Process for producing very low COD unbleached pulp
US7226525B2 · kind B2 · utility
13Cited by
8References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 30, 2002 |
| Grant date | Jun 5, 2007 |
| Priority date | — |
| Expiry date | Aug 29, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/91
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A pulp product that has a low COD is comprised of an unbleached pulp that is soaked and washed in alkaline water for a sufficient time so that the COD after soaking and washing is less than or equal to 3.0 kg/1000 kg of dry pulp. The pulp is produced by repetitively soaking and washing an unbleached pulp in alkaline water that is never allowed to drop below pH 7.0. The pulp is soaked and washed for a total of at least 400 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.