Rayon, also known as viscose fiber, so what is rayon? Why is it also called viscose fiber? Rayon belongs to viscose, also known as rayon (rayon): heavier than real silk, soft, bright color, soft texture, draping straight, smooth, with the appearance of real silk and low price, knitted fabrics feel very soft; viscose fiber is extracted from cellulose materials such as wood and plant stiletto α - cellulose or man-made fiber made from cotton linter by wet spinning.
Viscose fiber belongs to regenerated cellulose fiber. It takes natural cellulose as raw material, through alkalization, aging, sulfonation and other processes to make soluble cellulose sulfonate, and then dissolves in dilute alkali liquor to make viscose, which is made by wet spinning. Ordinary viscose fiber, high wet modulus viscose fiber and high strength viscose fiber can be obtained by using different raw materials and spinning processes. Ordinary viscose fiber has general physical and mechanical properties and chemical properties, and can be divided into cotton type, wool type and filament type, commonly known as rayon, artificial wool and rayon. High wet modulus viscose fiber has high degree of polymerization and wet modulus. Under this condition, the wet elongation per unit density of the fiber is less than 15%. High strength viscose fiber has high and fatigue resistance.
The characteristics of rayon are as follows
The basic composition of viscose fiber is cellulose (C6H10O5) No. the cross-section of viscose fiber is serrated skin core structure, which is straight and straight in longitudinal direction and has groove cross-section. The fiber rich structure has no skin core structure and the cross section is circular. Viscose fiber has good hygroscopicity, and the moisture regain is about 13% under general atmospheric conditions. After moisture absorption, the fabric expands significantly, and the diameter increases by 50%. Therefore, the fabric feels hard and has a large shrinkage after water entry. The breaking strength of viscose fiber is smaller than that of cotton, about 1.6 ~ 2.7cn/dtex; the elongation at break is 16% ~ 22% higher than that of cotton; the wet strength decreases more, about 50% of dry strength, and the wet elongation increases about 50%. Its modulus is lower than that of cotton, it is easy to deform under small load, and its elastic recovery performance is poor, so the fabric is easy to elongate and has poor dimensional stability. The strength, especially wet strength, of rich fiber is higher than that of ordinary viscose, the elongation at break is smaller, and the dimensional stability is good. The wear resistance of ordinary viscose is poor, but the fiber rich is improved. The chemical composition of viscose fiber is similar to that of cotton, so it is more alkali resistant than acid resistant, but the alkali resistance and acid resistance of viscose fiber are worse than that of cotton. Rich fiber has good alkali and acid resistance. Similarly, the dyeing property of viscose fiber is similar to that of cotton, with complete dyeing chromatogram and good dyeing performance. In addition, the thermal properties of viscose fiber are similar to that of cotton, and the density of viscose fiber is 1.50-1.52g/cm3. The hydroxyl groups of cellulose macromolecules are prone to a variety of chemical reactions. Therefore, viscose fibers can be modified by grafting to improve the properties of viscose fibers and produce various fibers for special purposes.
Advantages of rayon:
It has good hygroscopicity, wearability and spinnability. It is often blended and interwoven with cotton, wool or various synthetic fibers, and is used for various clothing and decorative textiles. High strength viscose fiber can also be used in tire cord, conveyor belt and other industrial products. Viscose fiber is a kind of chemical fiber widely used.