Patents by Inventor John David Hewa

John David Hewa 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).

  • Polyester-polyamide blends with reduced gas permeability and low haze
    Patent number: 6444283
    Abstract: The invention relates to polyester/polyamide blend compositions for forming an article having low haze and reduced gas permeability compared to the polyester alone. More specifically, the invention relates to blends of semi-crystalline polyesters such as PET with low molecular weight polyamides and to the containers and packages for food, beverages, cosmetics, pharmaceuticals and personal care products that can be fabricated from these blends.
    Type: Grant
    Filed: July 31, 2000
    Date of Patent: September 3, 2002
    Assignee: Eastman Chemical Company
    Inventors: Sam Richard Turner, Gary Wayne Connell, Steven Lee Stafford, John David Hewa
  • Polyester and optical brightener blend having improved properties
    Patent number: 5985389
    Abstract: The present invention is a compositional blend having a polyester, an acetaldehyde reduction compound and less than 50 ppm of an optical brightener. The blend has utility for food and beverage molded containers where improved clarity and flavor retention are important without producing a haze. The acetaldehyde reduction compound can be a low molecular weight partially aromatic polyamide, a low molecular weight aliphatic polyamides or polyesteramide. The optical brightener preferably is a bis(benzoxazolyl) stilbene. Articles, and especially beverage containers, produced from the blend have a yellowness, b*, less than about 2.5.
    Type: Grant
    Filed: June 15, 1998
    Date of Patent: November 16, 1999
    Assignee: Eastman Chemical Company
    Inventors: James Samuel Nelson Dalton, Steven Lee Stafford, John David Hewa