Patents by Inventor Douglas A. Hofmann

Douglas A. Hofmann 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: 7799713
    Abstract: Glass batch compositions for the formation of high-modulus, and high-strength glass fibers as well as fibers suitable for use as textile and reinforcements are disclosed. Fibers formed of the composition are especially suitable for use in high-strength, low-weight applications such as windmill blades and high strength and modulus applications where strength and stiffness are required in the composite. The glass composition is up to about 70.5 weight % SiO2, about 24.5 weight % Al2O3, about 22 weight % alkaline earth oxides and may include small amounts of alkali metal oxides and ZrO2. Fiberglass-reinforced composite articles such as windmill blades are also disclosed.
    Type: Grant
    Filed: November 4, 2005
    Date of Patent: September 21, 2010
    Assignee: OCV Intellectual Capital, LLC
    Inventors: Douglas A. Hofmann, Peter B. McGinnis
  • Patent number: 7767606
    Abstract: A low viscosity E-glass composition including SiO2 in an amount ranging from 52-54 weight percent, Al2O3 in an amount ranging from 12-14 weight percent, F2 in an amount ranging from 0-1.0 weight percent, Fe2O3 in an amount ranging from 0 to 0.8 weight percent, Na2O in an amount ranging from 0-2.0 weight percent, K2O in an amount ranging from 0-2.0 weight percent, CaO in an amount ranging from 16-23 weight percent, MgO in an amount ranging from 0-3.0 weight percent, Li2O in an amount ranging from 0-3.0, TiO2 in an amount ranging from 0-1.5 weight percent, ZnO in an amount ranging from 0-4.0 weight percent, and B2O3 in an amount ranging from 8.0-10 weight percent is provided. The glass composition has a log 3 viscosity temperature between 1750 and 2150° F. and a ?T temperature greater than 50° F.
    Type: Grant
    Filed: March 15, 2007
    Date of Patent: August 3, 2010
    Assignee: OCV Intellectual Capital, LLC
    Inventors: Peter B. McGinnis, Douglas A. Hofmann
  • Publication number: 20100162772
    Abstract: A method of forming high strength glass fibers in a glass melter substantially free of platinum or other noble metal materials, products made there from and batch compositions suited for use in the method are disclosed. One glass composition for use in the present invention includes 50-75 weight % SiO2, 13-30 weight % Al2O3, 5-20 weight % MgO, 0-10 weight % CaO, 0 to 5 weight % R2O where R2O is the sum of Li2O, Na2O and K2O, has a higher fiberizing temperature, e.g. 2400-2900° F. (1316-1593° C.) and/or a liquidus temperature that is below the fiberizing temperature by as little as 45° F. (25° C.). Another glass composition for use in the method of the present invention is up to about 64-75 weight percent SiO2, 16-24 weight percent Al2O3, 8-12 weight percent MgO and 0.25-3 weight percent R2O, where R2O equals the sum of Li2O, Na2O and K2O, has a fiberizing temperature less than about 2650° F. (1454° C.), and a ?T of at least 80° F. (45° C.).
    Type: Application
    Filed: December 21, 2009
    Publication date: July 1, 2010
    Inventors: Peter B. McGinnis, Douglas Hofmann, David J. Baker, John W. Wingert, Byron Bemis
  • Publication number: 20100069220
    Abstract: A method of forming high strength glass fibers in a refractory-lined glass meter, products made there from and batch compositions suited for use in the method are disclosed. The glass composition for use in the method of the present invention is up to about 64-75 weight percent SiO2, 16-24 weight percent Al2O3, 8-12 weight percent MgO and 0.25-3 weight percent R2O, where R2O equals the sum of Li2O and Na2O, has a fiberizing temperature less than about 2650° F., and a ?T of at least 80° F. By using oxide-based refractory-lined furnaces the cost of production of glass fibers is substantially reduced in comparison with the cost of fibers produced using a platinum-lined melting furnace. High strength composite articles including the high strength glass fibers are also disclosed.
    Type: Application
    Filed: March 13, 2009
    Publication date: March 18, 2010
    Inventors: Peter B. McGinnis, Douglas A. Hofmann
  • Publication number: 20080227615
    Abstract: A low viscosity E-glass composition including SiO2 in an amount ranging from 52-54 weight percent, Al2O3 in an amount ranging from 12-14 weight percent, F2 in an amount ranging from 0-1.0 weight percent, Fe2O3 in an amount ranging from 0 to 0.8 weight percent, Na2O in an amount ranging from 0-2.0 weight percent, K2O in an amount ranging from 0-2.0 weight percent, CaO in an amount ranging from 16-23 weight percent, MgO in an amount ranging from 0-3.0 weight percent, Li2O in an amount ranging from 0-3.0, TiO2 in an amount ranging from 0-1.5 weight percent, ZnO in an amount ranging from 0-4.0 weight percent, and B2O3 in an amount ranging from 8.0-10 weight percent is provided. The glass composition has a log 3 viscosity temperature between 1750 and 2150° F. and a ?T temperature greater than 50° F.
    Type: Application
    Filed: March 15, 2007
    Publication date: September 18, 2008
    Inventors: Peter B. McGinnis, Douglas A. Hofmann
  • Publication number: 20080009403
    Abstract: Glass batch compositions for the formation of high-modulus, and high-strength glass fibers as well as fibers suitable for use as textile and reinforcements are disclosed. Fibers formed of the composition are especially suitable for use in high-strength, low-weight applications such as windmill blades and high strength and modulus applications where strength and stiffness are required in the composite. The glass composition is up to about 70.5 weight % SiO2, about 24.5 weight % Al2O3, about 22 weight % alkaline earth oxides and may include small amounts of alkali metal oxides and ZrO2. Fiberglass-reinforced composite articles such as windmill blades are also disclosed.
    Type: Application
    Filed: November 4, 2005
    Publication date: January 10, 2008
    Inventors: Douglas Hofmann, Peter McGinnis
  • Patent number: 5789329
    Abstract: Boron-free glass fibers suitable for textile and reinforcements are described. The glass fibers have compositions consisting essentially of SiO.sub.2, CaO, Al.sub.2 O.sub.3, and MgO. In a preferred embodiment, the glass contains essentially no fluorine, sulfate, or titania These glass fiber compositions advantageously have broad or large values for delta T (i.e., the difference between the log 3 or forming temperature--the temperature at which the glass has a viscosity of approximately 1000 poise--and the liquidus temperature), e.g., a delta T of at least about 125.degree. F. (52.degree. C.), more preferably of at least about 150.degree. F. (66.degree. C.).
    Type: Grant
    Filed: February 18, 1997
    Date of Patent: August 4, 1998
    Assignee: Owens Corning Fiberglas Technology, Inc.
    Inventors: Walter L. Eastes, Douglas A. Hofmann, John W. Wingert