The basic composition of viscose fiber is cellulose (C6H10O5)n o ordinary viscose fiber has a zigzag-shaped core structure in cross section, and the longitudinal direction is straight and grooved. The fiber-rich core-free structure has a circular cross section.
Viscose fiber has good hygroscopicity, and the moisture regain rate is about 13% under normal atmospheric conditions. Significantly swells after moisture absorption, the diameter increases by up to 50%, so the fabric feels hard after the water is launched, and the shrinkage rate is large.
The breaking strength of ordinary viscose fiber is smaller than that of cotton, which is about 1.6~2.7cN/dtex; the elongation at break is larger than that of cotton, which is 16%~22%; the wet strength drops more, about 50% of dry strength, wet stretch The increase is about 50%. The modulus is lower than that of cotton, and it is easily deformed under a small load, and the elastic recovery property is poor, so the fabric is easily elongated and the dimensional stability is poor. The strength of the rich fiber, especially the wet strength, is higher than that of the ordinary adhesive, the elongation at break is small, and the dimensional stability is good. Ordinary viscose has poor wear resistance, while rich fiber has improved.
The chemical composition of viscose fiber is similar to that of cotton, so it is more resistant to alkali than acid, but alkali and acid resistance are worse than cotton. Rich fiber has good alkali and acid resistance. Similarly, the viscose fiber has similar dyeing properties to cotton, and the dyeing chromatogram is complete and the dyeing performance is good. In addition, the thermal properties of viscose fiber are similar to those of cotton, and the density is close to cotton of 1.50~1.52g/cm3.
The hydroxyl group of the macromolecule of cellulose is prone to various chemical reactions. Therefore, the viscose fiber can be modified by grafting or the like to improve the performance of the viscose fiber, and various special-purpose fibers can be produced.
Ordinary viscose fiber has good hygroscopicity, is easy to dye, is not easy to generate static electricity, and has good spinnability. The short fibers can be purely spun or blended with other textile fibers. The fabric is soft, smooth, breathable, comfortable to wear, bright in color after dyeing, and good in color fastness. Suitable for making underwear, outerwear and various decorative items. The filament fabric is light in weight and can be woven into quilt and upholstery fabrics in addition to clothing. Disadvantages of such viscose fibers are poor fastness, low wet modulus, high shrinkage and easy deformation, and poor elasticity and wear resistance.
