Patents by Inventor Willem G. Haanstra

Willem G. Haanstra 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).

  • Process for determining the polymer concentration in a spinning dope solution
    Patent number: 6672164
    Abstract: A process for determining the polymer concentration in a spinning dope solution involves measuring the propagation velocity of ultrasonic sound in the solution. The process prevents fluctuations in the polymer concentration as much as possible, and is therefore highly suitable for application in the production of fibers with consistent properties. An ultrasonic device used in the process is easier to clean, install, and calibrate than other presently commercially available devices.
    Type: Grant
    Filed: December 13, 2001
    Date of Patent: January 6, 2004
    Assignee: Teijin Twaron B.V.
    Inventors: Willem G. Haanstra, Hendrikus J. M. Busschers, Hans Lammers
  • Process for determining the acidity of a washing solution for fibers
    Patent number: 6606901
    Abstract: The invention pertains to a process for determining the acidity of a washing solution for removing adhering acid or base from a fibre. The determination is carried out by using a combination of at least two different analytical methods, at least one of which is selected from the density, conductivity, ultrasonic sound, and refractive index measurements. The determination makes it possible to adjust the acidity of the washing solution in such a way that fibres with a minimum amount of adhering acid or base can be produced.
    Type: Grant
    Filed: March 4, 2002
    Date of Patent: August 19, 2003
    Assignee: Teijin Twaron B.V.
    Inventors: Willem G. Haanstra, Hendrikus J. M. Busschers