1 Concept of differentiated fiber and spinning characteristics
1.1 Differentiated fibers
Differentiated fibers refer to chemical fibers that are different from conventional chemical fibers, and change their fiber structure, shape and other characteristics through chemical and physical means to make them have certain functional characteristics. Mainly include bi-antibody, expanded body, special cross-section (cross, triangle, flat, dumbbell, three-leaf, etc.), ultra-fine denier, anti-pilling, colored fiber, activated carbon fiber, nano and high flame retardant, beauty and skin care, and human body regulation Multifunctional composite fibers such as microcirculation.
1.2 Functional fibers
Functional fibers refer to fibers that have other special functions in addition to the physical and mechanical properties of conventional fibers. The so-called special functions refer to reverse osmosis, separation of mixed gases, dialysis, ultrafiltration, adsorption, oil absorption, ion exchange, high-efficiency filtration, light guide and conduction, etc. Functional fibers have been applied in the textile industry with their respective special functions. The development of functional fibers is a symbol of the progress of modern fiber science.
1.3 Special non-cotton natural fibers
Natural fibers are grown or formed in nature and are suitable for textile fiber materials, including natural plant fibers, animal protein fibers, and mineral fibers. According to the classification of spinning industry, there are four types of cotton spinning (including chemical fiber), wool spinning, hemp spinning, and silk spinning. Each type of spinning enterprise has different equipment forms and technical requirements. In the cotton spinning industry, fine-staple cotton and long-staple cotton are usually used as natural plant fibers, which are suitable for the characteristics of the cotton spinning industry and are widely used. Flax and ramie are natural plant bast fibers, cashmere, cashmere, and camel hair are natural animal protein hair fibers, and mulberry silk and spun silk are natural animal protein gland fibers. It is difficult to spin in the cotton spinning industry, and its application is relatively small , but it is often used in high-quality cotton products.
1.4 Differential fiber spinning characteristics
Differentiated fibers include functional fibers and special non-cotton natural fibers, hereinafter referred to as differentiated fibers. The electrostatic properties, cohesion, fiber strength, fineness, length, color, moisture regain and other characteristics of various fibers vary greatly. Differential fiber yarn spinning is characterized by multiple varieties, small batches, and many varieties. It can be blended with a variety of acrylic fibers to form single-dyeing, double-dyeing and over-dyeing finished products, which have higher requirements for spinning quality. The spinning performance of differentiated fibers is relatively low (including special non-cotton natural fibers), and suitable spinning conditions for differentiated fibers must be created to meet and adapt to the spinning needs of differentiated fibers.
2 Key points and solutions of spinnability control of differentiated fibers
2.1 Differentiated fibers with high static electricity
Combining with the characteristics of differentiated fibers, take different measures to tackle key problems, eliminate unfavorable factors of spinnability, and ensure the spinning production needs of various differentiated fibers. For differentiated fibers with high static electricity, it is necessary to add Dianling IP to the fiber for moisture and health treatment to eliminate fiber static electricity. For example, milk protein modified fiber is a new type of fiber that is different from natural fibers, regenerated fibers and synthetic fibers. Its volume specific resistance is 4.7×1011 Ω·cm. Before spinning, an antistatic agent must be added in proportion and kept for 48 hours to eliminate static electricity in the fiber, otherwise it will be difficult to spin.
2.2 Fibers with poor cohesion
The fiber cohesion can reflect the curling characteristics of the fiber and has a great influence on the spinnability. During the opening and carding process of fibers with good cohesion, the fibers are easily gathered together by the cohesion between fibers. Fibers with low cohesion are loose and difficult to gather together, and the cotton net will sag or fall into the net, making spinning difficult. The cohesion of fibers is strong, the friction between fibers is increased, and the yarn has a certain pulling force to synthesize and gather, and it is not easy to break. Flax fibers are thick, rigid and brittle, and have poor cohesion, so it is difficult to roll them into strips alone. For the spinning of such fibers with poor cohesion, it needs to be blended with fibers with good cohesion. For example, flax fiber can be blended with cotton, polyester, viscose, modal, lyocell and other fibers to produce different proportions of flax blended yarn, and the spinning process is smooth, and the yarn index is significantly improved. In addition, because the flax fiber is brittle and easy to break during the spinning process, it is advisable to apply moisture to the flax fiber to control the moisture regain of the fiber at about 18%. At the same time, increase the temperature and humidity of the spinning machine environment, and if necessary, set up tents in the production machine area to maintain suitable temperature and humidity, and spray and add water to give humidity.
2.3 Fibers with large differences in properties
The characteristics, whiteness and coloring performance of differentiated fibers are quite different. From the input of raw materials to each production process, the storage and use of each semi-finished product and the management of flower return, it is necessary to do a good job of isolation and protection, and it is strictly forbidden to cause quality hazards caused by mixed fibers. For example, 2.5% biomass graphene modified viscose fiber (referred to as graphene fiber) has a specification of 1.33 dtex×38 mm and a whiteness of 4.5%, which is black fiber. Graphene fiber blended yarn belongs to both functional fiber yarn and Color spun yarn. When the fiber raw material is put into the workshop for production, strict isolation and protection measures must be taken to prevent the fibers from floating and causing mixed fibers and polluting other yarn varieties.
2.4 Variety identification of differentiated yarns
In addition to colored fibers, differentiated fiber yarns are mostly off-white in color. Due to the multi-variety and small-batch variety structure of differentiated fibers, it is difficult to identify the variety of this white yarn. Unlike colored spinning varieties, it is easier to distinguish varieties by color. In order to facilitate the identification of differentiated fiber and yarn varieties in the production and manufacturing process, each process canister container and bobbin packaging equipment are distinguished by different colors and patterns (color heads), that is, one color or pattern (color head) Represents a type of yarn, and strictly prevents quality accidents of the wrong type.
2.5 Quality problems caused by different dyeing methods
Acrylic blends are dyed by different dyeing methods such as single dyeing, double dyeing, and over-dyeing. Most of the acrylic raw materials are left blank and not colored, but sometimes a low proportion of modal or viscose raw materials are left blank and not colored. During the production process of the yarn, due to problems in the process, operation, equipment, raw materials, etc., there are yarn defects in the yarn. The quality problem exposed is the formation of white stars and stripes on the cloth surface, and these defects are harmful. defect. Therefore, in the spinning and weaving process, effective measures must be taken to strengthen the effective prevention and control of these defects.
3 Application of advanced spinning technology in differential fiber spinning
3.1 Siro compact spinning technology
3.1.1 Characteristics of Siro compact spinning
Siro compact spinning combines the advantages of compact spinning and siro spinning. Siro compact spinning has the advantages of high single yarn strength, uniformity, compact structure, good wear resistance, less hairiness, and smooth yarn. Line style, but also single yarn properties. The quality indicators of Siro compact spinning are significantly improved compared with ordinary ring spinning. At the same time, it can also reduce the amount of yarn sizing and environmental pollution in the desizing process, improve the efficiency of looms, and cancel the singeing process. The fabric woven with Siro compact spinning yarn has clear texture, good gloss, wear resistance and is not easy to pilling.
3.1.2 Differential yarn defect control
To produce differentiated fiber and yarn varieties using Siro compact spinning technology, the control of compact spinning and drafting components should be strengthened to prevent "bumpy yarn" defective products. When adopting YHJMF four-roller compact spinning device, the selection of the diameter configuration of the small rollers is very critical, and the diameter of the small rollers should be selected according to the type of fiber to be spun. When producing differentiated fiber yarn, it is advisable to control the diameter of the small roller too large (above 18.7 mm), otherwise drafting will not be smooth. In case of yarn doffing or temporary parking, the negative pressure fan must be turned off, otherwise, a large amount of dust will accumulate in the suction groove of the special-shaped pipe, and it will be attached to the whiskers in the accumulation area, resulting in "slub yarn"-like soot defects on the whole machine yarn. The longer the parking time, the more obvious the soot defect yarn will be.
3.1.3 Key points of management and control of Siro compact spinning compact area
Strengthen the management of the concentrated area of Siro compact spinning, and keep the two yarns in the concentrated area clear and stable. Once the yarn sliver is fuzzy, shakes or becomes a single strand, it will seriously affect the spinning quality, and it is easy to cause "bumpy yarn", neps, thick spots and hairiness increase, and the strength decreases. It should be checked whether the bell mouth is out of position, whether the pressure of the cradle is too small, whether the screws of the cradle are loose, whether the negative pressure pipe joint is detached and leaking air, whether the suction groove of the special-shaped tube cover plate is clogged, whether the tension hook is deformed or entangled, Check whether the grid ring is damaged, whether the transmission gear has accumulated flowers, missing teeth and other bad phenomena. The compact spinning negative pressure fan must be linked with the spinning main machine, otherwise, when the negative pressure fan stops, the spinning main machine will not stop, and a large amount of "bumped yarn" will be generated.
3.1.4 Reducibility of Siro compact spinning mechanism
The Siro compact spinning machine and the Siro spinning machine can be restored and converted. When the Siro compact spinning machine needs to produce Siro spinning varieties, the special-shaped tube, the negative pressure connecting pipe, and the compacting roller can be removed to restore the Siro spinning machine. Device spinning form. Conversely, when the Siro spinning machine needs to produce Siro compact spinning varieties, it is enough to install and restore the special-shaped tube, the negative pressure connecting tube, and the compacting roller. Since the Siro compact spinning has no yarn guide stroke, the cots and aprons are prone to concave phenomenon. In order to ensure that the surface of the cots and aprons has sufficient holding force on the fibers and does not cause entanglement, the replacement cycle of the aprons is 3 1, the regrinding period of the rubber rollers in front of the drafting area is 2 months, and the regrinding period of the rubber rollers in the agglomeration area and the rubber rollers after the drafting area is 6 months.
3.2 Blowing-carding technology
3.2.1 Process flow
Due to the characteristics of multi-variety and small batches of differentiated fiber yarns, the spinning process is mainly produced in rolls in the cotton cleaning process, and the production of blowing and carding processes is seldom used. At present, our company has successfully transformed 8 blowing and carding production lines. The original cleaning line has been changed to one machine and two lines. There are 10 carding machines in one row, which can produce 2 varieties at the same time. The specific technological process is as follows.
The first line: FA002A automatic plucking machine → SCR cotton condenser → BO?12 loose baler → CB2 cleaning machine → CFC automatic cotton supply system → JF1171C cotton box → A186G carding machine.
Second line: FA002A automatic plucking machine → FA022?6 multi-compartment blender → FA106 opener → CFC automatic cotton supply system → JF1171C cotton box → A186G carding machine.
3.2.2 Opening and adjustment of cotton feeding methods at both ends
A total of 10 carding machines with one machine and two lines adopt the method of cotton feeding at both ends, and can produce 2 varieties at the same time. According to the supply needs before and after, two types of carding machines can be added or subtracted at any time. The cotton supply system of the carding machine is installed between the cotton supply pipes of each carding machine, and there is a cut-off dredging ball valve, which can be adjusted according to the needs. That is to say, one machine with two lines has 10 carding machines, 8 of which can produce 1 variety, and the other 2 can produce another 1 variety; or 7 can produce 1 variety, and the other 3 can produce another 1 variety; and so on. One machine with two lines and 10 carding machines can also produce one variety or more than two varieties, and change the variety when necessary. By increasing the reserve cans, it can meet the needs of multi-variety production.
3.2.3 The working principle and characteristics of loose bale machine
The BO?12 loose bale machine is mainly suitable for small batch production, which consists of flat balers, oblique balers and beaters. The main function is to loosen the feed materials from coarse to fine, and then mix them. The advantage of mixing after the raw materials are loosened can make the mixing more uniform and fine. The BO?12 loose bale machine occupies a small area and can replace the lengthy and complicated process of traditional cotton cleaning. It has a simple structure, is easy to operate, and is convenient for maintenance. When changing the variety and batch number, the cleaning work is relatively simple, which can effectively avoid the mixed fiber and color difference problems caused by the mixing of different varieties of raw materials. The BO?12 loose bale machine has high flexibility, and can be equipped with a single beater or 3 beaters according to the specific processing raw materials and the requirements of opening and miscellaneous; Flower falling phenomenon, effectively saving raw materials.
3.2.4 Advantages of blowing-carding equipment and cleaning management
After the renovation of the blowing and carding equipment, the labor of the cleaning workers and roll pushing workers was reduced, the labor intensity of the carding workers was reduced, and the stands could be expanded. At the same time, after canceling the lap, the amount of returning flowers and electricity consumption are significantly reduced. Due to the application of carding leveling technology, the unevenness of card sliver weight can be controlled within 2%, which greatly improves the quality level of semi-finished products. In order to ensure that different types of fibers are not mixed, when the same blowing-carding unit produces different types of fibers in turn and changes types, from the FA002 type plucking machine to the JF1171C type cotton box, each machine and the connection of the pipeline must be cleaned strictly. Thoroughly clean the car according to the requirements; when it is not necessary to clean the car, the car must be cleaned, no agglomerated raw materials are allowed, and the problem of mixed fibers is strictly prevented.
3.3 Spinning subsidiary intelligent technology
3.3.1 Utilization of auxiliary light source
When producing differentiated fiber yarns with low whiteness such as graphene, black bamboo charcoal, and coffee carbon, it is difficult to identify and identify broken ends of the spun yarn. . In view of this situation, an auxiliary light source can be added to make the broken end of the spun yarn clearly visible. After adding auxiliary light source with laser light, the recognition ability of dark yarn breakage is obviously improved.
3.3.2 Use of spindle position scanner
The DW?1 spinning spindle position scanner with equivalent ETC intelligent identification technology and the special bobbin with built-in chips regularly check out the outdated spindles of the spinning frame, and carry out quality tracking and rectification in time to eliminate outdated spindles with quality alarms and reduce the quality between spindles difference, and keep the yarn quality stable and consistent. DW?1 Spinning Spindle Position Scanner is an alternative to sticking labels on the traditional bobbin or manually writing the spindle number to troubleshoot outdated spindles. It adopts a more intelligent, convenient and accurate way to automatically identify the bobbin spindle position and track and troubleshoot backwardness. The spindle can be traced forward to the roughing machine to eliminate the hidden danger of quality. Specific usage method: when the spun yarn is doffing, replace the special yarn bobbin containing the chip, use the DW?1 spinning spindle position scanner to scan each one and start the car, and send it to the automatic winder for production after the yarn is full, and find that there are abnormal quality spindles , can scan and identify the spindle position of the spinning frame through the scanner. After the inspection is completed, it is only necessary to clear the data of the original set machine, and then the special bobbin can be put into the next machine again.
3.3.3 Application of automatic intelligent doffing machine
The QZD?JMF?A automatic intelligent doffing machine is especially suitable for doffing of short spinning machines. The head retention rate is above 95%, and the intubation rate is above 99%. The doffing time of the 420-spindle spinning frame is within 80 s. It is used for both sides of the spinning frame, that is, the front and the rear of the spinning frame. The body of this doffer adopts 304
The stainless steel is integrally welded, and the screws will not loosen during use, and the fuselage will not be deformed; the whole machine is small in shape, light in weight, and the workers are convenient and flexible to operate; Labor intensity; the modular manipulator design makes the outer dimension of the manipulator very small, so that it can be used for compact spinning and ring spinning; the manipulator clamps the top of the bobbin and the vertical yarn pulling technology avoids the loss of the spindle and yarn during traditional doffing . The doffers are powered by environmentally friendly new energy lithium batteries strongly advocated by the state. Each doffer is equipped with two lithium batteries to ensure non-stop use, making the doffers more portable and humanized. The doffing machine is fully automated. When the spindle is pulled out during the yarn drawing process, the doffer will sense an alarm and stop automatically. The doffing machine is equipped with a touch screen, so that the parameters and fault alarms of each part can be displayed, and the operator can be prompted according to the abnormal situation during use, and the fault can be resolved in the shortest time.
3.3.4 Use of automatic color separation management machine
The LGJ200Y automatic color separation and management machine can be connected with various types of automatic winders. As an auxiliary machine of the winding machine, this machine is connected with the outlet of the winding machine conveyor belt, and automatically sorts the single-color or two-color or more empty tubes on a single winding machine according to the color of the bobbins, and automatically straightens the big and small heads. Place them in the corresponding bobbins, and at the same time automatically sort the bobbins (referring to the spun bobbins with a small amount of yarn) and full bobbins into their corresponding bobbins. The LGJ200Y automatic color separation and management machine has a simple and compact working structure, takes up less space, is easy to operate and maintain, has a low failure rate, and can effectively save labor and reduce labor intensity. It is a new type of special auxiliary equipment for spinning with electromechanical automatic integration, and its management efficiency is not less than 3 300 pieces/h.
3.3.5 Control of drafting strands
When the blended yarn is blended with a variety of fibers with large differences in length and fineness, it is recommended to use the upper pin of the saddle large front punch double pressure bar to strengthen the control of the draft of the spun yarn. When our company produces a certain 8-component blended yarn variety, after using the upper pin of the saddle big front punch type double pressure rod, a new "dynamic" friction circle is arranged in the front area to effectively control the running state of the fiber, and the strands The draft is more flexible and stretchable, greatly improving the yarn quality, increasing the level of evenness by nearly 1 percentage point, and reducing coarse details by more than 50%.
4 Differential fiber blended yarn quality
After extensive adoption of appropriate technical and management measures, various Siro compact spinning differentiated fiber blended yarns produced have been tested by the Textile Product Quality Supervision, Inspection and Testing Center, and all the items inspected meet the technical requirements of superior products in relevant industry standards. Such as acrylic/wormwood/viscose 60/20/20 11.8 tex Siro compact spinning, all the quality indicators inspected are in line with the technical requirements of high-quality products in the standard of FZ/T12051-2016 "Acrylic Viscose Fiber Blended Natural Yarn" . The completion of the quality indicators of the 4 kinds of differentiated fiber blended yarns is listed, see Table 1. Among them, variety A is acrylic/wormwood/viscose 60/20/20 11.8 tex Siro compact spinning, B is graphene/modal/acrylic 40/30/30 11.8 tex Siro compact spinning, C is Lysai Er/linen 80/20 14.8 tex siro spinning, D is acrylic/viscose/wool 60/33/7 14.8 tex siro compact spinning.
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The successful development of a number of differentiated fiber blended yarns has met the current domestic demand for functional yarns in the textile field, and has been well received by users when put into the market. The market has broad prospects and has achieved good economic and social benefits. Our company will further strengthen the blending ratio and production process research of differentiated fiber blended yarns, produce multi-series functional yarns, improve product quality, and expand production scale to meet market needs and enhance market competitiveness.
5 Conclusion
The development of differentiated fibers has created favorable conditions for the technological innovation of the traditional textile industry and the transformation to high-tech industries, and has contributed to the improvement of human living standards. In the production of differentiated fiber blended yarn, the characteristics of each blended fiber are very different, and the spinnability is relatively poor. In addition, the fiber type and the blended composition ratio are complex, and the yarn types are mostly, which adds to the spinning system engineering. Very difficult. It is necessary to fully understand and master the characteristics of various differentiated fibers, select and configure suitable spinning equipment, and conduct a large number of experiments and comparisons to optimize the appropriate differential fiber spinning equipment. For multi-component differential fiber spinning, in terms of special equipment selection and process parameter configuration, the fiber component with a large proportion should be considered first, and then other fiber combinations should be considered. Differentiated fiber spinning solutions. For special varieties, in combination with the actual situation, effective technologies and production measures should be taken to eliminate fiber static electricity, improve cohesion for moisture preservation, isolation and protection, use different colors (patterns) of various container materials to identify varieties and fiber mixing methods, etc. Improve the means and ability to analyze problems and solve difficult problems. Although the spinnability of differential fiber spinning is poor and the variety structure is complex, after optimizing the configuration of process parameters and realizing fine management of each process, high-quality differential fiber yarn will definitely be spun.
