Patents by Inventor Richard D. Ladwig

Richard D. Ladwig 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 wallboard manufacture
    Patent number: 4222984
    Abstract: To calcium lignin sulfonate is added a formulation of ammonium or sodium linear alcohol ether sulfate in a ratio to form an additive to calcined gypsum slurry which will reduce the water requirement and the heat needed to cure the wallboard made from the slurry.
    Type: Grant
    Filed: October 30, 1978
    Date of Patent: September 16, 1980
    Assignee: Combustion Engineering, Inc.
    Inventor: Richard D. Ladwig
  • Automatic calcining kettle
    Patent number: 4188186
    Abstract: A vessel is mounted above a furnace, and is used for retaining gypsum as it is calcined to prepare it for making wallboard or plaster. A feed of crushed gypsum supplies the vessel-kettle regulated by the temperature required to calcine gypsum. Calcined gypsum flows from the kettle while maintaining a predetermined level of gypsum in the kettle.
    Type: Grant
    Filed: June 22, 1978
    Date of Patent: February 12, 1980
    Assignee: Combustion Engineering, Inc.
    Inventor: Richard D. Ladwig