Methods to enhance brightness of pulp and optimize use of bleaching chemicals
US7351764B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 2004 |
| Grant date | Apr 1, 2008 |
| Priority date | — |
| Expiry date | Mar 31, 2024 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C9/163
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Mechanical or Chemical pulp is treated with about 0.01 weight % to about 5 weight % of a Mixture. The Mixture is water; diethylenetriaminepentakis(methyl)phosphonic acid or its known salts; polyacrylic acid or its known salts; and optionally one or more inert compounds. This Mixture acts to either maintain the brightness level of the pulp at the target level or to increase the brightness level of the pulp. In addition the Mixture allows for maintaining the pulp at the target level of brightness even when the amounts of other ingredients, such as hydrogen peroxide, hydrosulfite, sodium silicate and magnesium, that are typically added to the pulp, are reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.