Patents by Inventor Josef Ringel

Josef Ringel 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 the production of cellulose fibers using a two-step pre-treatment
    Patent number: 3998688
    Abstract: A process for the preparation of cellulose fibers from cellulose containing chips wherein the cellulose containing chips are subjected to a chemical process for the purpose of separating the cellulose from lignin and other extraneous chemicals which prior to digestion of the chips subjecting the chips to a two-step pre-treatment by:1. contacting said chips with an aqueous solution of an alkali metal, alkaline earth metal or ammonium sulfite or bi-sulfite metal; and,2. thereafter radiating the so pre-treated chips by contacting them with charged particles.
    Type: Grant
    Filed: September 4, 1974
    Date of Patent: December 21, 1976
    Assignee: VEB Filmfabrik Wolfen-Fotochemisches Kombinat
    Inventors: Klaus Fischer, Josef Ringel