Patent · US Expired

Chemical treatments in bleaching stages which increase pulp brightness

US4238282A · kind A · utility

14Cited by
3References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJul 23, 1979
Grant dateDec 9, 1980
Priority date
Expiry dateJul 23, 1999

Classification

  • Technology area (CPC D)Textiles; Paper
  • CPC primaryD21C9/1042
  • WIPO fieldTextile and paper machines
  • WIPO sectorMechanical engineering

Abstract

A method for increasing the final brightness of pulp contaminated with iron or manganese in a chlorine bleaching process of the type comprising one or more alkaline stages which comprises treating the pulp with at least 0.1 lbs. per ton of a water-soluble chelating agent.

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