Regenerated cellulose film recovery process
AssigneeFMC Corporation
InventorsDaniel John Ryan, Edward Andrew Wielicki
Life of this patent
Estimating the term…
Abstract
Waste raw uncoated and/or coated (such as saran, nitrocellulose and vinyl) regenerated cellulose film is treated to recover its plasticizer and cellulose components for recycling in the manufacture of regenerated cellulose film. The platicizer is first recovered from comminuted waste film particles via extraction with water. The moist comminuted film particles are then converted to viscose, from which coating solids, if any, are removed. The viscose is thereafter employed in the manufacture of regenerated cellulose film.
Claims10
A process for recovering regenerated cellulose from plasticized regenerated cellulose film, at least a portion being coated film, which comprises
- (a) comminuting the regenerated cellulose film;
- (b) extracting the plasticizer from the comminuted cellulose film particles by leaching the cellulose with water at a temperature of between 5.degree. C. to 70.degree. C.;
- (c) after leaching, steeping the still moist comminuted cellulose film particles in caustic soda solution to form an alkali cellulose and thereafter xanthating the alkali cellulose with carbon bisulfide to provide a viscose which contains undissolved coating solids;
- and
- (d) separating the coating solids from the viscose thereby obtaining a viscose suitable for use in the manufacture of regenerated cellulose film.
Dependencies are inferred from the claim text.