PROCESS FOR RECYCLING POLYESTER MATERIALS

摘要

The present invention is a process for recycling colored polyester. More specifically, colored polyester for recycling is depolymerized by the addition of glycol to form the monomer BHET. The BHET is contacted with activated carbon to remove some colorant. The remaining colorant is extracted with water, alcohol, or glycol to produce white, purified BHET. The white, purified BHET is separated from the extraction solvent (water, alcohol, or glycol) by filtering, decanting, or centrifuging, for example. The purified BHET monomer can be polymerized to polyethylene terephthalate meeting food contact specifications, using known polymerization processes.