Abstract: The present invention provides a continuous process for solid-state expansion of a biopolymer, e.g., polylactic acid, which can be used to manufacture reduced-density thermoplastic materials with improved physical and thermal properties. By incorporating multiple stages of heating into the process as a means to regulate heat flux, unprecedented control of microstructure and crystallinity can be achieved. Thermoplastic sheets with the distinct cellular characteristics imparted by the process disclosed herein were found to be thicker and stronger than materials prepared by conventional processes. Thermoforming sheets with such characteristics enabled the production of light-weight, thermally-stable, compostable products that resist warping, and are thus suitable for a range of industrial applications.

Abstract: The present invention provides a continuous process for solid-state expansion of a biopolymer, e.g., polylactic acid, which can be used to manufacture reduced-density thermoplastic materials with improved physical and thermal properties. By incorporating multiple stages of heating into the process as a means to regulate heat flux, unprecedented control of microstructure and crystallinity can be achieved. Thermoplastic sheets with the distinct cellular characteristics imparted by the process disclosed herein were found to be thicker and stronger than materials prepared by conventional processes. Thermoforming sheets with such characteristics enabled the production of light-weight, thermally-stable, compostable products that resist warping, and are thus suitable for a range of industrial applications.

Abstract: A method for deriving value from a mixed waste feedstock can include receiving a mixed waste feedstock including at least a reduced density biopolymer material and an organic feedstock. At least one of a fluid or a material that releases liquids during degradation is added to the mixed waste feedstock. The reduced density biopolymer material is separated, via density separation, from the mixed waste feedstock. The reduced density biopolymer material has a specific gravity below a specific gravity threshold. The reduced density biopolymer material separated from the mixed waste feedstock as a result of the separating is recovered.