Patent · US Expired

Process for acid sulfite digestion of wood

US4295929A · kind A · utility

8Cited by
2References
13Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 19, 1980
Grant dateOct 20, 1981
Priority date
Expiry dateMar 19, 2000

Classification

  • Technology area (CPC D)Textiles; Paper
  • CPC primaryD21C3/06
  • WIPO fieldTextile and paper machines
  • WIPO sectorMechanical engineering

Abstract

The production of chemical pulp by the acid sulfite digestion process is improved by increasing the ratio by weight of combined SO.sub.2 to wood to a range of from 4 to 12 (based on one part of combined SO.sub.2 to 100 parts of dry wood) and by increasing the minimum average rate of heating to the substantially maximum cooking temperature to 40.degree. C. per hour.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.