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High yield, low cost cellulosic pulp and hydrated gels therefrom

  • US 4,087,317 A
  • Filed: 08/04/1975
  • Issued: 05/02/1978
  • Est. Priority Date: 08/04/1975
  • Status: Expired due to Term
First Claim
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1. The process of making high yield low cost cellulosic pulp which comprises:

  • (a) mechanically defiberizing lignocellulose by mechanically abrading lignocellulose pieces in an atmosphere of steam at a pressure of from 100 to 170 psi and corresponding temperatures for saturated steam for a time sufficient to reduce the lignocellulose to a fibrous product having a Clark classifier fiber size of less than 10% plus 12 mesh,(b) mixing with the fibrous product from 1% to 20% by weight, dry fiber basis, of lime,(c) adjusting the consistency of the resulting mixture of aqueous lignocellulosic pulp and lime to a consistency of from 10 to 25%,(d) digesting the fiber to pulp form in the presence of the lime to a final pH of from 6 to 8 at steam pressures of from 75 to 125 psi and corresponding temperatures for saturated steam for a digestion period of from 30 to 90 minutes to digestion temperature and from 5 to 60 minutes at said digestion temperature, and(e) mechanically beating the resulting digested fiber in aqueous medium until it is substantially converted to a hydrated cellulosic gel product.

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