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US 4,543,364 AGranted
Recovery of polyethylene terephthalate (PET)
AssigneeThe Dow Chemical Company
InventorsRobert J. Nankee, Thomas A. Vivian, Kenneth O. Groves
Life of this patent
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Abstract
A method of reclaiming clear PET resin from bottles and other containers is disclosed. PET resin contaminated with a hot melt type polyethylene copolymer based glue is treated with a chlorinated solvent and optionally subjected to azeotropic drying.
Claims12
A process of recovering clear polyethylene terephthalate (PET) resin in particulate form substantially free from contaminating glue and paper which comprises:
- contacting glue- and paper-contaminated PET particles with a sufficient quantity of a chlorinated solvent to dissolve the glue from the PET and separating the solvent from the particles.
A process of removing paper and glue from scrap particulate polyethylene terephthalate (PET) resin which comprises:
- (a) rinsing the scrap PET with water to thereby form a float of paper and a sink of PET containing less paper and glue;
- (b) separating the PET from the water and float;
- (c) contacting the recovered PET from step (b) with a sufficient amount of a chlorinated solvent maintained at a temperature up to the boiling point of the solvent to dissolve substantially all glue in the PET and floating additional paper;
- (d) separating the PET from the solvent and floated paper;
- and
- (e) removing solvent remaining on the particulate PET by azeotropic distillation employing water.
3 more elements
Dependencies are inferred from the claim text.