Regenerating Cellulose into Fibers. The viscose cellulose solution is aged to allow xanthate groups to revert back to cellulosic hydroxyls and free carbon disulfide, filtered to remove undissolved materials, vacuum treated to remove tiny air bubbles which could weaken the fiber strands, and then forced through spinneret heads (similar to a shower head) to create fine streams of viscose threads in a sulfuric acid bath. The sulfuric acid causes the cellulose xanthogenate to coagulate and bond into filaments of pure regenerated cellulose fibers.