CONTINUOUS CELLULOID TWIN SCREW EXTRUSION PROCESS

摘要

The present disclosure relates to a continuous extrusion process for producing a celluloid article including several steps and a celluloid article prepared by the continuous extrusion process.

主权项

1. A continuous extrusion process for producing a celluloid article comprising the steps of:
providing a quantity of nitrocellulose; providing a quantity of camphor; providing an extruder defining a chamber, an opening for receiving materials into said chamber, at least two screws for mixing material in said chamber, and an extrusion die coupled to said chamber for extruding material located in said chamber; said chamber comprising a first zone, a second zone, a third zone and a devolatilization zone; introducing the nitrocellulose into said first zone of said chamber, said first zone being maintained at a temperature between about 5° C. and about 15° C.; dissolving said camphor in a low boiling point solvent and introducing said camphor solution into said first zone or said second zone of said chamber; adding an additional solvent to said first zone or said second zone; transporting the nitrocellulose into said second zone of said chamber; continuously mixing said nitrocellulose, camphor and solvent in the said second zone to form a mixture; transporting said mixture to said third zone of said chamber and further continuously mixing said mixture at a higher rate of mixing and temperature relative to said first zone; transporting said mixture to said devolatilization zone and extracting solvent from the mixture in said devolatilization zone by heating the mixture to above boiling points of said solvents; extruding said mixture through said die to produce a celluloid article; and removing the solvents from said celluloid film.