Patents by Inventor Pravin Nayar

Pravin Nayar has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Process for recycling polyester materials
    Patent number: 7192988
    Abstract: 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.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: March 20, 2007
    Assignee: Invista North America S.AR.L.
    Inventors: Brad Lee Smith, Pravin Nayar, Gordon Shaw
  • Process for recycling polyester materials
    Publication number: 20060074136
    Abstract: 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.
    Type: Application
    Filed: September 30, 2004
    Publication date: April 6, 2006
    Inventors: Brad Smith, Pravin Nayar, Gordon Shaw