Process for making a very low COD unbleached pulp
US7081184B2 · kind B2 · utility
15Cited by
8References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 26, 2002 |
| Grant date | Jul 25, 2006 |
| Priority date | — |
| Expiry date | Feb 27, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/91
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A process for making a pulp product that has a low COD is comprised of soaking and washing pulp in alkaline water for a sufficient time so that the COD after soaking and washing is less than or equal to 2.0 kg/1000 kg of dry pulp. The process includes repetitively soaking and washing an unbleached pulp in alkaline water that is never allowed to drop below pH 7.0. In this process, the pulp is soaked and washed for a total of at least 220 minutes at an elevated temperature to produce the pulp product that has a low COD.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.