Regenerated fibres are man-made fibres produced by chemically processing naturally occurring polymers, mainly cellulose, and then converting them into a fibre form. They are different from synthetic fibres because their basic raw material comes from natural sources rather than being synthesized entirely from chemicals. Regenerated fibres occupy an important position in the textile industry because they combine some desirable characteristics of natural fibres with the uniformity and versatility of manufactured fibres. The most common raw material for regenerated fibres is cellulose obtained from wood pulp, cotton linters, or other plant materials. Cellulose is first purified and chemically treated to produce a suitable solution or derivative. This material is then forced through very small holes in a spinneret to form continuous filaments. The filaments are solidified by suitable chemical or physical processes, washed, dried, and sometimes stretched or treated further to obtain the desired properties. The fibres may subsequently be cut into staple lengths or retained as continuous filaments. Rayon is the most widely known group of regenerated cellulose fibres. Viscose rayon is produced by treating purified cellulose with chemicals to form a viscous spinning solution. It is then extruded into a coagulating bath where cellulose