Patents by Inventor Gerard Halna du Fretay

Gerard Halna du Fretay 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).

  • Molding process for the fabrication of hollow shaped articles
    Patent number: 4216253
    Abstract: Hollow shaped articles are extruded, advantageously continuously extruded, from molten thermoplastics by controlled cooling of the molten charge prior to entry into an extrusion die.
    Type: Grant
    Filed: December 7, 1977
    Date of Patent: August 5, 1980
    Assignee: Rhone-Poulenc Industries
    Inventors: Claude Bonnebat, Gerard Halna du Fretay