Patents Assigned to Herbert Graf
  • Process and binder for the manufacture of ceramic shells for use as molds
    Patent number: 5391341
    Abstract: For the manufacture of quickly drying dip coats whose drying time is comparable to the drying time of shells produced on the basis of alcoholic binders, the process uses as a binder for the dip a dispersion of aqueous colloidal silica sol to which synthetic high polymers and/or an emulsion from the group of silicon-organic compounds is formed which after drying is impermeable to water but permeable to water vapor.
    Type: Grant
    Filed: January 17, 1992
    Date of Patent: February 21, 1995
    Assignees: Heinrich Ballewski, Herbert Graf, Wolfgang Grossmann
    Inventors: Heinrich Ballewski, Herbert Graf, Wolfgang Grossmann