Methods of manufacture of polylactic acid foams
AssigneeBiopolymer Network Limited
InventorsMichael Ralph Juergen Witt, Samir Shah
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Abstract
Method of forming a composition comprising impregnated polylactic acid (PLA) resin beads, by impregnating PLA resin beads with CO2. The method is carried out by contacting the beads with liquid CO2, and holding the impregnated beads at a temperature and pressure that prevents the beads from foaming while allowing the level of impregnated CO2 to reduce to about 4 to 20 weight % relative to the total weight of the beads and CO2.
Claims25
A method of forming a composition comprising impregnated polylactic acid (PLA) resin beads, the method comprising impregnating PLA resin beads with CO2 by contacting the beads with liquid CO2;
- and holding the impregnated beads at a temperature and pressure that prevents the beads from foaming while allowing the level of impregnated CO2 to reduce to about 4 to 20 weight % relative to the total weight of the beads and CO2.
A method of forming a composition comprising expanded polylactic acid (PLA) resin beads, the method comprising
- (1) providing a composition comprising impregnated PLA beads prepared by a process comprising
- (a) impregnating PLA resin beads with CO2 by contacting the beads with liquid CO2;
- (b) holding the impregnated beads at a temperature and pressure that prevents the beads from foaming while allowing the level of impregnated CO2 to reduce to about 4 to 20 weight % relative to the total weight of the beads and CO2;
- and
- (2) pre-expanding the beads at a pre-expansion temperature.
Dependencies are inferred from the claim text.