Production process of nylon non-woven fabric and selection of raw materials used
1. Thermal bonding nylon nonwoven fabric
The nylon non-woven fabric thermal bonding method is one of the largest varieties of nylon non-woven fabrics. It is generally mixed with other fibers by pure nylon staple fiber or nylon, and the fibers are connected to each other by a hot rolling process to form a flake material. The product has the characteristics of thin, soft, fine and elastic, and is a good base material for high-grade adhesive interlining. It is used for lining cloths such as silk, high-grade windbreaker and down garment. It is also possible to mix nylon staple fibers with a certain proportion of other fibers, and to form a relatively strong web by hot rolling or hot melt, and then embossed and post-treated. For example, DuPont's composite non-woven Inova series is made up of nylon, polyester, polypropylene, spandex and cotton fibers in different proportions. The resulting composite nonwoven fabric has a permanent pattern with good elasticity and guidance. The characteristics of sweat and breathability can be warmed or cool according to the adjustment of the ambient temperature. It is used in the production of clothing, light, comfortable, fit, and strong and wearable.
The polyester-polyester core-sheath staple fiber can also be made into a non-woven fabric by a thermal bonding process. The nylon 6 is used as the skin, and the polyester is used as the core for the composite spinning, thereby producing a stable quality nylon-polyester fiber. reduce manufacturing cost. The performance of Jindi composite short fiber is better than that of pure nylon 6 short fiber, the breaking strength increases, the elongation at break decreases, and the initial modulus increases. The composite fiber also retains the good hygroscopicity, dyeability and wear resistance of the nylon. For this reason, the nylon-polyester composite fiber can replace the pure nylon staple fiber in various occasions, and its use effect is better than pure nylon under certain production conditions. .
In addition, the development and application of heat resistant fibers can also be applied in thermal bonding processes. For nylon 66, there are outstanding advantages in normal environment, but its performance changes when changing the environment. For example, in high temperature environment, its strength, toughness and elasticity are seriously lost. In some occasions, it has been unable to use, and developed nylon. 66 heat-resistant fiber, used well in the thermal bonding process of nylon nonwoven fabric. Using nylon 66 fiber with high melting point, high elongation and high strength, it is resistant to high temperature by adding heat-resistant agent, and can maintain good physical properties at 240 Â°C. The selection requirement for the modifier is: under the premise of ensuring high temperature and oxidation resistance, the smaller the effect on the physical index, the better the oxidation resistance, the plasticity and lubricity, and Used on a variety of manufacturing equipment. This kind of heat-resistant non-woven fabric has broad development prospects in high temperature resistant garments and military fields, because high temperature resistant antioxidant fibers have anti-ultraviolet oxidation properties at the same time, such as military tents, the use of such non-woven materials can increase the life of ordinary nylon fibers. Double or double.
2. Needle-punched nylon nonwoven fabric
Because nylon has excellent wear resistance and high strength, and has a high melting point, it is commonly used in carpets. The nylon and polyester are usually combed and then reinforced with two needles, and the final product is used as a carpet or floor covering.
The nylon non-woven fabric is manufactured by needle punching method, and the nylon fiber is required to have good dyeing uniformity. In the production process of nylon fiber, dyeing uniformity is one of the important indexes for judging the quality of the product. It not only affects the first-class product rate of the product, but also directly affects the quality of the subsequent process products. In production practice, uneven dyeing tends to cause transversely striped filaments. There are two types of horizontal ray, one is the chromatic aberration of the same sample in the original color, and the other is the swatch difference when multiple samples are woven together.
Because nylon 6 is relatively good in moisture absorption, it is affected by the environmental temperature and humidity during the production process. If the temperature and humidity are too high or too low, it will affect the dyeing uniformity of the product. The reason is that the nylon fiber has different shrinkage rates under different humidity, and the adsorption rate of the dye is different, thereby producing fabric dyeing stripes. In actual production, it is necessary to comprehensively consider the relationship of various factors in order to produce high-quality products.
In order to improve the dyeing performance of the needle-punched nylon nonwoven fabric, the thorn and the production of nylon 6-color masterbatch are applied to the nylon 6 pre-spinning coloring, which has the advantages of small addition amount, no pollution, good spinnability, etc., and nylon 6 is easy to dye. However, the â€œthree wastesâ€ pollution generated during post-dyeing has attracted increasing attention. The pre-spinning coloring of the masterbatch not only solves the pollution problem. It also makes pre-spinning coloring simple and fast, and also compensates for the color effect that can't be dyed.
With the improvement of people's awareness of environmental pollution control, especially the introduction of environmental laws and regulations, the demand for masterbatch has increased, especially with the further study of masterbatch, the development of new products, and the improvement of chromatography. With the improvement of quality, cost reduction, etc., more and more chemical fiber plants will prefer masterbatch. The pre-spinning coloring process of the masterbatch is not only simple and reliable, but also reduces environmental pollution. It also saves printing and dyeing equipment and multiple heating processes, reduces production costs, and the dyeing uniformity is not affected by fiber structure differences. The method is made into an excellent nylon nonwoven fabric.
3. Spunlace nylon non-woven fabric
Split-type nylon can be made into ultra-fine nylon non-woven fabric under the action of high-pressure spunlace for high-performance wipes and suede. In addition, when a spunlace nonwoven fabric mainly composed of viscose fiber is used as a diaper, adding an appropriate amount of nylon to the viscose fiber can significantly increase the strength of the diaper.
Nylon and polypropylene composite microfibers can also be selected as raw materials, and the non-woven fabric is made by hydroentanglement. The composite microfiber has a clear cross section and can be dyed under normal temperature and pressure, and the fabric has good comfort. The fineness of the composite fiber monofilament can improve the hand and the performance. In recent years, China has formed a research and development fever of fine denier and ultrafine denier filaments. The production of ultrafine fibers by conventional spinning method is easy to produce wool, and the number of orifices cannot be greatly increased due to the limited diameter of the spinneret surface, so the fineness of the monofilament is also greatly limited, and the nylon/polypropylene composite is super. The fine fiber is a composite spinning technology, which obtains a fiber with a conventional fineness (single yarn fineness of about 2 to 3 dtex). After processing into a fabric, the two components are peeled off into a single yarn fineness of less than 0.5 dtex after the dyeing and finishing process. Composite microfiber. The fiber fabric has good hand feeling, can be dyed under normal temperature and pressure, has good wicking, moisture permeable and breathable function, and is suitable for making high-grade sportswear, T-shirt, underwear, denim clothing, etc., and can also be made into high-grade high-performance. Spunlace cloth is widely used in medical and health fields.
The nano far-infrared health-care shaped nylon fiber successfully developed in recent years can also be made into an excellent high-grade spunlace cloth. This is a special surface modification technology to prepare nano-scale new far-infrared radiation materials, and compound them with nylon 6 to prepare shaped far-infrared health care nylon filaments. With the improvement of living standards, people's awareness of health care has been continuously enhanced, and far-infrared health care underwear and cold-proof products have been urgently needed by people. It is one of the effective means for preparing far-infrared fibers by adding a far-infrared radiation material having a function of emitting far-infrared rays to the fibers to impart far-infrared radiation. The spunlace cloth has the functions of heat preservation, bacteriostasis, moisture conduction, blood circulation promotion, immunity enhancement, anti-mite and the like.
4. Nylon composite nonwoven
The UK's Dexter Company has developed a composite material with upper and lower layers. The bottom layer can be made of nylon as a raw material, which is reinforced by watering or needle punching after combing into a net; the upper non-woven fabric is wood pulp fiber or plant. Fibers, such as manila hemp, sisal or jute fibers, are produced by wet or airlaid methods. The two layers of materials are compounded by hydroentanglement, and then the composite material is treated with a silicon finishing agent. Usually, the amount of the finishing agent is 3% to 7% by weight of the composite material, and the finished product can be used as a car interior wall panel. And the decorative material inside the car.
The nylon composite non-woven material can also be produced by using polyester/bromine composite filaments, which are one of the differentiated fibers, which are separated and extruded by a special distribution plate by a two-component high polymer melt. . The use of spinnerets of different cross-sectional shapes can form composite fibers of co-spinning, juxtaposition, sheath core, splits and islands. This process is mainly used to develop microfibers and is an ideal material for the manufacture of artificial suede. It has advantages in wool, imitation silk, imitation leather and imitation peach skin. The fabric has good air permeability, moisture permeability and softness, and is suitable for the lens of the advanced lens, and can be applied to thermal insulation materials, filter materials, ultra-high density waterproof and moisture-proof fabrics. Because of its excellent characteristics and wide application, this kind of products will be widely developed to meet the higher-end clothing requirements of the people and provide rich and abundant fiber raw materials for the military and medical industries.
Foreign superfine fiber has already implemented scale production, system application, and formed a situation with many production methods, products, and applications. For domestic use, composite fiber can be mass-produced and can be developed into a one-stop development. Split-type composite fiber is one of them. The production of polyester/gold composite filaments in China is mainly based on the POY-DTY route. The production of some manufacturers has a certain scale and the product quality is stable.
The polyester/bromine composite filament nonwoven fabric has good drapability and shape retention, and has excellent properties such as fluffiness, softness, comfort, moisture absorption and ventilation. Therefore, the products are widely used: such as peach skin, artificial suede, artificial silk fabric, ultra-high density fabric, high-efficiency clean cloth, high-grade wipe cloth, precision instrument cleaning cloth, thermal insulation material, filter material, waterproof and breathable material.
5. Wet nylon nonwoven fabric
The wet non-woven fabric technology is directly made of nylon staple fiber as a raw material, and is formed into a product by forming a net on a paper machine. The method has the advantages of high production speed, low production cost relative to other non-woven fabrics, and wide application range of raw materials. . In recent years, the use of nylon wet-laid nonwovens has been expanding. At present, one of the uses of nylon in wet-laid nonwovens is to increase the tear strength of the paper, and to add a certain proportion of nylon staple fibers to the wood pulp fibers of the papermaking, the tear resistance and bursting strength of the finished paper are Both the breathability and the number of folds are greatly improved. Although the addition of nylon will reduce the tensile strength of the paper, it can increase the amount of the binder by controlling the amount of nylon, increasing the proportion of wood pulp fibers or increasing the amount of binder in the same proportion of nylon. Broken strength. Another use is to use pure nylon, after the process of beating, evenly forming and drying the fibers, to make a pure nylon wet non-woven fabric. In view of the poor hygroscopicity of nylon, it is easy to form agglomerates in water. Therefore, a certain amount of surfactant is added during the papermaking process to make the fibers disperse well, and at the same time, in order to increase the strength of the web, a suitable bonding medium is added. In this way, the nylon wet-laid nonwoven fabric has a uniform appearance, a compact structure and a high tensile strength. Products can be used in decorative materials, linings, high-grade battery separators and durable non-woven fabrics.
In addition, there are spunbonded nylon nonwoven fabrics and meltblown nylon nonwoven fabrics. Among them, only a few companies in the world can produce nylon spunbond fabrics. China has not yet been able to produce nylon spunbond fabrics. Nowadays, nylon spunbond fabrics produced by foreign companies are mainly used as furniture and bedding wraps, filter materials, protective clothing, medical supplies, adhesive base fabrics, automotive interiors, film reinforcement materials and airbag base fabrics.
The melt-blown nylon nonwoven fabric is sprayed by high-speed high-temperature airflow or other means in the direct web forming process of the polymer, so that the melt stream is extremely stretched to form a very fine short fiber web, and the product has high filtration efficiency. Low resistance and softness. Due to the limitations of production equipment, meltblown nylon nonwovens are not currently available in China, but such products have already appeared in foreign countries. For example, Kuss Filtration of the United States has recently produced nylon 6 meltblown webs. It is made up of three layers of fiber mesh. The thickness and length of nylon in each layer are different. The product is mainly used as fuel filter material.