Patents by Inventor Petrus T. A. Klaase

Petrus T. A. Klaase 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).

  • Apparatus for manufacturing an electret filter medium
    Patent number: 4749348
    Abstract: The present invention relates to a continuous method for manufacturing an electret filter medium from dielectric material having an open or porous structure, said method comprising the steps of continuously feeding a web of dielectric material with a substantially closed dielectric foil adjacent to at least one major face thereof into a corona discharge device, reducing the thickness of the web of dielectric material and charging the web of reduced thickness dielectric material by means of a corona discharge and to apparatus for carrying out said method.
    Type: Grant
    Filed: February 3, 1986
    Date of Patent: June 7, 1988
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Petrus T. A. Klaase, Jan van Turnhout
  • Method for manufacturing an electret filter medium
    Patent number: 4588537
    Abstract: The present invention relates to a continuous method for manufacturing an electret filter medium from dielectric material having an open or porous structure, said method comprising the steps of continuously feeding a web of dielectric material with a substantially closed dielectric foil adjacent to at least one major face thereof into a corona discharge device, reducing the thickness of the web of dielectric material and charging the web of reduced thickness dielectric material by means of a corona discharge and to apparatus for carrying out said method.
    Type: Grant
    Filed: February 2, 1984
    Date of Patent: May 13, 1986
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Petrus T. A. Klaase, Jan van Turnhout