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Process for producing a pulp suitable for papermaking from nonwood fibrous materials

  • US 6,302,997 B1
  • Filed: 08/30/1999
  • Issued: 10/16/2001
  • Est. Priority Date: 08/30/1999
  • Status: Expired due to Term
First Claim
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1. A process for producing a pulp suitable for making paper from a nonwood fiber source material, the process comprising:

  • (a) providing a nonwood fiber source material;

    (b) extracting the nonwood fiber source material with an alkaline pulping solution at at least about atmospheric pressure;

    (c) reducing the pH of the nonwood fiber source material pH formed in step (b) to an acidic pH with an acid solution;

    (d) treating the nonwood fiber source material having an acidic pH formed in step (c) with ozone; and

    (e) treating the nonwood fiber source material of step (d) with a bleaching solution comprising a bleaching agent different from the ozone of step (d) to form a papermaking pulp, wherein the pulp has a freeness level of at least 400 mL CSF or greater and a brightness level of at least 70% ISO.

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