Patents by Inventor Jan-Erik Hook

Jan-Erik Hook 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).

  • Method for controlling peroxide bleaching in a plurality of bleaching stages
    Patent number: 4878998
    Abstract: Method of peroxide bleaching of mechanical, thermomechanical and chemi-mechanical pulp wherein the peroxide bleaching is controlled by addition of a known amount of bleaching chemicals in the first stage which amount is allowed to react under defined conditions whereafter the brightness of the pulp after this first stage is used for control of a subsequent stage. In the first stage fresh chemicals, chemicals recirculated from a subsequent bleaching stage or a mixture of these is used. Hydrogen peroxide is the preferred bleaching agent but other peroxides can also be used.
    Type: Grant
    Filed: June 20, 1988
    Date of Patent: November 7, 1989
    Assignee: Eka Nobel AB
    Inventors: Jan-Erik Hook, Gorgen Akerlund
  • Method for use in the defibration or refining of lignocellulose-containing fibrous materials
    Patent number: 4311553
    Abstract: A method of producing peroxide bleached pulp. Lignocellulose fiber material is impregnated with an aqueous silicate solution containing a sequestering agent. The impregnated lignocellulose is preheated with saturated steam at a temperature corresponding to the defibrating temperature to precipitate silic acid on and in the fibers. The preheated fiber mass is defibrated between two grinding disc in an atmosphere of saturated steam at a temperature of 100.degree.-170.degree. C. Alkaline peroxide solution free of silicate is introduced into the grinding space.
    Type: Grant
    Filed: January 14, 1980
    Date of Patent: January 19, 1982
    Assignees: Sunds Defibrator AB, Eka AB
    Inventors: Sven G. Akerlund, Jan-Erik Hook