Tencel-The English scientific name is Lyocell.
At present, there are two popular lyocell fiber brands on the market: TENCEL produced by Arcadius Company in Britain and LENZING LYOCELL produced by Blue Crystal Company in Austria. Of these two brands, Tencel (brand) occupies a large share in China market and becomes the most famous brand of Lyocell fiber in the world.
PLyocell fiber (that is, soluble fiber) is called the green fiber in the 20th century, and it is a kind of man-made cellulose fiber, which is made from trees in artificially managed forests. Wood pulp is refined by high-tech means, using N- methylmorpholine -N- nutrient (NMMO) as solvent, and produced by advanced "double-ring" solution spinning method, that is, wet-spun regenerated cellulose fiber, which is green and environmentally friendly. It is an environmentally friendly fiber. Waste can be naturally degraded, and 99.5% of amine oxide solvent can be recycled in the production process. "Very low toxicity, no environmental pollution". 1980 was first patented by Akzo-Nobel Company in Germany, and 1989 was officially named by the International Commission on Man-made Fibers and Synthetic Fibers. At present, the world production capacity is about 6.5438+0.2 million tons, which are distributed in the United States, Britain, Austria, Germany, India, South Korea and Taiwan Province Province of China.
Lyocell fiber is used in clothing because of its excellent wearability. It can be spun pure or blended with cotton, hemp, silk, wool, synthetic fiber and viscose fiber to improve the performance of other fibers. The fabric woven with its yarn is glossy, soft and smooth, natural in hand feel, good in drape, good in air permeability and comfortable to wear. Pure lyocell fabric has pearl luster, and its inherent fluidity makes it look light and drape well. Through different textile and knitting processes, pure Lyocell fabrics and blended fabrics with different styles can be woven for high-end jeans, ladies' underwear, fashion, men's high-end shirts, casual wear, casual wear and so on. The newly developed fine denier and ultra-fine denier lyocell fibers make it play a better role in the development of high-grade products. At present, Lyocell products are becoming more and more popular in Japan, Western Europe and the United States, and the sales volume is increasing.
In industrial application, Lyocell fiber has high strength, the dry strength is close to that of polyester, much higher than that of cotton, and the wet strength is almost 90% of the dry strength, which is incomparable to other cellulose fibers. It has been widely used in nonwovens, industrial filter cloth, industrial silk and special paper. Lyocell fiber can be made into nonwovens with various properties by needling, spunlace, wet-laying, dry-laying and thermal bonding, and its properties are better than viscose fiber products. Several European companies are studying the application of lyocell fiber in sewing thread, work clothes, protective clothing, diapers, medical clothing and so on. Japanese paper mills are also developing the application of lyocell fiber in specialty paper.
Lyocell fiber products will produce obvious fibrillation under the friction of mechanical external force in wet state, which shows that fine fibrils and hairiness are separated longitudinally on the yarn surface. The reason of fibrillation is the high axial orientation of Lyocell fibers and the weak transverse bonding force between microfibers. The high expansion of fibers in wet state further weakens this binding force, which makes the fibers fall off under the friction of themselves or metals, and the remaining cortical fibers crack longitudinally, forming long and uneven fibril fluff. Lyocell's fibrillation characteristics make this fiber fabric have two styles. One is to use the fibrillation characteristics of fiber to produce peach skin style products through primary fibrillation, enzyme treatment and secondary fibrillation, and the other is to produce products with smooth surface without secondary fibrillation after enzyme treatment. Lyocell fiber is easy to fibrillate, which brings convenience to the production of non-woven fabrics, filter materials and peach skin style fabrics, but it brings trouble to the production and use of smooth fabrics, such as the control of processing technology, the selection of equipment and additives in production; In the process of use, the fabric is easy to pilling and the color light will also change. In addition, the clothes made of Lyocell fabrics have a strong sense of obsolescence due to the serious fibrillation after repeated daily washing.
Easy fibrillation is one of the characteristics of common lyocell fibers. Fibrillation refers to the splitting of fine microfibers (diameter 1-4um) on the fiber surface. Generally speaking, when fibrillating for the first time, the fibrils produced are relatively large, generally 1mm, or even longer, and can be entangled into a ball. If you don't get rid of it, it will affect your dress and look.
The degree of fibrillation is characterized by the fibrillation index (F.I.), which is generally divided into 0- 10 grades. The higher the grade, the more serious the degree of fibrillation. Generally, when the degree of fibrillation is greater than 2, the appearance of the fabric is ugly.
The higher the temperature, the greater the fibrillation index. Therefore, in order to achieve full fibrillation in actual production, adopting higher temperature can improve production efficiency.
The increase of PH value of aqueous solution is helpful to the swelling and fibrillation of Lyocell fiber. Therefore, in order to improve the efficiency of fibrillation, the PH value of aqueous solution should be increased as much as possible.
Before the treatment time is 90 minutes, the fibrillation index of the fabric has a linear relationship with the treatment time, that is, the fibrillation index increases with the increase of the treatment time, but after 90 minutes, the fibrillation index increases very slowly. Therefore, it can be considered that 90 minutes of fibrillation time should be enough for the fabric under the treatment conditions.
The style of Lyocell fabric is to produce peach skin by itself. Therefore, dyed lyocell fabric needs a secondary fibrillation process to produce secondary fibrils. The fibril produced here should be much thinner and shorter than the fibril produced for the first time, and it is a dense layer of short wool (commonly known as peach skin velvet).
If we fibrillate Lyocell fabric for the first time, and then fully polish it with biological enzyme, then the ideal peach skin can be produced by the second fibrillation, and the peach skin produced at this time will be preserved.
Lyocell fiber is a new generation of regenerated cellulose fiber, which is obtained by dissolving wood pulp in NMMO solvent system and dry spraying wet process, without chemical reaction. First, the patent was obtained by Akzo Nobel Company in Germany on 1978, and then it was successfully commercialized by Courtaulds Company in Britain (later merged into Accordis Company) and Lenzing Company in Austria, and was introduced to markets all over the world. By May 2004, Lanjing had completely acquired the production business of Lyocell fiber (including filament and staple fiber) which once monopolized the global market. Lyocell fiber entered the China market in the mid-1990s, and under the Chinese trade names of Tencel and Wood Pulp Fiber, the R&D and production upsurge of Lyocell fiber series products was triggered in China.
Because the production technology of Lyocell fiber was once completely in the hands of foreign companies, its price has been high. In 2005, China imported 9795t tons of Lyocell fiber, and according to customs statistics, the import unit price was $26 16, which was more than 50% higher than domestic conventional fibers such as cotton, polyester and viscose. In previous years, the import price had reached more than 35,000 yuan/t. Due to cost factors, the price of lyocell fiber follow-up textile products remains high in China.
Since the late 1990s, Donghua University, Shanghai Textile Holding Group and other units have conducted long-term research, and jointly tackled key problems with a German research institute, and achieved success. In February 2006, the first domestic lyocell fiber was successfully produced in Shanghai Leo Development Enterprise Co., Ltd., and the 1 000 t/a production line was officially put into production, breaking the original monopoly pattern of foreign companies. It is estimated that the domestic lyocell fiber output will exceed 10000t/ year around 20 10. It can be predicted that with the success of fiber localization and the continuous expansion of output, the market price of Lyocell fiber in China will continue to fall.
Lyocell fiber has excellent dry and wet strength, the dry strength is close to polyester fiber, and the wet strength is slightly decreased, which is about 85% of the dry strength, so Lyocell fiber has strong mechanical and chemical treatment resistance. The elongation at break of lyocell fiber does not change much in wet state, and the wet elongation is about 65438 07%, which makes its products have good dimensional stability. These advantages make up for the defects of conventional viscose fiber. At the same time, Lyocell fiber has the advantages of low energy consumption and no pollution in the production process, which is incomparable to conventional viscose fiber and is a real green fiber. The global production capacity of lyocell fiber was less than 20,000 t in 1992, and it has been expanded to 15000t/ year. It is estimated that it will reach 450,000 t/a in 20 10, and the market share and influence of lyocell fiber in the regenerated cellulose fiber family will continue to increase. Clothes made of lyocell yarn have the following characteristics.
1. Anti-crease Because wood pulp fiber is not easy to wrinkle, Lyocell, as a representative of wood pulp fiber, has the appearance of ironing without repeated washing.
2. Shrinkage-proof Lyocell has been treated with shrinkage-proof, which eliminates the fear of shrinkage of other cotton fabrics.
3. Soft and smooth Lyocell is softer and smoother after special processing. 4 n) 4。 Moisture absorption Lyocell has good moisture absorption performance, which avoids the shortcoming of slow drying of cotton fabric.
5. Mildew-proof Lyocell itself has unique mildew-proof characteristics and will not cause permanent regret because of your temporary negligence. In addition, Lyocell is also very beneficial to health. Some people abroad have discussed it from the aspects of medicine and exercise physiology, and compared Lyocell with cotton. The changes of ECG show that there are significant differences between them, and Lyocell and parasympathetic nerve have more advantages. Lyocell's comfort also helps the wearer fall asleep. Lyocell is lower than cotton in heart rate, blood pressure and oxygen uptake during and after exercise, indicating that it may reduce the burden on human body during exercise.
Matters needing attention in washing lyocell products
The washing method of Lyocell products is basically the same as that of other products with similar raw materials. If it is a pure Lyocell product, you can rest assured to wash it with a washing machine. If it is mixed with clothes of other raw materials, it must be washed according to the precautions on the label. Similar to jacket clothes, dry cleaning is the best. In order to prevent dyeing, it should be carried out separately from dyed clothes. It is best to use neutral detergent and softener. Most lyocell garments can be machine-washed or dry-cleaned. Lyocell clothes will remain soft after washing. Just gently iron or dry clean at a moderate temperature, and the clothes will return to compliance and softness. If you want to achieve better results, you can wash the net or reverse the bottom and keep it longer. As the clothing manufacturer may process the clothing, please read the maintenance instructions on the clothing label before cleaning.