Patents by Inventor Donald J. Petersen

Donald J. Petersen 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).

  • Hard-edge wallboard
    Patent number: 4279673
    Abstract: A method of making gypsum wallboard in which a portion of the conventional foamed gypsum slurry for forming the wallboard core is fed through a relatively low speed agitator wherein a defoaming agent is thoroughly admixed therewith, and this portion of the slurry is then disposed along the edge portion of the wallboard being formed, whereby a hard-edge wallboard is produced using less energy than used with prior methods for making a hard-edge wallboard.
    Type: Grant
    Filed: February 11, 1980
    Date of Patent: July 21, 1981
    Assignee: National Gypsum Company
    Inventors: George H. White, Donald J. Petersen