Patents by Inventor Edwin Dowthwaite

Edwin Dowthwaite 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).

  • Paper sizing
    Patent number: 4323425
    Abstract: This invention relates to improved rosin sizes, and to improved methods for preparing sized paper. In one embodiment, sized paper is prepared by adding the improved rosin size and a polyamine retention aid to a pulp slurry before sheet formation, without the use of aluminum sulfate. In another embodiment, paper is surface-sized with the improved rosin size in the absence of both aluminum sulfate and retention aids.
    Type: Grant
    Filed: March 21, 1980
    Date of Patent: April 6, 1982
    Assignee: Tenneco Chemicals, Inc.
    Inventors: Edwin Dowthwaite, Ian R. Hiskens