Patents by Inventor Douglas A. Leuthold

Douglas A. Leuthold 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).

  • Method of dry separating fibers from paper making waste sludge and fiber product thereof
    Patent number: 5527432
    Abstract: Provided are methods of dry recovering useable fiber from paper making sludge. In the methods, paper making sludge is dewatered and dried. The dewatered and dried sludge is then fiberized using a dry fiberizing machine into a fibrous material consisting of fibers and other material including fiber fines, clay, filler material and the like. The fibers in the fibrous material are then separated out in a sifting process. The separated fibers are then ready for use in paper making without further processing. The fiber fines and filler material separated from the fibers is also collected and can be used as filler material in other composite material applications.
    Type: Grant
    Filed: January 28, 1994
    Date of Patent: June 18, 1996
    Assignee: Advanced Fiber Technology, Inc.
    Inventors: Douglas A. Leuthold, Mark A. Leuthold