Patents by Inventor Peter I. Chang

Peter I. Chang 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).

  • Patent number: 5762643
    Abstract: A process for the manufacture of a vapor permeable, liquid impermeable composite material comprising a three-dimensional apertured substrate having a vapor permeable, liquid impermeable coating material thereon, the substantially liquid impervious composite material, and an apparatus for making the composite material are disclosed. Successive portions of a continuous sheet of an apertured substrate are passed into contact with a continuous moving perforated member. The coating material is supplied onto the substrate. The coated substrate is subjected to a vacuum which causes the coating material to flow onto the substrate material and in certain embodiments, at least partially into the apertures in the substrate. The vacuum is maintained for a period of time sufficient for the coating material to adhere to the substrate. The coated portions of the substrate are continuously removed from the moving member.
    Type: Grant
    Filed: November 3, 1994
    Date of Patent: June 9, 1998
    Assignee: Tredegar Industries, Inc.
    Inventors: Carl D. Ray, Paul E. Thomas, Robert K. McBride, Peter I. Chang
  • Patent number: 5665824
    Abstract: The present invention relates to degradable thermoplastic compositions comprising at least one polycaprolactone property modifier blended with at least one water soluble polymer and/or at least one alkaline soluble polymer. Articles produced with this composition have a long and useful life under dry or aqueous conditions. When such articles are exposed to a hot aqueous alkaline solution, the composition dissolves and is readily disposed.
    Type: Grant
    Filed: January 31, 1995
    Date of Patent: September 9, 1997
    Assignee: Tredegar Industries, Inc.
    Inventors: Peter I. Chang, Carl D. Ray
  • Patent number: 5258422
    Abstract: The present invention relates to compostable and biodegradable thermoplastic compositions comprising a thermoplastic polymer, a hydrolytically unstable antioxidant, a pro-oxidant, an accelerator, and a property modifier. The hydrolytically unstable antioxidants effectively prevent the thermoplastic polymer from breakdown by oxidative or thermal degradation under dry conditions. Under wet conditions, the hydrolytically unstable antioxidant becomes ineffective and the thermoplastic polymers breakdown to low molecular weight materials.
    Type: Grant
    Filed: May 5, 1992
    Date of Patent: November 2, 1993
    Assignee: Tredegar Industries, Inc.
    Inventors: Peter I. Chang, Carl D. Ray, Alvin W. Gross
  • Patent number: 5254607
    Abstract: Liquid impervious, biodegradable films are disclosed. In particular, the films comprise a blend of an interpenetrated network of destructurized starch with ethylene/acrylic acid copolymers or ethylene/vinyl alcohol copolymers, and an aliphatic polyester such as polycaprolactone. Diapers, sanitary napkins, pantiliners, and the like, containing backsheets prepared from the foregoing materials are also disclosed.
    Type: Grant
    Filed: June 26, 1991
    Date of Patent: October 19, 1993
    Assignee: Tredegar Industries, Inc.
    Inventors: Robert K. McBride, James M. Adams, Peter I. Chang, Carl D. Ray
  • Patent number: 5217803
    Abstract: Liquid impervious, biodegradable films are disclosed. In particular, the films comprise a blend of an interpenetrated network of destucturized starch with ethylene/acrylic acid copolymers or ethylene/vinyl alcohol copolymers, and an aliphatic polyester such as polycaprolactone. Diapers, sanitary napkins, pantiliners, and the like, containing backsheets prepared from the foregoing materials are also disclosed.
    Type: Grant
    Filed: June 26, 1991
    Date of Patent: June 8, 1993
    Assignee: Tredegar Industries, Inc.
    Inventors: Robert K. McBride, James M. Adams, Peter I. Chang, Carl D. Ray