Patents by Inventor Thomas G. Grassl

Thomas G. Grassl 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).

  • Patent number: 7297396
    Abstract: A bond is created during gypsum board cure between a gypsum matrix and a tacky coating applied onto a glass fiber. The tacky coating is comprised of a polymer composed of methacrylic acid and dimethyldiallyammonium chloride. The polymer is dissolved in an acidic aqueous solution and is roller coated onto the glass fibers. The chopped glass fibers may also be placed in such an acidic solution, which is made alkaline by the addition of alkali, thereby precipitating the polymer out of solution as a tacky composition that produces a tacky coating on the glass fibers. The glass fibers with the tacky bond coating are incorporated in an alkaline gypsum slurry to form a gypsum board having a first and second facer sheet. The tacky coating on the glass fibers bonded to the gypsum matrix result in compliant load transfer between the gypsum matrix and the glass fibers, yielding improved flexure strength and nail pullout resistance.
    Type: Grant
    Filed: August 3, 2004
    Date of Patent: November 20, 2007
    Assignee: Johns Manville
    Inventors: Lance Wang, Thomas G. Grassl, Robert David Hamilton
  • Patent number: 7238402
    Abstract: A gypsum board having roughened surface glass fiber reinforcement. The roughened surface of glass fiber is created by incorporating nano or micro particles of colloidal silica or clay or other inorganic particles in a silane based sizing composition. The sizing coating is partially or completely cured and incorporated in gypsum wet mix either as additions of chopped fibers or as placement of roughened surface glass fiber mats at selected locations within a cast gypsum sheet. The roughened surface of glass fiber with nano or micro particles compliantly bonded with silane polymer transfers load from gypsum to glass fibers providing improved strength and flexure resistance of gypsum boards.
    Type: Grant
    Filed: March 10, 2004
    Date of Patent: July 3, 2007
    Assignee: Johns Manville
    Inventors: Timothy G. Swales, Philippe M. Scheerlinck, Thomas G. Grassl