Foamed celluloid process using expandable beads

A method of manufacture of a foamed celluloid product having a low density of from about 0.2 to about 0.7 g/cc, the method consisting of:

• a. providing small, generally uniformly shaped pieces of celluloid, not smaller than about 0.1 mm in smallest cross-section;
• b. presoaking the pieces of celluloid in a pressurized reaction vessel, at a temperature of about −50 to about 150 degrees F., in an atmosphere of a physical blowing agent, at a pressure of from about 40 to about 10,000 psi, for a period of from 5 minutes to 72 hours;
• c. heating the presoaked pieces of celluloid to a temperature of from about 80 to about 110 degrees C. to a density of from about 0.3 to about 1.1 g/cc, thereby pre-expanding the presoaked pieces;
• d. transferring the pre-expanded pieces to a mold having the desired shape of the foamed celluloid product, wherein the pieces are heated to from about 200 to about 300 degrees F., for a period of from about 2 to about 60 seconds, during which time the pre-expanded pieces completely foam and expand and take the desired shape at the desired density.