About Viscose Fibers

Viscose names both a process and the fiber it makes. The process dissolves wood pulp cellulose into a thick golden liquid — the viscose dope — and regenerates it as fiber; the fiber is the regenerated cellulose known in the United States as rayon and in most other markets simply as viscose. Commercial production began in the first years of the twentieth century, making viscose the founding technology of the entire manufactured-fiber industry.

The rayon page on this site treats the fiber family under its American name; this page treats viscose as the process and the international label, because buyers sourcing globally will meet both words on specifications for substantially the same fiber. What follows is how the process works, what the resulting fiber does in fabric, and where its genuine weaknesses — wet strength and production chemistry — have pushed the industry toward modal and lyocell.

The Viscose Process, Step by Step

Purified wood pulp sheets are steeped in caustic soda, which swells the cellulose and converts it to alkali cellulose. The pressed sheets are shredded and aged to bring the cellulose chains to spinning length, then treated with carbon disulphide, which turns the cellulose into cellulose xanthate — orange crumbs that dissolve in dilute caustic soda to form the honey-colored viscose dope that gives the process its name.

After ripening and filtering, the dope is extruded through spinnerets into a bath of sulphuric acid and salts. The acid regenerates the cellulose instantly as continuous filaments, which are stretched, washed, desulphurized, bleached and finished, then wound as filament yarn or cut into staple for spinning. Every quality fault in viscose — uneven dyeing, weak spots, streaks — can usually be traced to control of one of those steps.

Behavior in Fabric

Viscose fabrics drape in soft, fluid folds, absorb moisture readily, feel cool against the skin and take dyes to deep, brilliant shades, which made the fiber the standard silk substitute for dresses, blouses, scarves and linings and a staple of summer clothing. Staple viscose spins into yarns that imitate cotton or blend with it, and high-tenacity viscose once served industrial roles such as tire cord, where modern synthetics have largely replaced it.

Wet, standard viscose loses a large part of its strength and swells, so garments can shrink or distort under careless laundering and many carry gentle-care labels. That single weakness drove the development of the improved family members: modal, engineered for wet strength and stability, and lyocell, made by a different process entirely. Specifying plain viscose for a product that will be washed hard and often repeats a mistake the industry documented generations ago.

Chemistry, Recovery and Progress

The classic viscose plant works with aggressive chemistry, and carbon disulphide emissions and recovery have been the environmental focus of the process for decades. Modern plants recover and recycle a substantial share of their process chemicals and operate under far tighter controls than the early industry, and buyers increasingly ask fiber suppliers for audited chemical management and certified wood sourcing as part of a viscose specification.

The fiber itself remains biodegradable cellulose, and viscose continues to hold a large place in world fiber production because it delivers drape, comfort and color at a price the improved fibers cannot match. The honest sourcing question is never viscose or nothing — it is which member of the viscose family, from which producer, under which chemical controls, for which end use.