Processing of Purified Cellulose. The dissolving cellulose pulp sheets are soaked in a caustic alkali solution of 15% to 20% sodium hydroxide, also known as caustic soda, to produce sheets of alkali cellulose. The alkali cellulose sheets are shredded, aged for a few days under closely controlled temperature and humidity, and then bathed in liquid carbon disulfide which transforms the cellulose into cellulose xanthate. Excess carbon disulfide is removed to produce cellulose sodium xanthogenate which is then dissolved in a solution of sodium hydroxide creating a viscous solution.