With the intensification of energy and resource crises, consumers’ consumption of fiber materials is also rapidly increasing. Natural fiber is often constrained by land. Synthetic fibers must rely on exhausted oil, natural gas, and other mineral resources. With the consumer demand for fiber materials, the textile industry is constantly looking for new sources of fiber. The use of natural polymer materials such as cellulose, chitosan, starch, algae, and protein to develop regenerated fibers can not only save fiber material resources, but also because these materials themselves are biomass materials that can be naturally degraded and will not harm people and the environment. With adverse effects, the development of recycled fibers will be one of the important ways to produce new fibers.

Lyocell/Tcencel Fiber

Lyocell fiber is a generic name determined by the International Synthetic Fibers and Synthetic Fibers Standardization Bureau (BISFA) for the production of new fibers by organic solvent spinning. In Britain, the United States and other countries, the registered trademark of the fiber is Tencel, which is commonly known as Tencel in China.

Lyocell fiber is manufactured mainly from natural fast-growing forests or other plants. The wood was first sliced ​​into pieces and steamed and rinsed to obtain a cellulose content of more than 96.5%. High-purity wood pulp with a degree of polymerization higher than 600 was then dissolved in wood pulp using N-methylmorpholine oxide (NMMO) as the solvent, and then dried by wet spinning.

NMMO solvent spinning Lyocell fiber production process is different from the ordinary viscose fiber production process, it does not need to alkalinize, aging, yellowing and thermal processes. Production of Lyocell fiber using NMMO as a solvent is a new process for producing cellulose fibers without chemical reaction. When NMMO dissolves cellulose fibers, it does not accompany the decomposition of cellulose. It uses NMMO to generate hydrogen bonds with the polyhydroxy groups on cellulose to dissolve cellulose and obtain a viscous spinning solution, which is then prepared by dry jet wet spinning. Cellulose fiber. At the same time, the precipitates in the coagulation bath and the cleansing bath are recycled and used for recycling. The entire production system forms a closed-loop recycling and recycling system. There is no waste discharge, no pollution to the environment, and no impact on human health. Moreover, the spinning speed is quite high and the production efficiency is high. The solvent is required to be packaged from the pulp into the fiber for 8 hours, while the viscose fiber production generally requires 24 hours, low energy consumption, and high work efficiency. This is a veritable green process.

The raw material of Lyocell fiber is natural cellulose, which has the characteristics of natural cellulose fiber and synthetic fiber after solvent spinning. With the characteristics of high strength, high humidity, dry and wet strength, the dry strength is comparable to that of polyester fiber, and the wet strength is only about 15% lower than the dry strength. Therefore, Lyocell fiber can better withstand the mechanical force and chemical agent treatment, it is not easy to cause fabric damage, and its fabric has good dimensional stability. In addition, Lyocell fiber has natural fiber's own comfort, gloss, dyeing and static electricity, good moisture absorption, its water absorption rate is about 70%, and the water absorption rate of cotton fiber is 50%. The viscose fiber absorbs 90% of the water compared to the benefit. Its boiling water shrinkage rate is only 0.44%, and it also has good wrinkle recovery function and comfortable elasticity. And because it is natural cellulose in nature, it also has good biodegradability.