a method for producing recycled polyester and cotton blended yarn, comprising the following steps:

[0006] (1) Cleaning and combing: Selected recycled polyester fibers and cotton fibers are processed into recycled polyester sliver and cotton sliver through their respective cleaning and combing processes;

[0007] For recycled polyester fiber: Selected recycled polyester fiber is sequentially processed through disc cotton grabbing, metal Mars dual-purpose detector, multi-compartment cotton blending, cotton opening, and carding to obtain recycled polyester sliver.

[0008] For cotton fibers: Selected mixed cotton fibers are sequentially passed through a disc cotton grabber, a metal-Mars dual-purpose detector, an airflow separator, a heavy object separator, a single-axis flow cotton opening, a multi-compartment cotton blending, a porcupine cotton opening, a cotton spinning foreign fiber removal machine, and a carding machine to obtain cotton sliver.

[0009] (2) Mixing: The recycled polyester sliver obtained in step (1) is pre-combined to obtain recycled polyester pre-combined sliver, and the cotton sliver is pre-combined to obtain cotton pre-combined sliver. The recycled polyester pre-combined sliver and the cotton pre-combined sliver are then combined through three combining processes to obtain recycled polyester cotton sliver.

[0010] Preparation of cotton pre-drawing: Eight cotton slivers are arranged in parallel along the thickness direction and fed together. The eight cotton slivers are then combined through a trumpet and enter the drafting system for drafting. The drafting ratio is set between 8.05 and 8.3. After drafting, the cotton pre-drawing is obtained by bundling with a bundler.

[0011] Preparation of recycled polyester pre-drawn sliver: Six recycled polyester slivers are arranged parallel to each other along the thickness direction and fed together. The six recycled polyester slivers are then combined through a bell mouth and enter the drafting system for drafting. The drafting ratio is set between 5.8 and 6.0. After drafting, the slivers are bundled by a bundler to obtain the corresponding recycled polyester pre-drawn sliver. The drafting system adopts a three-upper-three-lower pressure bar with guide rollers. The lower roller is made of special steel material and adopts advanced heat treatment technology. Both upper and lower roller bearings are high-precision needle roller bearings.

[0012] First drawing: An even number of recycled polyester pre-drawing slivers and an even number of cotton pre-drawing slivers are fed together, with the total number of recycled polyester pre-drawing slivers and cotton pre-drawing slivers fed being between 4 and 8. The fed recycled polyester pre-drawing slivers and cotton pre-drawing slivers are divided into two groups, and the number of recycled polyester pre-drawing slivers and cotton pre-drawing slivers in each group is the same. They are fed from back to front along the direction of fiber movement in the first drawing and fed into the feeding system, drafting system and winding system of the first drawing device to obtain a recycled polyester cotton blend sliver.

[0013] The first drawing assembly includes a feeding system, a drafting system, and a winding system. The feeding system includes an upper pressure roller pair and a lower pressure roller pair. An upper rear gathering bell mouth is located behind the upper pressure roller pair, and a lower rear gathering bell mouth is located behind the lower pressure roller pair. The upper and lower rear gathering bell mouths have identical structures, and their cross-sections are elliptical. Along the length direction of the upper and lower rear gathering bell mouths, the length of the major axis of the ellipse gradually decreases from back to front. As the heart rate gradually increases, the upper and lower pressure roller pairs have identical structures. Each pair includes an upper roller and a lower roller, with the lower roller driven by a corresponding transmission mechanism. Both the upper and lower rollers include an intermediate roller shaft, which is a solid cylindrical steel structure. A lower roller sleeve is fitted onto the intermediate roller shaft of the lower roller, and the lower roller sleeve is fixedly connected to the intermediate roller shaft. An upper roller sleeve is fitted onto the intermediate roller shaft of the upper roller, and the upper roller sleeve is connected to the intermediate roller shaft of the upper roller via a needle roller bearing. Both the upper and lower roller sleeves are made of hard rubber. The intermediate roller shaft of the lower roller of the lower pressure roller pair is driven to rotate by a corresponding transmission mechanism. The intermediate roller shafts of the lower rollers of the upper pressure roller pair are connected to each other via belt drives. The intermediate roller shafts of the upper rollers of the upper pressure roller pair and the intermediate roller shafts of the upper rollers of the lower pressure roller pair are connected by corresponding pressure rods. The upper end of the pressure rod is connected to the intermediate roller shaft of the upper roller of the upper pressure roller pair via an upper spring pressure assembly, and the lower end of the pressure rod is connected to the intermediate roller shaft of the upper roller of the lower pressure roller pair via a lower spring pressure assembly. The upper and lower spring pressure components have the same structure. When the pressure rod is pressed down with a certain pressure, the upper and lower spring pressure components are in a pressurized and locked state, thereby maintaining a certain pressure contact between the upper and lower rollers of the upper pressure roller pair and between the upper and lower rollers of the lower pressure roller pair. When the pressure rod is pulled up with a certain pressure, the upper and lower spring pressure components are in an extended and locked state, thereby maintaining a certain distance between the upper and lower rollers of the upper pressure roller pair and between the upper and lower rollers of the lower pressure roller pair.

[0014] The drafting system includes an upper drafting system and a lower drafting system. The upper drafting system is located in front of the upper pressure roller pair, and the lower drafting system is located in front of the lower pressure roller pair. The upper and lower drafting systems have the same structure. Both systems include a rear drafting roller pair, a middle drafting roller pair, and a front drafting roller pair. The rear drafting roller pair includes a rear lower roller and a rear upper roller. The middle drafting roller pair includes a middle lower roller and a middle upper roller. The front drafting roller pair includes a front lower roller and a front upper roller. The rear upper roller, middle upper roller, and front upper roller of the lower drafting system maintain a certain distance from the rear lower roller, middle lower roller, and front lower roller of the upper drafting system, respectively. The rear lower roller, middle lower roller, and front lower roller of the upper drafting system are respectively positioned relative to the rear lower roller, middle lower roller, and front lower roller of the lower drafting system, respectively. The front and lower rollers are connected by a belt drive. The rear upper roller, middle upper roller, and front upper roller of the upper drafting system are connected to the rear upper roller, middle upper roller, and front upper roller of the lower drafting system via pressure transmission connecting rods. Pressure rods are installed between the rear upper roller, middle upper roller, and front upper roller of the upper drafting system. When the pressure rods are on the platform, the rear upper roller, middle upper roller, and front upper roller of the upper drafting system maintain a certain distance from the rear lower roller, middle lower roller, and front lower roller of the upper drafting system, respectively. At this time, the rear upper roller, middle upper roller, and front upper roller of the upper drafting system, through corresponding pressure transmission connecting rods, maintain a certain distance from the rear upper roller, middle upper roller, and front lower roller of the lower drafting system, respectively. At a fixed interval, when the pressure rod presses down, the upper rear roller, middle upper roller, and front upper roller of the upper drafting system press tightly against the lower rear roller, middle lower roller, and front lower roller of the upper drafting system, respectively. At this time, the upper rear roller, middle upper roller, and front upper roller of the upper drafting system, through corresponding pressure transmission connecting rods, ensure that the lower rear roller, middle upper roller, and front upper roller of the lower drafting system press tightly against the lower rear roller, middle lower roller, and front lower roller of the lower drafting system, respectively. A pair of front pressure rollers is arranged in the middle in front of the upper and lower drafting systems. The pair of front pressure rollers includes an upper front roller and a lower front roller. The upper front roller and the lower front roller have the same structure and include an intermediate shaft. A pressing sleeve is fitted on the intermediate shaft, and the pressing sleeve is connected to the intermediate shaft through a bearing, allowing the pressing... The pressure sleeve rotates freely around the intermediate shaft. The intermediate shafts of the upper front roller and the lower front roller are connected by a knob-type pressing assembly. The knob-type pressing assembly includes an upper pressure spring and a lower pressure spring, which are connected by a pressing knob. When a certain force is applied and the pressing knob is rotated counterclockwise, the pressing knob is closed, thus putting the upper and lower pressure springs under elastic tension, thereby keeping the upper and lower front rollers pressed tightly together. When a certain force is applied and the pressing knob is rotated clockwise, the pressing knob is opened, thus putting the upper and lower pressure springs under natural extension, thereby maintaining a certain distance between the upper and lower front rollers. A front gathering trumpet is provided at the front of the front pressure roller pair, and the cross-section of the front gathering trumpet is an elliptical structure.Along the length of the front converging flare, from back to front, the length of the major axis of the ellipse in the cross-section gradually decreases, and the eccentricity gradually decreases, causing the output recycled polyester-cotton blend strips to gradually merge and recombine from a planar state back into a spatial ellipse;

[0015] The winding system includes a coiling disc, a base plate, and a sliver. The sliver is a hollow cylinder with an open top. The bottom of the sliver is closed and embedded in the base plate. A coiling spring is fixed on the base plate of the sliver. The lower end of the coiling spring is fixed to the circular surface at the bottom of the sliver. A release disc is provided at the upper end of the coiling spring. The release disc has a circular structure and the diameter of the coiling disc is smaller than the diameter of the sliver. The coiling disc is driven to rotate by a corresponding transmission mechanism. The base plate is driven to rotate by a corresponding transmission mechanism. The rotation direction of the coiling disc is the same as that of the base plate.

[0016] Second drawing: An even number of recycled polyester-cotton blend slivers are fed together, with the total number of recycled polyester-cotton blend slivers being between 6 and 8. In the second drawing, the fed recycled polyester-cotton blend slivers are divided into two groups, and the amount of recycled polyester in each group is the same. The fibers are fed from back to front into the feeding system, drafting system and winding system of the second drawing device along the direction of fiber movement in the second drawing to obtain a recycled polyester-cotton blend semi-cooked sliver.

[0017] The second drawing frame includes a feeding system, a drafting system, and a winding system. The feeding system includes an upper pressure roller pair and a lower pressure roller pair. The upper pressure roller pair and the lower pressure roller pair of the feeding system of the second drawing frame are exactly the same as those of the feeding system of the first drawing frame. An upper rear gathering bell mouth is provided on the rear side of the upper pressure roller pair, and a lower rear gathering bell mouth is provided on the rear side of the lower pressure roller pair. The upper rear gathering bell mouth and the lower rear gathering bell mouth of the second drawing frame are exactly the same as those of the first drawing frame.

[0018] The drafting system includes a rear drafting roller pair, a middle drafting roller pair, and a front drafting roller pair. The rear drafting roller pair includes a rear lower roller and a rear upper roller. The middle drafting roller pair includes a middle lower roller and a middle upper roller. The front drafting roller pair includes a front lower roller and a front upper roller. The rear upper roller, middle upper roller, and front upper roller are mounted on a pressure assembly, which is spring-loaded. When the pressure assembly presses down, it causes pressure to be applied between the rear lower roller and the rear upper roller, and between the middle lower roller and the middle upper roller. The front lower roller and the front upper roller are pressed into contact respectively. When the pressure assembly is raised, a certain distance is maintained between the rear lower roller and the rear upper roller, between the middle lower roller and the middle upper roller, and between the front lower roller and the front upper roller. A front gathering trumpet is provided at the front of the drafting system. The front gathering trumpet of the second drawing is exactly the same as that of the first drawing. The coiling system of the second drawing is exactly the same as that of the first drawing.

[0019] The third drawing process involves feeding 4-6 recycled polyester cotton mixed semi-finished slivers together, and feeding them from back to front into the feeding system, drafting system and winding system of the third drawing device along the direction of fiber movement in the third drawing process to obtain recycled polyester cotton finished sliver.

[0020] The third drawing assembly includes a feeding system, a drafting system, and a winding system. The feeding system includes a rear gathering bell, which is identical to the upper and lower rear gathering bells of the second drawing assembly. The drafting system of the third drawing assembly is identical to that of the second drawing assembly. A front gathering bell is located at the front of the drafting system, and this front gathering bell is identical to that of the second drawing assembly. The winding system of the third drawing assembly is identical to that of the second drawing assembly. The winding systems for drawing slivers are completely identical. During operation, the rear lower roller and rear upper roller, middle lower roller and middle upper roller, and front lower roller and front upper roller of the drafting system are all stopped and maintained at a certain distance. Four to six strands of recycled polyester-cotton blended semi-finished sliver are sequentially passed through the rear gathering bell mouth, between the rear lower roller and rear upper roller of the drafting system, between the middle lower roller and middle upper roller of the drafting system, between the front lower roller and front upper roller of the drafting system, and finally through the front gathering bell mouth, thus completing the initial winding process. Initially, the rear lower roller and rear upper roller, middle lower roller and middle upper roller, and front lower roller and front upper roller of the drafting system are all set to rotate and press against each other. During this process, 4-6 recycled polyester-cotton blend semi-finished slivers are arranged parallel to each other along the width direction of the blend and enter the rear gathering trumpet opening. As the diameter of the gathering trumpet opening decreases, the fed recycled polyester-cotton blend semi-finished slivers bulge vertically. Then, as the centrifugal force increases, the bulging part is pressed down again, causing... Four to six recycled polyester cotton blend semi-finished slivers are fed into the drafting system in an approximately planar and compact manner. The compact structure within the drafting system causes frictional forces between the fibers in the recycled polyester cotton blend semi-finished sliver, resulting in a recycled polyester cotton finished sliver with a more uniform linear density distribution. After passing through the front gathering trumpet, the recycled polyester cotton finished sliver gradually transforms from a planar state back into a spatial cylindrical structure before being output. The output recycled polyester cotton finished sliver is then wound into the sliver can by the winding disc.

[0021] (3) Yarn making: The recycled polyester cotton sliver obtained in step (2) is successively processed through roving, spinning and winding processes to obtain recycled polyester and cotton blended yarn.

[0022] The method for producing recycled polyester and cotton blended yarn as described above, wherein preferably, the raw materials used in the cleaning and combing process of the recycled polyester fiber in step (1) include 96.19% recycled polyester with a specification of 1.4D*38mm, 1.27% ECO / C wicking yarn, 1.27% ECO / C blended yarn, and 1.27% ECO / C roving ends.

[0023] The method for producing recycled polyester and cotton blended yarn as described above, wherein preferably, the raw materials used in the cotton fiber cleaning and carding process in step (1) include: 11.11% Grade 328, 9.1% moisture regain, and 4.69 micronaire value Aksu cotton; 11.11% Grade 328, 8% moisture regain, and 4.56 micronaire value Aksu cotton; 11.11% Grade 328, 8.8% moisture regain, and 4.72 micronaire value Urumqi cotton; and 11.11% Grade 328, 8.8% moisture regain, and 4.72 micronaire value Urumqi cotton. Aksu cotton with a value of 4.79, grade 328 with 11.11% moisture content, 8.3% moisture regain, and a micronaire value of 4.94; Aksu cotton with a value of 11.11%, grade 328 with 9.3% moisture regain, and a micronaire value of 4.85; Kuitun cotton with a value of 11.11%, grade 328 with 8.4% moisture regain, and a micronaire value of 3.91; Wanxing cotton with a value of 11.11%, grade 328 with 8.9% moisture regain, and a micronaire value of 4.71; and Aksu cotton with a value of 11.12%, grade 328 with 8.2% moisture regain, and a micronaire value of 4.68.

[0024] In the above-described method for producing recycled polyester and cotton blended yarn, preferably, the opening of the recycled polyester fiber in step (1) is performed by grip-beating opening, and the opening of the cotton fiber is performed by free-beating opening and grip-beating opening.

[0025] Compared with the prior art, the present invention achieves a uniform mixing effect of recycled polyester fiber and cotton fiber by separately drawing and pressing them together in the first drawing process, pressing them together in the second drawing process, and then drawing them together in the third drawing process, which is parallel to each other in the third drawing process. This results in the production of blended yarn with excellent comprehensive performance. Detailed Implementation

[0026] This invention provides a method for producing recycled polyester and cotton blended yarn, comprising the following steps:

[0027] (1) Cleaning and combing: Selected recycled polyester fibers and cotton fibers are processed into recycled polyester sliver and cotton sliver through their respective cleaning and combing processes.

[0028] For recycled polyester fiber: Selected recycled polyester fiber is sequentially processed through disc cotton grabbing, metal-Mars dual-mode detector, multi-compartment cotton blending, cotton opening, and carding to obtain recycled polyester sliver; In the embodiments provided in this application, the raw materials used in the cleaning and carding process of recycled polyester fiber include 96.19% recycled polyester with a specification of 1.4D*38mm, 1.27% ECO / C suction cotton, 1.27% ECO / C mixed sliver, and 1.27% ECO / C roving ends.

[0029] For cotton fibers: the selected blended cotton fibers are sequentially processed through a disc cotton picker, a metal-and-marble dual-function detector, an airflow separator, a heavy object separator, a single-axis flow opening process, a multi-compartment blending process, a porcupine opening process, a cotton spinning foreign fiber removal machine, and a carding machine to obtain cotton slivers; in the embodiments provided in this application, the raw materials used in the cotton fiber cleaning and carding process include 11.11% Grade 328, 9.1% moisture regain, and a micronaire value of 4.69 Aksu cotton; 11.11% Grade 328, 8% moisture regain, and a micronaire value of 4.56 Aksu cotton; and 11.11% Grade 328, 8.8% moisture regain, and a micronaire value of 4.72. Urumqi cotton, grade 328, 11.11% moisture content, 8.8% moisture regain, micronaire value 4.79; Aksu cotton, grade 328, 11.11% moisture content, 8.3% moisture regain, micronaire value 4.94; Aksu cotton, grade 328, 11.11% moisture content, 9.3% moisture regain, micronaire value 4.85; Kuitun cotton, grade 328, 11.11% moisture content, 8.4% moisture regain, micronaire value 3.91; Wanxing cotton, grade 328, 11.11% moisture content, 8.9% moisture regain, micronaire value 4.71; Aksu cotton, grade 328, 11.12% moisture content, 8.2% moisture regain, micronaire value 4.68.

[0030] During the cotton-grabbing process, to achieve the goal of gently and fully opening the raw cotton, the principle of frequent but light and precise cotton-grabbing is adopted. Regarding the distance the cotton-grabbing beater blades extend beyond the ribs, a shorter extension distance results in shallower insertion into the cotton layer, smaller cotton bundles grabbed, and better opening effect. To achieve full opening and precise cotton grabbing, this distance is kept relatively small. For the cotton-grabbing beater speed, a relatively high speed is used, resulting in more intense action of the blades on the cotton clumps, smaller and lighter cotton clumps grabbed, and better opening effect. The intermittent descent distance of the cotton-grabbing trolley is set relatively small while ensuring output. The intermittent descent distance of the beater is adjusted within the range of 1-6mm via a time relay on the control panel. The running speed of the cotton-grabbing trolley is set relatively high to increase the output of the cotton-grabbing machine and to grab more raw material components per unit time, which is beneficial for improving mixing but not for opening.

[0031] During the cotton opening process, gentle free-beating opening and vigorous gripping opening are used for cotton fibers, while vigorous gripping opening is used for recycled polyester fibers. In the free-beating opening, the roller speed is set to a slightly higher speed based on the raw cotton grade and impurity content to achieve thorough opening and impurity removal while preventing the formation of tufts due to roller fuzz. The distance between the roller and the dust bar is appropriately controlled to ensure effective opening and impurity removal while avoiding blockage of the beater passage. The distance between the dust bars is adjusted between 3-30°, corresponding to a distance between 6.262-10.292mm. Adjusting the dust bar angle allows for corresponding adjustments to the dust bar distance; a slightly larger distance during adjustment increases the cotton loss rate and enhances impurity removal.

[0032] During the opening and loosening process, the beater speed should be determined by considering factors such as the length, maturity, and impurity content of the processed fibers. For cotton fibers, a higher beater speed is recommended to facilitate opening, impurity removal, and the removal of short fibers. For recycled polyester fibers, a lower beater speed is recommended to reduce fiber damage and the destruction of large impurities during opening. The distance between the beater and the dust bar gradually increases from the inlet to the outlet. For cotton fibers, a smaller distance is recommended for strong opening and high fiber drop, while for recycled polyester fibers, a larger distance is recommended for slow opening and low fiber drop. The distance between the beater and the feed roller depends on the fiber length; 6-7mm is suitable for processing cotton and synthetic fibers shorter than 38mm. The distance between the dust bars gradually decreases from the inlet to the outlet, determined by the impurity content of the raw cotton and processing requirements. A larger distance at the inlet facilitates the first drop of large impurities, allowing for the replenishment of airflow.

[0033] During the cotton blending process, the raw materials are thoroughly mixed, while the process also includes opening, impurity removal, and uniform cotton feeding, providing a stable, uniform, and continuous cotton flow for the machinery in front. The selected cotton fibers or recycled polyester fibers are thoroughly mixed by sequentially using airflow mixing, layer mixing, and intensive mixing.

[0034] In the carding process, cotton fibers or recycled polyester fibers are finely combed to further remove highly adhesive impurities, short fibers, and neps, which greatly improves the separation between fibers. At the same time, the cylinder's re-carrying effect on the combed fibers achieves uniform mixing between individual fibers.

[0035] During the cotton fiber carding process, the cylinder is equipped with four fixed cover plates (front and rear) and one front and one rear web cleaner. The cover plates have a small heel-to-toe difference of 0.56mm and are reversed with the cylinder, allowing the rear cover plates, which are often clogged, to rotate out immediately, and the front and middle cover plates to be effectively carded, thereby improving carding quality and removing fine impurities. The web cleaner removes dust, lint, and short fibers, which helps improve the cleanliness of the web. Below the licker-in roller, there is a cotton drop adjustment plate, two dust removal knives, a pre-carding plate, a smooth triangular cover plate, and two suction ports, which expand the carding surface and enhance pre-carding, which helps to break down cotton bundles, reduce the load on the cylinder and the movable cover plates, and maximize the efficiency of fine carding. Below the cylinder, there are 12 smooth arc-shaped covers and two suction ports instead of the traditional large bottom vent. Suction pipes are installed on both sides of the dust collection box, controlled by PLC to suction once every 30 seconds, for a total of 10 suction points throughout the machine, so that the cotton drop from the machine body and the fly waste, dust, and short fibers on the machine can be removed in a timely manner. The corner area is designed to prevent cotton lint and dust from falling into the cotton web, thus improving the production environment. A self-regulating and leveling device with a mixing ring is installed. By detecting the linear density of the fed cotton clumps and the output sliver, the rotation speed of the feeding roller is adjusted in real time, significantly reducing the unevenness of the output sliver weight. A PLC-controlled multi-motor distributed drive system with variable frequency motor speed control and cotton suction system process parameter input on the panel, and an LCD display showing process and relevant quality data, enabling preliminary human-machine interaction. The cylinder is covered with AC2030×01540 metal card cloth, and the doffer with AD4032×02080 metal card cloth. The feeding roller is covered with a saw blade, providing multi-point cross-flexible gripping of the fed cotton clumps, which helps reduce fiber damage during high-speed licker-in. The three-roller stripping system supports the stripped cotton web and is equipped with a pneumatically operated arc-shaped cotton collector to ensure complete web transfer, bundling into slivers, and uninterrupted high-speed output.

[0036] For recycled polyester fibers, two sets of fixed carding plates are used, with dust removal knives and cotton support plates attached to the carding plates. The cotton support plates have four length specifications for easy replacement, allowing for adjustments to the lengths of the first and second waste disposal zones, thereby controlling cotton waste. The fixed carding plates increase the openness of the fiber raw material, improving the carding machine's waste removal and carding efficiency, reducing waste in the back zone, decreasing cotton consumption, preventing large cotton bundles from entering the cylinder-top carding zone, reducing the load on the cylinder needle surface, and extending the service life of the carding cloth. A three-roller stripping system is used, and the stripping rollers... The upper part is equipped with a right-angle steel wire elastic carding cloth, a high-speed rotating safety cleaning roller, and a photoelectric self-stop device to prevent damage to the doffer and cylinder carding cloth. The self-stop device consists of two parts: photoelectric self-stop and mechanical-electric self-stop. The doffer self-stop and the breakage self-stop are controlled by photoelectric technology, which is sensitive and reliable. The doffer self-stop is equipped with a doffer brake, which can stop the doffer quickly, thereby greatly reducing damage to the doffer and cylinder carding cloth. The DF-50 digital display controller is used for signal collection, data processing, keyboard input, and panel display.

[0037] (2) Mixing: The recycled polyester sliver obtained in step (1) is pre-combined to obtain recycled polyester pre-combined sliver, and the cotton sliver is pre-combined to obtain cotton pre-combined sliver. The recycled polyester pre-combined sliver and the cotton pre-combined sliver are then combined through three combining processes to obtain recycled polyester cotton sliver.

[0038] In the pre-drawing process, a drawing frame is used. For cotton slivers, eight cotton slivers are arranged in parallel along the thickness direction and fed together. The eight cotton slivers fed together are combined through the trumpet and then enter the drafting system for drafting. The drafting ratio is set between 8.05 and 8.3. After drafting, the slivers are bundled by the bundler to obtain the corresponding cotton pre-drawing sliver.

[0039] For recycled polyester sliver, in the pre-coupling process, six recycled polyester slivers are arranged in parallel along the thickness direction and fed together. The six recycled polyester slivers fed together are combined through a bell mouth and then enter the drafting system for drafting. The drafting ratio is set between 5.8 and 6.0. After drafting, the slivers are bundled by a bundler to obtain the corresponding recycled polyester pre-coupling sliver.

[0040] The drafting system employs a three-upper-three-lower pressure bar configuration with guide rollers. The sliver exit angle has been optimized for high-speed production. The sliver collector features a new design, reducing the impact of backflow airflow at the sliver exit interface and the bell-shaped connection on the fiber, achieving an ideal drafting state with fewer hooks and no wrinkles. The lower roller is made of special steel with optimized tooth design for better fiber gripping. Advanced heat treatment processes ensure excellent machining accuracy, surface finish, surface hardness, and internal toughness. Both upper and lower roller bearings are high-precision needle roller bearings, with rigorously calibrated load-bearing capacity and speed to meet high-speed requirements. The axial clearance of the upper roller can be adjusted at any time, and bearing lubrication and maintenance are convenient and reliable. The USTER SLIVERGUARD PRO / Second Generation Online Sliver Quality Management System is used to randomly statistically analyze the weight unevenness at 1m, 3m, and 10m lengths. It allows for automatic stop or alarm for exceeding limits, displaying the reason for the stop or alarm, thus facilitating quality control and analysis and reducing the workload of testing personnel.

[0041] By controlling the linear density of the recycled polyester pre-drawing sliver and cotton pre-drawing sliver obtained in the pre-drawing process, an even number of recycled polyester pre-drawing slivers and an even number of cotton pre-drawing slivers are fed together in the first drawing process. The specific number of recycled polyester pre-drawing slivers and cotton pre-drawing slivers fed is determined according to the blending ratio of the recycled polyester and cotton blended yarns spun, and the total number of recycled polyester pre-drawing slivers and cotton pre-drawing slivers fed is between 4 and 8. In the first drawing process, the required recycled polyester pre-drawing slivers and cotton pre-drawing slivers are divided into two groups, and the number of recycled polyester pre-drawing slivers and cotton pre-drawing slivers in each group is kept completely consistent. They are fed into the first drawing device from back to front along the direction of fiber movement in the first drawing process.

[0042] The first drawing assembly includes a feeding system, a drafting system, and a winding system. The feeding system comprises an upper pressure roller pair and a lower pressure roller pair. An upper rear gathering bell is located behind the upper pressure roller pair, and a lower rear gathering bell is located behind the lower pressure roller pair. The upper and lower rear gathering bells have identical structures, with elliptical cross-sections. Along the length of the ellipse from back to front, the length of the major axis gradually decreases while the eccentricity gradually increases, thus causing the fed recycled polyester pre-drawn sliver and cotton pre-drawn sliver to gradually combine. Flattened, the upper and lower pressure roller pairs have the same structure, each consisting of an upper roller and a lower roller. The lower roller is driven to rotate by a corresponding transmission mechanism, which in turn drives the lower roller, which is pressed tightly against the upper roller, to rotate synchronously in the opposite direction. Both the upper and lower rollers include an intermediate roller shaft, which is a solid cylindrical steel structure. A lower roller sleeve is fitted onto the intermediate roller shaft of the lower roller, and the lower roller sleeve is fixedly connected to the intermediate roller shaft of the lower roller. An upper roller sleeve is fitted onto the intermediate roller shaft of the upper roller, and the upper roller sleeve is connected to the intermediate roller shaft of the upper roller via a needle roller bearing. Both the lower and upper roller sleeves are made of hard rubber. The intermediate roller shaft of the lower roller of the lower pressure roller pair is driven to rotate by a corresponding transmission mechanism. The intermediate roller shafts of the lower rollers of the upper pressure roller pair are connected to each other via belt drives. The intermediate roller shafts of the upper rollers of the upper pressure roller pair are connected to each other via pressure rods. The upper end of the pressure rod is connected to the intermediate roller shaft of the upper roller of the upper pressure roller pair via an upper spring pressure assembly, and the lower end of the pressure rod is connected to the intermediate roller shaft of the upper roller of the lower pressure roller pair via a lower spring pressure assembly. The shafts are connected, and the upper and lower spring pressure components have the same structure. When a certain pressure is applied to the pressure rod, the upper and lower spring pressure components are in a pressurized and locked state, thereby maintaining a certain pressure contact between the upper and lower rollers of the upper pressure roller pair and between the upper and lower rollers of the lower pressure roller pair. When a certain pressure is applied to the pressure rod, the upper and lower spring pressure components are in an extended and locked state, thereby maintaining a certain distance between the upper and lower rollers of the upper pressure roller pair and between the upper and lower rollers of the lower pressure roller pair.

[0043] The drafting system includes an upper drafting system and a lower drafting system. The upper drafting system is located in front of the upper pressure roller pair, and the lower drafting system is located in front of the lower pressure roller pair. The upper and lower drafting systems have the same structure. Both systems include a rear drafting roller pair, a middle drafting roller pair, and a front drafting roller pair. The rear drafting roller pair includes a rear lower roller and a rear upper roller; the middle drafting roller pair includes a middle lower roller and a middle upper roller; and the front drafting roller pair includes a front lower roller and a front upper roller. The rear upper roller, middle upper roller, and front upper roller of the lower drafting system maintain a certain distance from the rear lower roller, middle lower roller, and front lower roller of the upper drafting system, respectively. The rear lower roller, middle lower roller, and front lower roller of the upper drafting system are respectively positioned relative to the rear lower roller, middle lower roller, and front lower roller of the lower drafting system, respectively. The lower rollers are connected by belt drive. The upper rear roller, middle roller, and front roller of the upper drafting system are connected to the lower rear roller, middle roller, and front roller of the lower drafting system via pressure transmission connecting rods. Pressure rods are installed between the upper rear roller, middle roller, and front roller of the upper drafting system. When the pressure rods are on the platform, the upper rear roller, middle roller, and front roller of the upper drafting system maintain a certain distance from the lower rear roller, middle roller, and front roller of the upper drafting system, respectively. At this time, the upper rear roller, middle roller, and front roller of the upper drafting system, through corresponding pressure transmission connecting rods, ensure that the lower rear roller, middle roller, and front roller of the lower drafting system maintain a certain distance from the lower rear roller, middle roller, and front roller of the lower drafting system, respectively. The spacing is such that when the pressure rod presses down, the upper rear roller, middle upper roller, and front upper roller of the upper drafting system press tightly against the lower rear roller, middle lower roller, and front lower roller of the upper drafting system, respectively. At this time, the upper rear roller, middle upper roller, and front upper roller of the upper drafting system, through corresponding pressure transmission connecting rods, ensure that the lower rear roller, middle upper roller, and front upper roller of the lower drafting system press tightly against the lower rear roller, middle lower roller, and front lower roller of the lower drafting system, respectively. A pair of front pressure rollers is set in the middle in front of the upper and lower drafting systems. The pair of front pressure rollers includes a front upper roller and a front lower roller. The front upper roller and the front lower roller have the same structure. The front upper roller and the front lower roller include an intermediate shaft. A pressing sleeve is sleeved on the intermediate shaft. The pressing sleeve is connected to the intermediate shaft through a bearing, thereby making the pressing... The pressure sleeve rotates freely around the intermediate shaft. The intermediate shafts of the upper front roller and the lower front roller are connected by a knob-type pressing assembly. The knob-type pressing assembly includes an upper pressure spring and a lower pressure spring, which are connected by a pressing knob. When a certain force is applied and the pressing knob is rotated counterclockwise, the pressing knob is closed, thus putting the upper and lower pressure springs under elastic tension, thereby keeping the upper and lower front rollers pressed tightly together. When a certain force is applied and the pressing knob is rotated clockwise, the pressing knob is opened, thus putting the upper and lower pressure springs under natural extension, thereby maintaining a certain distance between the upper and lower front rollers. A front gathering trumpet is provided at the front of the front pressure roller pair, and the cross-section of the front gathering trumpet is an elliptical structure.Along the length of the front converging flare, from back to front, the length of the major axis of the ellipse in the cross-section gradually decreases, and the eccentricity gradually decreases, causing the output recycled polyester-cotton blend strips to gradually merge and recombine from a planar state back into a spatial ellipse.

[0044] The winding system includes a coiling disc, a base plate, and a sliver tube. The sliver tube is a hollow cylinder with an open top. The bottom end of the sliver tube is closed and embedded in the base plate. A coiling spring is fixed on the base plate of the sliver tube, and the lower end of the coiling spring is fixed to the circular surface of the bottom end of the sliver tube. A release disc is provided at the upper end of the coiling spring. The release disc has a circular structure, and the diameter of the coiling disc is smaller than the diameter of the sliver tube. The coiling disc is driven to rotate by a corresponding transmission mechanism, and the base plate is driven to rotate by a corresponding transmission mechanism. The rotation direction of the coiling disc is the same as the rotation direction of the base plate.

[0045] During use, the upper and lower rollers of the upper pressure roller pair, the upper and lower rollers of the lower pressure roller pair, the rear lower roller and rear upper rubber roller of the upper drafting system, the middle lower roller and middle upper rubber roller of the upper drafting system, the front lower roller and front upper rubber roller of the upper drafting system, the rear lower roller and rear upper rubber roller of the lower drafting system, the middle lower roller and middle upper rubber roller of the lower drafting system, the front lower roller and front upper rubber roller of the lower drafting system, and the front upper roller and front lower roller of the front pressure roller pair are all stopped and maintained at a certain distance. The first set of recycled polyester pre-drawing sliver and cotton pre-drawing sliver are passed sequentially through the upper and rear gathering bell mouth, between the upper and lower rollers of the upper pressure roller pair, between the rear lower roller and rear upper rubber roller of the upper drafting system, between the middle lower roller and middle upper rubber roller of the upper drafting system, and between the front lower roller of the upper drafting system. The second set of recycled polyester pre-drawing sliver and cotton pre-drawing sliver are passed sequentially through the lower rear gathering bell mouth, between the upper and lower rollers of the lower pressure roller pair, between the rear lower roller and rear upper roller of the lower drafting system, between the middle lower roller and middle upper roller of the lower drafting system, between the front lower roller and front upper roller of the lower drafting system, between the front upper roller and front lower roller of the front pressure roller pair, and the front gathering bell mouth, thus completing the initial setup. Then, the upper and lower rollers of the upper pressure roller pair, the upper and lower rollers of the lower pressure roller pair, the rear lower roller and rear upper roller of the upper drafting system, the middle lower roller and middle upper roller of the upper drafting system, the front lower roller and front upper roller of the upper drafting system, and the rear lower roller of the lower drafting system are passed through. The upper and lower rollers of the drawing system, the middle and upper rollers of the lower drawing system, the front lower rollers and front upper rollers of the lower drawing system, and the front upper and lower rollers of the front pressure roller pair are all configured to maintain rotation and press against each other. During this process, the first group of recycled polyester pre-drawing slivers and cotton pre-drawing slivers, and the second group of recycled polyester pre-drawing slivers and cotton pre-drawing slivers are fed into the upper and lower drawing systems through the upper and lower rear gathering bell mouths, respectively. This causes the first and second groups of recycled polyester pre-drawing slivers and cotton pre-drawing slivers to gradually transform from a cylindrical shape to a horizontal planar shape, and to gradually merge during the transformation. After merging, the first group of recycled polyester pre-drawing slivers and cotton pre-drawing slivers are further transformed into a planar shape by being pressed by the upper and lower rollers of the upper pressure roller pair. The first recycled polyester-cotton blend sliver is fed into the upper drafting system. After drafting in the upper drafting system, a first recycled polyester-cotton blend sliver with reduced linear density is obtained. Due to the reduced linear density, the fibers in the first recycled polyester-cotton blend sliver maintain a certain gap. The second recycled polyester pre-drawn sliver and cotton pre-drawn sliver are then pressed by the upper and lower rollers of the upper pressure roller pair, further transforming them into a planar shape before being fed into the upper drafting system. After drafting in the lower drafting system, a second recycled polyester-cotton blend sliver with reduced linear density is obtained. Due to the reduced linear density, the fibers in the second recycled polyester-cotton blend sliver maintain a certain gap. The first and second recycled polyester-cotton blend slivers are then pressed together between the upper and lower rollers of the front pressure roller pair.During the pressing process, the fibers in the first and second recycled polyester-cotton blend strips interlock, resulting in a random mixing of recycled polyester and cotton fibers. This produces a planar recycled polyester-cotton blend strip. After passing through the front gathering flare, the strip gradually transforms from a planar state back into a spatial cylindrical structure before being output. The output strip is then wound around a sliver tube by a coiling disc. During this winding process, the coiling disc rotates the strip, and simultaneously, the base plate rotates the sliver tube, allowing the recycled polyester-cotton blend strip to overlap and wrap around the circumference of the sliver tube. The strip continuously winds around a release disc on the sliver tube, which gradually presses down on the coiling spring, thus completing the winding of the recycled polyester-cotton blend strip within the sliver tube.

[0046] In the second drawing process, an even number of recycled polyester-cotton blend slivers are fed together, with the total number of recycled polyester-cotton blend slivers being between 6 and 8. In the second drawing process, the fed recycled polyester-cotton blend slivers are divided into two groups, and the amount of recycled polyester in each group is kept completely consistent. They are fed into the second drawing device from back to front along the direction of fiber movement in the second drawing process.

[0047] The second drawing frame includes a feeding system, a drafting system, and a winding system. The feeding system includes an upper pressure roller pair and a lower pressure roller pair. The upper and lower pressure roller pairs of the feeding system for the second drawing frame are exactly the same as those of the feeding system for the first drawing frame. An upper rear gathering bell mouth is provided on the rear side of the upper pressure roller pair, and a lower rear gathering bell mouth is provided on the rear side of the lower pressure roller pair. The upper and lower rear gathering bell mouths of the second drawing frame are exactly the same as those of the first drawing frame.

[0048] The drafting system includes a rear drafting roller pair, a middle drafting roller pair, and a front drafting roller pair. The rear drafting roller pair includes a rear lower roller and a rear upper roller. The middle drafting roller pair includes a middle lower roller and a middle upper roller. The front drafting roller pair includes a front lower roller and a front upper roller. The rear upper roller, middle upper roller, and front upper roller are mounted on a pressure assembly, which is spring-loaded. When the pressure assembly presses down, it causes pressure to be applied between the rear lower roller and the rear upper roller, and between the middle lower roller and the middle upper roller. The front lower roller and the front upper roller are pressed into contact respectively. When the pressure assembly is raised, a certain distance is maintained between the rear lower roller and the rear upper roller, between the middle lower roller and the middle upper roller, and between the front lower roller and the front upper roller. A front gathering trumpet is provided at the front of the drafting system. The front gathering trumpet of the second drawing is exactly the same as that of the first drawing. The coiling system of the second drawing is exactly the same as that of the first drawing.

[0049] During use, the upper and lower rollers of the upper pressure roller pair, the upper and lower rollers of the lower pressure roller pair, the rear lower roller and rear upper rubber roller of the drafting system, the middle lower roller and middle upper rubber roller of the drafting system, the front lower roller and front upper rubber roller of the drafting system, and the front upper roller and front lower roller of the front pressure roller pair are all stopped and maintained at a certain distance. The first set of recycled polyester-cotton blended sliver is passed sequentially through the upper and rear gathering bell mouth, between the upper and lower rollers of the upper pressure roller pair, between the rear lower roller and rear upper rubber roller of the drafting system, between the middle lower roller and middle upper rubber roller of the drafting system, between the front lower roller and front upper rubber roller of the drafting system, between the front upper roller and front lower roller of the front pressure roller pair, and the front gathering bell mouth. The second set of recycled polyester-cotton blend slivers is passed through the trumpet opening, between the upper and lower rollers of the lower pressure roller pair, between the rear lower roller and rear upper rubber roller of the drafting system, between the middle lower roller and middle upper rubber roller of the drafting system, between the front lower roller and front upper rubber roller of the drafting system, between the front upper roller and front lower roller of the front pressure roller pair, and then through the front trumpet opening to complete the initial setup. Then, the upper and lower rollers of the upper pressure roller pair, the upper and lower rollers of the lower pressure roller pair, the rear lower roller and rear upper rubber roller of the drafting system, the middle lower roller and middle upper rubber roller of the drafting system, the front lower roller and front upper rubber roller of the drafting system, and the front upper roller and front lower roller of the front pressure roller pair are passed through. Both sets are configured to remain rotating and pressing against each other. During this process, the first and second sets of recycled polyester-cotton blend slivers are fed into the drafting system through the upper and lower rear gathering bell mouths, respectively. During feeding, the first and second sets of recycled polyester-cotton blend slivers gradually transform from a cylindrical shape to a horizontal planar shape, and gradually merge during this transformation. After merging, the first and second sets of recycled polyester-cotton blend slivers are pressed and fed together by the rear lower roller and rear upper rubber roller of the drafting system's rear drafting roller pair. The pressing process results in a relatively tight... The first and second sets of recycled polyester-cotton blend slivers are fed into the drafting system in an overlapping manner. Within the drafting system, the drafting action creates gaps between the fibers in the first and second sets of recycled polyester-cotton blend slivers. Then, under the pressing action of the drafting system, the fibers between the two sets randomly permeate each other, resulting in a semi-cooked recycled polyester-cotton blend sliver that is approximately planar. After passing through the front gathering bell mouth, the semi-cooked recycled polyester-cotton blend sliver gradually transforms from a planar state back into a spatial cylindrical structure before being output. The output semi-cooked recycled polyester-cotton blend sliver is then wound into a sliver can by a winding disc.

[0050] In the third drawing process, 4-6 strands of recycled polyester-cotton blended semi-finished sliver are fed together and fed into the third drawing device from back to front along the direction of fiber movement in the third drawing process.

[0051] The third drawing assembly includes a feeding system, a drafting system, and a winding system. The feeding system includes a rear gathering bell, which is identical to the upper and lower rear gathering bells of the second drawing assembly. The drafting system of the third drawing assembly is identical to that of the second drawing assembly. A front gathering bell is located at the front of the drafting system, identical to that of the second drawing assembly. The winding system of the third drawing assembly is identical to that of the second drawing assembly. During use, the following settings are provided: The rear lower roller and rear upper roller, middle lower roller and middle upper roller, and front lower roller and front upper roller of the drafting system are all stopped and maintained at a certain distance. Four to six strands of recycled polyester-cotton blended semi-finished sliver are sequentially passed through the rear gathering bell mouth, between the rear lower roller and rear upper roller of the drafting system, between the middle lower roller and middle upper roller of the drafting system, between the front lower roller and front upper roller of the drafting system, and through the front gathering bell mouth, thus completing the initial setup. Then, the rear lower roller and rear upper roller, middle lower roller and middle upper roller, and front lower roller and... Both front and upper rubber rollers are rotating and pressing against each other. During this process, 4-6 recycled polyester-cotton blend semi-cooked slivers are arranged parallel to each other along the width of the blend and enter the rear gathering trumpet opening. As the diameter of the gathering trumpet opening decreases, the fed recycled polyester-cotton blend semi-cooked slivers bulge vertically. Then, as the centrifugal force increases, the bulging part is pressed down again, thereby gradually compressing and merging the recycled polyester-cotton blend semi-cooked slivers along the width of the blend, making the 4-6 fed recycled polyester-cotton blend semi-cooked slivers approximately planar. The recycled polyester sliver is fed tightly into the drafting system. The tight structure within the drafting system causes frictional forces between the fibers in the recycled polyester sliver. Under the control of the force field generated by this frictional force, the fibers move in a stable and concentrated variable speed control within the drafting zone, resulting in a recycled polyester sliver with a more uniform linear density distribution. After passing through the front gathering bell mouth, the recycled polyester sliver gradually transforms from a planar state back into a spatial cylindrical structure before being output. The output recycled polyester sliver is then wound into the sliver can by the winding disc.

[0052] (3) Yarn making: The recycled polyester cotton sliver obtained in step (2) is successively processed through roving, spinning and winding processes to obtain recycled polyester and cotton blended yarn.

[0053] In the roving process, a recycled polyester sliver is fed in and sequentially drafted, twisted, and wound to obtain recycled polyester roving. The drafting system adopts a four-roller double short apron structure. A guide frame for feeding the recycled polyester sliver is located at the rear of the drafting system. The guide frame uses a grooved aluminum alloy overhead guide device. A cleaning device is located above the drafting system, employing an intermittent upper and lower cleaning device with a comb-type rotating cloth belt. During the winding process, the lower bobbin drive uses a group drive, 12 spindles / group, thus enabling multi-spindle roving frames. Full-bore doffing is achieved using an external automatic doffing system, which can be used independently as an automatic doffing roving frame or in conjunction with a roving conveyor system to achieve roving-to-fine yarn connection and winding. During the process, the centrifugal force of the roving is kept constant automatically, and the spinning speed is automatically adjusted to reduce yarn breakage. In the spinning process, a recycled polyester-cotton roving is fed in and then sequentially drafted and twisted to obtain recycled polyester and cotton blended bobbin yarn. The spindle drive in the twisting process adopts a single belt drive method, with 1200 spindles using one belt, which is driven by 10 variable frequency motors. The drafting system in the drafting process uses a separate variable frequency motor, and the ring rail lifting is carried out by a servo motor, which is precisely detected and controlled by an absolute encoder. The coordination and control between all speeds is completed by PLC. In the winding process, the recycled polyester and cotton blended bobbin yarn is rewound to obtain a large package of recycled polyester and cotton blended bobbin yarn with reduced yarn defects.

Claims

1. A method for producing recycled polyester and cotton blended yarn, characterized in that, Includes the following steps: (1) Cleaning and combing: Selected recycled polyester fibers and cotton fibers are processed into recycled polyester sliver and cotton sliver through their respective cleaning and combing processes; For recycled polyester fiber: Selected recycled polyester fiber is sequentially processed through disc cotton grabbing, metal Mars dual-purpose detector, multi-compartment cotton blending, cotton opening, and carding to obtain recycled polyester sliver. For cotton fibers: Selected mixed cotton fibers are sequentially passed through a disc cotton grabber, a metal-Mars dual-purpose detector, an airflow separator, a heavy object separator, a single-axis flow cotton opening, a multi-compartment cotton blending, a porcupine cotton opening, a cotton spinning foreign fiber removal machine, and a carding machine to obtain cotton sliver. During the cotton blending process, airflow mixing, layer mixing, and intensive mixing are used sequentially to thoroughly mix the selected cotton fibers or recycled polyester fibers. (2) Mixing: The recycled polyester sliver obtained in step (1) is pre-dated to obtain recycled polyester pre-dated sliver, and the cotton sliver is pre-dated to obtain cotton pre-dated sliver. The recycled polyester pre-dated sliver and the cotton pre-dated sliver are then combined through three dating processes to obtain recycled polyester cotton sliver. First drawing: An even number of recycled polyester pre-drawing slivers and an even number of cotton pre-drawing slivers are fed together, with the total number of recycled polyester pre-drawing slivers and cotton pre-drawing slivers fed being between 4 and 8. The fed recycled polyester pre-drawing slivers and cotton pre-drawing slivers are divided into two groups, and the number of recycled polyester pre-drawing slivers and cotton pre-drawing slivers in each group is the same. They are fed from back to front along the direction of fiber movement in the first drawing and fed into the feeding system, drafting system and winding system of the first drawing device to obtain a recycled polyester cotton blend sliver. The first drawing assembly includes a feeding system, a drafting system, and a winding system. The feeding system includes an upper pressure roller pair and a lower pressure roller pair. An upper rear gathering bell mouth is located behind the upper pressure roller pair, and a lower rear gathering bell mouth is located behind the lower pressure roller pair. The upper and lower rear gathering bell mouths have identical structures, and their cross-sections are elliptical. Along the length direction of the upper and lower rear gathering bell mouths, the length of the major axis of the ellipse gradually decreases from back to front. As the heart rate gradually increases, the upper and lower pressure roller pairs have identical structures. Each pair includes an upper roller and a lower roller, with the lower roller driven by a corresponding transmission mechanism. Both the upper and lower rollers include an intermediate roller shaft, which is a solid cylindrical steel structure. A lower roller sleeve is fitted onto the intermediate roller shaft of the lower roller, and the lower roller sleeve is fixedly connected to the intermediate roller shaft. An upper roller sleeve is fitted onto the intermediate roller shaft of the upper roller, and the upper roller sleeve is connected to the intermediate roller shaft of the upper roller via a needle roller bearing. Both the upper and lower roller sleeves are made of hard rubber. The intermediate roller shaft of the lower roller of the lower pressure roller pair is driven to rotate by a corresponding transmission mechanism. The intermediate roller shafts of the lower rollers of the upper pressure roller pair are connected to each other via belt drives. The intermediate roller shafts of the upper rollers of the upper pressure roller pair and the intermediate roller shafts of the upper rollers of the lower pressure roller pair are connected by corresponding pressure rods. The upper end of the pressure rod is connected to the intermediate roller shaft of the upper roller of the upper pressure roller pair via an upper spring pressure assembly, and the lower end of the pressure rod is connected to the intermediate roller shaft of the upper roller of the lower pressure roller pair via a lower spring pressure assembly. The upper and lower spring pressure components have the same structure. When the pressure rod is pressed down with a certain pressure, the upper and lower spring pressure components are in a pressurized and locked state, thereby maintaining a certain pressure contact between the upper and lower rollers of the upper pressure roller pair and between the upper and lower rollers of the lower pressure roller pair. When the pressure rod is pulled up with a certain pressure, the upper and lower spring pressure components are in an extended and locked state, thereby maintaining a certain distance between the upper and lower rollers of the upper pressure roller pair and between the upper and lower rollers of the lower pressure roller pair. The drafting system includes an upper drafting system and a lower drafting system. The upper drafting system is located in front of the upper pressure roller pair, and the lower drafting system is located in front of the lower pressure roller pair. The upper and lower drafting systems have the same structure. Both systems include a rear drafting roller pair, a middle drafting roller pair, and a front drafting roller pair. The rear drafting roller pair includes a rear lower roller and a rear upper roller. The middle drafting roller pair includes a middle lower roller and a middle upper roller. The front drafting roller pair includes a front lower roller and a front upper roller. The rear upper roller, middle upper roller, and front upper roller of the lower drafting system maintain a certain distance from the rear lower roller, middle lower roller, and front lower roller of the upper drafting system, respectively. The rear lower roller, middle lower roller, and front lower roller of the upper drafting system are respectively positioned relative to the rear lower roller, middle lower roller, and front lower roller of the lower drafting system, respectively. The front and lower rollers are connected by a belt drive. The rear upper roller, middle upper roller, and front upper roller of the upper drafting system are connected to the rear upper roller, middle upper roller, and front upper roller of the lower drafting system via pressure transmission connecting rods. Pressure rods are installed between the rear upper roller, middle upper roller, and front upper roller of the upper drafting system. When the pressure rods are on the platform, the rear upper roller, middle upper roller, and front upper roller of the upper drafting system maintain a certain distance from the rear lower roller, middle lower roller, and front lower roller of the upper drafting system, respectively. At this time, the rear upper roller, middle upper roller, and front upper roller of the upper drafting system, through corresponding pressure transmission connecting rods, maintain a certain distance from the rear upper roller, middle upper roller, and front lower roller of the lower drafting system, respectively. At a fixed interval, when the pressure rod presses down, the upper rear roller, middle upper roller, and front upper roller of the upper drafting system press tightly against the lower rear roller, middle lower roller, and front lower roller of the upper drafting system, respectively. At this time, the upper rear roller, middle upper roller, and front upper roller of the upper drafting system, through corresponding pressure transmission connecting rods, ensure that the lower rear roller, middle upper roller, and front upper roller of the lower drafting system press tightly against the lower rear roller, middle lower roller, and front lower roller of the lower drafting system, respectively. A pair of front pressure rollers is arranged in the middle in front of the upper and lower drafting systems. The pair of front pressure rollers includes an upper front roller and a lower front roller. The upper front roller and the lower front roller have the same structure and include an intermediate shaft. A pressing sleeve is fitted on the intermediate shaft, and the pressing sleeve is connected to the intermediate shaft through a bearing, allowing the pressing... The pressure sleeve rotates freely around the intermediate shaft. The intermediate shafts of the upper front roller and the lower front roller are connected by a knob-type pressing assembly. The knob-type pressing assembly includes an upper pressure spring and a lower pressure spring, which are connected by a pressing knob. When a certain force is applied and the pressing knob is rotated counterclockwise, the pressing knob is closed, thus putting the upper and lower pressure springs under elastic tension, thereby keeping the upper and lower front rollers pressed tightly together. When a certain force is applied and the pressing knob is rotated clockwise, the pressing knob is opened, thus putting the upper and lower pressure springs under natural extension, thereby maintaining a certain distance between the upper and lower front rollers. A front gathering trumpet is provided at the front of the front pressure roller pair, and the cross-section of the front gathering trumpet is an elliptical structure.Along the length of the front converging flare, from back to front, the length of the major axis of the ellipse in the cross-section gradually decreases, and the eccentricity gradually decreases, causing the output recycled polyester-cotton blend strips to gradually merge and recombine from a planar state back into a spatial ellipse; The winding system includes a coiling disc, a base plate, and a sliver. The sliver is a hollow cylinder with an open top. The bottom of the sliver is closed and embedded in the base plate. A coiling spring is fixed on the base plate of the sliver. The lower end of the coiling spring is fixed to the circular surface at the bottom of the sliver. A release disc is provided at the upper end of the coiling spring. The release disc has a circular structure and the diameter of the coiling disc is smaller than the diameter of the sliver. The coiling disc is driven to rotate by a corresponding transmission mechanism. The base plate is driven to rotate by a corresponding transmission mechanism. The rotation direction of the coiling disc is the same as that of the base plate. The first and second groups of recycled polyester and cotton pre-drawing slivers are fed into the upper and lower drafting systems via upper and lower gathering bell mouths, respectively. This causes the first and second groups of recycled polyester and cotton pre-drawing slivers to gradually transform from a spatial cylindrical shape to a horizontal planar shape, gradually merging during the transformation. After merging, the first group of recycled polyester and cotton pre-drawing slivers is further transformed into a planar shape by pressing with the upper pressure roller and fed into the upper drafting system. After drafting in the upper drafting system, a first recycled polyester-cotton blend sliver with reduced linear density is obtained. Due to the reduced linear density, a certain gap is maintained between the fibers. The merged second group of recycled polyester and cotton pre-drawing slivers are then pressed by the lower pressure roller. The material is then further transformed into a planar shape and fed into the lower drafting system. After drafting in the lower drafting system, a second recycled polyester-cotton blend sliver with reduced linear density is obtained. Due to the reduction in linear density, a certain gap is maintained between the fibers. The first and second recycled polyester-cotton blend slivers are pressed together by the front pressure rollers. During the pressing process, the fibers in the first and second recycled polyester-cotton blend slivers are interlocked, realizing the random mixing between recycled polyester fibers and cotton fibers, resulting in a planar structure of recycled polyester-cotton blend sliver. After passing through the front gathering bell mouth, it gradually transforms from a planar state back into a spatial cylindrical structure before being output. The output recycled polyester-cotton blend sliver is then wound into the sliver can by the winding disc. Second drawing: An even number of recycled polyester-cotton blend slivers are fed together, with the total number of recycled polyester-cotton blend slivers being between 6 and 8. In the second drawing, the fed recycled polyester-cotton blend slivers are divided into two groups, and the amount of recycled polyester in each group is the same. The fibers are fed from back to front into the feeding system, drafting system and winding system of the second drawing device along the direction of fiber movement in the second drawing to obtain a recycled polyester-cotton blend semi-cooked sliver. The second drawing frame includes a feeding system, a drafting system, and a winding system. The feeding system includes an upper pressure roller pair and a lower pressure roller pair. The upper pressure roller pair and the lower pressure roller pair of the feeding system of the second drawing frame are exactly the same as those of the feeding system of the first drawing frame. An upper rear gathering bell mouth is provided on the rear side of the upper pressure roller pair, and a lower rear gathering bell mouth is provided on the rear side of the lower pressure roller pair. The upper rear gathering bell mouth and the lower rear gathering bell mouth of the second drawing frame are exactly the same as those of the first drawing frame. The drafting system includes a rear drafting roller pair, a middle drafting roller pair, and a front drafting roller pair. The rear drafting roller pair includes a rear lower roller and a rear upper roller. The middle drafting roller pair includes a middle lower roller and a middle upper roller. The front drafting roller pair includes a front lower roller and a front upper roller. The rear upper roller, middle upper roller, and front upper roller are mounted on a pressure assembly, which is spring-loaded. When the pressure assembly presses down, it causes pressure to be applied between the rear lower roller and the rear upper roller, and between the middle lower roller and the middle upper roller. The front lower roller and the front upper roller are pressed into contact respectively. When the pressure assembly is raised, a certain distance is maintained between the rear lower roller and the rear upper roller, between the middle lower roller and the middle upper roller, and between the front lower roller and the front upper roller. A front gathering trumpet is provided at the front of the drafting system. The front gathering trumpet of the second drawing is exactly the same as that of the first drawing. The coiling system of the second drawing is exactly the same as that of the first drawing. The first and second groups of recycled polyester-cotton blend slivers are fed into the drafting system through the upper and lower rear gathering bell mouths, respectively. During the feeding process, the first and second groups of recycled polyester-cotton blend slivers gradually change from a spatial cylindrical shape to a horizontal planar shape, and gradually merge during the transformation. After merging, the first and second groups of recycled polyester-cotton blend slivers are fed together through the rear drafting rollers of the drafting system. During the pressing process, the relatively compact first and second groups of recycled polyester-cotton blend slivers are fed into the drafting system in an overlapping state. In the drafting system, due to the drafting action, gaps are created between the fibers in the first and second groups of recycled polyester-cotton blend slivers. Under the pressing action of the drafting system, the fibers between the two groups randomly permeate each other, resulting in a recycled polyester-cotton blend semi-cooked sliver with an approximately planar state. After passing through the front gathering bell mouth, it gradually changes from a planar state back to a spatial cylindrical structure before being output. The output recycled polyester-cotton blend semi-cooked sliver is then wound into the sliver can by the winding disc. The third drawing process involves feeding 4-6 recycled polyester cotton mixed semi-finished slivers together, and feeding them from back to front into the feeding system, drafting system and winding system of the third drawing device along the direction of fiber movement in the third drawing process to obtain recycled polyester cotton finished sliver. The third drawing assembly includes a feeding system, a drafting system, and a winding system. The feeding system includes a rear gathering bell, which is identical to the upper and lower rear gathering bells of the second drawing assembly. The drafting system of the third drawing assembly is identical to that of the second drawing assembly. A front gathering bell is located at the front of the drafting system, and this front gathering bell is identical to that of the second drawing assembly. The winding system of the third drawing assembly is identical to that of the second drawing assembly. The winding systems for drawing slivers are completely identical. During operation, the rear lower roller and rear upper roller, middle lower roller and middle upper roller, and front lower roller and front upper roller of the drafting system are all stopped and maintained at a certain distance. Four to six strands of recycled polyester-cotton blended semi-finished sliver are sequentially passed through the rear gathering bell mouth, between the rear lower roller and rear upper roller of the drafting system, between the middle lower roller and middle upper roller of the drafting system, between the front lower roller and front upper roller of the drafting system, and finally through the front gathering bell mouth, thus completing the initial winding process. Initially, the rear lower roller and rear upper roller, middle lower roller and middle upper roller, and front lower roller and front upper roller of the drafting system are all set to rotate and press against each other. During this process, 4-6 recycled polyester-cotton blend semi-finished slivers are arranged parallel to each other along the width direction of the blend and enter the rear gathering trumpet opening. As the diameter of the gathering trumpet opening decreases, the fed recycled polyester-cotton blend semi-finished slivers bulge vertically. Then, as the centrifugal force increases, the bulging part is pressed down again, causing... Four to six recycled polyester cotton blend semi-finished slivers are fed into the drafting system in an approximately planar and compact manner. The compact structure within the drafting system causes frictional forces between the fibers in the recycled polyester cotton blend semi-finished sliver, resulting in a recycled polyester cotton finished sliver with a more uniform linear density distribution. After passing through the front gathering trumpet, the recycled polyester cotton finished sliver gradually transforms from a planar state back into a spatial cylindrical structure before being output. The output recycled polyester cotton finished sliver is then wound into the sliver can by the winding disc. (3) Yarn making: The recycled polyester cotton sliver obtained in step (2) is successively processed through roving, spinning and winding processes to obtain recycled polyester and cotton blended yarn.

2. The method for producing recycled polyester and cotton blended yarn according to claim 1, characterized in that, The raw materials used in the cleaning and combing process of the recycled polyester fiber in step (1) include 96.19% recycled polyester with a specification of 1.4D*38mm, 1.27% ECO / C suction flower, 1.27% ECO / C mixed strip, and 1.27% ECO / C roving end.

3. The method for producing recycled polyester and cotton blended yarn according to claim 1, characterized in that, The raw materials used in the cotton fiber cleaning and carding process described in step (1) include: 11.11% Grade 328, 9.1% moisture regain, and 4.69 micronaire value Aksu cotton; 11.11% Grade 328, 8% moisture regain, and 4.56 micronaire value Aksu cotton; 11.11% Grade 328, 8.8% moisture regain, and 4.72 micronaire value Urumqi cotton; and 11.11% Grade 328, 8.8% moisture regain, and 4.79 micronaire value Aksu cotton. The following grades of cotton are listed: Grade 328, moisture regain 8.3%, micronaire value 4.94 (Aksu cotton); Grade 328, moisture regain 9.3%, micronaire value 4.85 (Kuitun cotton); Grade 328, moisture regain 8.4%, micronaire value 3.91 (Wanxing cotton); Grade 328, moisture regain 8.9%, micronaire value 4.71 (Aksu cotton); Grade 328, moisture regain 8.2%, micronaire value 4.68 (Aksu cotton).

4. The method for producing recycled polyester and cotton blended yarn according to claim 1, characterized in that, In step (1), the opening of the recycled polyester fiber is achieved by gripping and striking, while the opening of the cotton fiber is achieved by free striking and gripping striking.

5. The method for producing recycled polyester and cotton blended yarn according to claim 1, characterized in that, Preparation of cotton pre-drawing: Eight cotton slivers are arranged in parallel along the thickness direction and fed together. The eight cotton slivers are then combined through a trumpet and enter the drafting system for drafting. The drafting ratio is set between 8.05 and 8.

3. After drafting, the cotton pre-drawing is obtained by bundling with a bundler. Preparation of recycled polyester pre-drawn sliver: Six recycled polyester slivers are arranged parallel to each other along the thickness direction and fed together. The six recycled polyester slivers are then combined through a bell mouth and enter the drafting system for drafting. The drafting ratio is set between 5.8 and 6.

0. After drafting, the slivers are bundled by a bundler to obtain the corresponding recycled polyester pre-drawn sliver. The drafting system adopts a three-upper-three-lower pressure bar with guide rollers. The lower roller is made of special steel material and adopts advanced heat treatment technology. Both upper and lower roller bearings are high-precision needle roller bearings.