Patents by Inventor Stephen W. Alexander

Stephen W. Alexander 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).

  • Two fiber filtration material
    Patent number: 7434698
    Abstract: A filtration material comprising a blend of at least two types of fibers: (a) polypropylene fibers and (b) either acrylic or modacrylic fibers. In a preferred embodiment, the blend contains about 50 weight percent polypropylene fibers and about 50 weight percent modacrylic fibers. In another preferred embodiment, the blend contains about 50 weight percent polypropylene fibers and about 50 weight percent acrylic fibers. The fibers can be blended ranging from 90:10 to 10:90 polypropylene to acrylic or modacrylic. At least one type of fibers includes an extractable agent on the outer surfaces thereof. Performance of the blend is superior to the prior art filtration materials, especially at the preferred compositions.
    Type: Grant
    Filed: December 31, 2003
    Date of Patent: October 14, 2008
    Assignee: Ahlstrom Air Media LLC
    Inventors: Rodney R. Wilkins, K. Dale Montgomery, Stephen W. Alexander, James G. Tuttle, Edwin G. Hoel
  • Three component filtration material
    Patent number: 6808548
    Abstract: A filter material comprising a blend of at least three types of fibers: (a) polypropylene fibers (b) polymethaphenylene isophtalamide fibers and (c) fibers of a third type selected from the group of acrylic and modacrylic. In a preferred embodiment, the blend contains about ten weight percent polymethaphenylene isophtalamide fibers, about 50 weight percent polypropylene fibers and about 40 weight percent modacrylic fibers. Performance of the blend is superior to the prior art filtration materials, especially at the preferred compositions.
    Type: Grant
    Filed: December 31, 2002
    Date of Patent: October 26, 2004
    Assignee: Hollinee Glass Corporation
    Inventors: Rodney R. Wilkins, K. Dale Montgomery, Stephen W. Alexander, James G. Tuttle, Edwin G. Hoel
  • Two fiber filtration material
    Publication number: 20040194625
    Abstract: A filtration material comprising a blend of at least two types of fibers: (a) polypropylene fibers and (b) either acrylic or modacrylic fibers. In a preferred embodiment, the blend contains about 50 weight percent polypropylene fibers and about 50 weight percent modacrylic fibers. In another preferred embodiment, the blend contains about 50 weight percent polypropylene fibers and about 50 weight percent acrylic fibers. The fibers can be blended ranging from 90:10 to 10:90 polypropylene to acrylic or modacrylic. Performance of the blend is superior to the prior art filtration materials, especially at the preferred compositions.
    Type: Application
    Filed: December 31, 2003
    Publication date: October 7, 2004
    Inventors: Rodney R. Wilkins, K. Dale Montgomery, Stephen W. Alexander, James G. Tuttle, Edwin G. Hoel
  • Three component filtration material
    Publication number: 20040123574
    Abstract: A filter material comprising a blend of at least three types of fibers: (a) polypropylene fibers (b) polymethaphenylene isophtalamide fibers and (c) fibers of a third type selected from the group of acrylic and modacrylic. In a preferred embodiment, the blend contains about ten weight percent polymethaphenylene isophtalamide fibers, about 50 weight percent polypropylene fibers and about 40 weight percent modacrylic fibers. Performance of the blend is superior to the prior art filtration materials, especially at the preferred compositions.
    Type: Application
    Filed: December 31, 2002
    Publication date: July 1, 2004
    Inventors: Rodney R. Wilkins, K. Dale Montgomery, Stephen W. Alexander, James G. Tuttle, Edwin G. Hoel