Composite fiber is two or more polymer melts, which are divided by a special distribution plate and extruded through the same spinneret. There are hundreds of varieties of composite fibers, and there are many classification methods. According to the production method, they can be divided into composite spinning and blended spinning. According to the spinning form, there are 5 commonly used types: co-spinning type, side-by-side type, sheath-core type, Split type, island type. Polyester/nylon composite fiber not only has the advantages of nylon’s wear resistance, high strength, easy dyeing, and moisture absorption, but also has the advantages of polyester’s good elasticity, good shape retention, stiffness, and no ironing. Generally, composite spinning is mainly composed of polyester and nylon, with orange-shaped, rice-shaped and other special-shaped cross-sections. It has good hygroscopicity and is mainly used in cleaning products, home textiles, etc. In addition, the low melting point, flame retardant, antistatic and conductive functions of many fibers are also achieved through the special structure of composite spinning.
Polyester-nylon composite ultra-fine Fiber production technology
01 Production method of polyester-nylon composite ultrafine fiber
Polyester-nylon composite ultrafine fiber uses PET and PA The two polymers are melt-spun at a certain ratio during the production process due to their differences in chemical structure, as well as their weak interfacial bonding force and ability to separate from each other. Usually, antibacterial microfibers add antibacterial agents to chemical fibers in the form of blends or masterbatch additions to obtain durable antibacterial effects. Compared with antibacterial finishing technology, antibacterial fiber has good antibacterial effect and is durable. The fabric weaving, dyeing and finishing processes are simple, the fiber does not adhere to resin, and the finished fabric has a good feel. However, this method is highly technical and difficult, especially requiring high antibacterial agents. In addition, most organic antibacterial agents are not resistant to high temperatures and are difficult to use in melt spinning. However, inorganic antibacterial agents, such as antibacterial phosphates, glass, ceramics, oxides, etc., have unique high temperature resistance properties, mainly through the silver they contain. The antibacterial effect of metal ions such as copper and zinc can achieve antibacterial and deodorizing effects. Relevant domestic enterprises have applied antibacterial agents containing a mixture of silver-containing inorganic phosphates and metal oxides to the production of polyester-nylon composite microfibers, and used the production technology of blending antibacterial masterbatch and fiber slices to produce antibacterial polyester-nylon composites. Microfiber and antibacterial fabric. The antibacterial material uses inorganic antibacterial agents (a mixture of phosphates and metal oxides containing 3% silver, with an average particle size of 400nm), and the spinning-grade resin slices use domestic ultra-fine denier nylon slices and domestic ultra-fine denier polyester slices. The melt spinning method uses a masterbatch addition method to produce melt-spun antibacterial polyester-nylon (80/20) composite ultrafine fibers. Antibacterial masterbatch is added to the polyester component at a proportion of about 2% of the base material. The process route adopts composite fiber high-speed spinning technology and applies the POY-DTY two-step process to produce fibers with good physical and mechanical properties. The average single fiber of the fiber produced by this method is about 0.2dtex, which is equivalent to 1/5-1/10 of real silk. It can give the fabric good physical and chemical properties and has been promoted and applied in the textile cleaning products and clothing industries.
02 Application technology test of polyester-nylon composite microfiber
The antibacterial properties of industrially produced antibacterial polyester-nylon composite microfiber DTY filaments and their warp knitted fabric dyed products were tested. The antibacterial test adopts the Japanese JIS L 1902 standard and conducts antibacterial tests on Staphylococcus aureus, Pneumoniae and Escherichia coli respectively. The test results show that the antibacterial effects of the fiber and dyed finished fabrics have reached the blue and orange standards of the Japan Fiber Evaluation Technology Association. Standard requirements, with high antibacterial effect. This action shows that the antibacterial agent containing silver-containing inorganic phosphate and metal oxide micropowder mixture can be used in the industrial production of antibacterial polyester-nylon composite filament ultrafine fiber melt spinning, thus opening up a new way to produce functional and differentiated fibers. . The antibacterial superfine fiber produced using this antibacterial masterbatch melt spinning technology and the POY-DTY two-step process has good physical and mechanical properties and antibacterial effects. The technology is feasible, the process is reliable, and the finished warp knitted fabric has excellent quality indicators. The actual production of antibacterial microfibers has better solved the problem of fibers produced by inorganic antibacterial agents that are prone to discoloration. The color difference and yellowing index of the dyed finished products are in line with actual production requirements.
Warp knitted fabrics were mass-produced with antibacterial polyester and nylon microfibers, and their dyeing and finishing processes were studied. The quality of the dyed finished product is excellent. It was tested at 95°C using ISO standards. The shrinkage rate and color fastness indicators are in line with actual needs, especially the anti-shrinkage performance. In addition, a chemical fiber company in Guangdong Province has cooperated with the American Hills Company to successfully technologically transform the 12×8 traditional polyester POY spinning production line. The transformed production line can also produce island-type and split-type two-component composite fibers. The production is normal and stable, and the product quality fully meets the requirements. The company has also carried out technical cooperation with relevant companies in South Korea, Taiwan, China, etc. to transform the traditional polyester POY spinning production line to produce single-component ultrafine fibers. The goal is to make the single fiber fiber of the product less than or equal to 0.35dtex. In this way, there is a broad development space for using traditional polyester POY spinning production lines to produce polyester and nylon composite filament antibacterial microfibers and fabrics.
The fiber number of special yarn is far more than that of ordinary fiber, so the specific surface area of the fiber is much larger than that of ordinary fiber. Therefore, the microfiber fabric has excellent hygroscopicity and moisture conductivity, soft hand feeling and good drape. In addition, during the fiber opening process, some fibers will be broken, and the surface of the fabric will be covered with a layer of fiber lint, which will have a strong wooly feel. After the superfine fiber and cotton yarn are combined into a network, its anti-pilling performance is much better than that of ordinary filament fabrics. The addition of cotton fiber also makes the wear more comfortable and beautiful. From the appearance, the fabric has an obvious mixed-color flash effect. This fabric not only maintains the dimensional stability and easy-iron properties of conventional polyester filament fabrics, but also has the hygroscopicity and breathability of cotton fibers. It is an ideal new type of knitted fabric. The fabric is particularly suitable for T-shirts and casual clothing and has broad market prospects.
07 Other functional fabrics
Because polyester and nylon composite fibers are opened to form extremely fine fibers with special-shaped cross-sections, large specific surface areas and unique interface properties, they are widely used as high-performance absorbent towels, quick-drying towels, filter materials and functional papers. . Due to its fine monofilament linear density, microfiber yarn becomes very dense due to the large number of fibers in the cross-section. It will become even denser with a suitable organizational structure, so that it can be both windproof and windproof without any additional coating or film. Breathability requirements.
In recent years, due to excessive production capacity expansion in the polyester and nylon composite yarn industry, the relationship between supply and demand has reversed, and the market conditions have experienced certain changes. However, as the downstream efforts to develop new products increase, polyester-nylon composite yarn still has certain room for development. For example, polyester-nylon-cotton composite fabric can not only be used to make men’s and women’s jackets, but also windbreakers. It can be said to be a marketable fabric in winter. Polyester-nylon composite microfiber can develop its added value. For example, transfer printing on microfiber fabrics can overcome the problem of uneven coloring caused by the extremely large surface area of the fabric. Its authenticity rate is very high, and the dye transfer rate is also high. , the color fastness to washing can reach level 3. However, from the perspective of wrinkle recovery of ultrafine fibers, when the single fiber micronization exceeds a certain limit, it will have a negative impact. As the single fiber becomes thinner, the comprehensive mechanical properties of the fiber also change. Therefore, when considering the miniaturization of a single fiber, a comprehensive balance must be made to ensure that the hand feel is improved to the greatest extent, so as not to lose sight of one thing or the other. When the separation degree of polyester-nylon ultra-fine denier composite yarn in the fabric is high, the fabric will feel soft, otherwise the fabric will feel rough. Due to the differences in the properties of polyester and nylon, targeted post-processing techniques need to be developed. This is also a prerequisite for the wide application of ultra-fine polyester and nylon composite yarns. </p
