Patents by Inventor John R. Donaldson

John R. Donaldson 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).

  • Pelletizing polymers
    Patent number: 4923649
    Abstract: A method of pelletizing polymer utilizing a liquid medium characterized in that the liquid medium boils at a temperature greater than the melting temperature of the polymer and is immiscible with the molten polymer so that (1) polymer can be heated in the liquid medium to a temperature that causes particulates to melt, (2) the melted polymer can be allowed to agglomerate and (3) the agglomerated polymer can be cooled in a liquid to form pellets.
    Type: Grant
    Filed: March 6, 1986
    Date of Patent: May 8, 1990
    Assignee: Phillips Petroleum Company
    Inventors: Eric T. Hsieh, Gene H. C. Yeh, John R. Donaldson