Patents by Inventor Christian DE Choudens

Christian DE Choudens 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 preparing chemical paper pulps by cooking, intermediate grinding and a final alkaline peroxide delignification
    Patent number: 4787959
    Abstract: A process of preparing new chemical paper pulps wherein a first cooking stage is effected in the presence of sodium hydroxide and advantageously adjuvants, after which an intermediate grinding is effected and followed by a second cooking stage characterized in that the second cooking stage is performed in the presence of a peroxide alkaline solution containing a peroxide stabilizing agent.
    Type: Grant
    Filed: November 18, 1987
    Date of Patent: November 29, 1988
    Assignee: Atochem
    Inventors: Dominique Lachenal, Christian de Choudens, Pierre Monzie
  • Process for bleaching a mechanical pulp with hydrogen peroxide
    Patent number: 4756798
    Abstract: Mechanical pulp is bleached by a treatment with hydrogen peroxide wherein prior to or simultaneously with said treatment the mechanical pulp is subject to an oxygen pressure.
    Type: Grant
    Filed: April 16, 1987
    Date of Patent: July 12, 1988
    Inventors: Dominique Lachenal, Claude Bourne, Christian de Choudens
  • Method and apparatus for grinding chips into paper pulp
    Patent number: 4088528
    Abstract: In the continuous production of paper pulp from ligno-cellulose raw material, the raw material is subjected to grinding and/or delignification by passing it in the form of small pieces between interpenetrating helicoidal surfaces driven synchronously in rotation inside a casing. The pitch of the helicoidal surfaces is arranged to provide at least one supply zone in which the material is driven downstream by rotation of the surfaces and at least one braking zone in which the material is braked.
    Type: Grant
    Filed: July 27, 1976
    Date of Patent: May 9, 1978
    Inventors: Pierre Berger, Christian DE Choudens, Gerard Lombardo, Pierre Monzie