Patents by Inventor David Edward Heyer

David Edward Heyer 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).

  • Film bead heating for simultaneous stretching
    Patent number: 5753172
    Abstract: An improved process for simultaneous biaxial stretching of a thermoplastic polymer film having beaded edges in a tenter frame consisting of gripping the beaded edges of the film with tenter clips and increasing the temperature of the beaded edges to within the film orientation temperature range prior to or during simultaneous stretching, and in subsequent stretching or heat-setting steps, by focusing heat on the beaded edges of the film. Thermoplastic films, such as polyethylene terephthalate and polyethylene naphthalate, having a final thickness of from 0.2 to 350 microns after simultaneous stretching can be prepared.
    Type: Grant
    Filed: December 11, 1996
    Date of Patent: May 19, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Albert White Forrest, Jr., David Edward Heyer, Charles Nelson Jolliffe