Method of deinking recovered paper
US8043473B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 21, 2008 |
| Grant date | Oct 25, 2011 |
| Priority date | — |
| Expiry date | Jun 19, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/64
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The object of the present invention is to provide a process for producing deinked pulp from recovered paper containing stickies while preventing excessive reduction in the size of stickies, lowering the COD of effluents, and producing deinked pulp with a smaller residual ink content.In the ink detachment stage of the process for producing deinked pulp from recovered paper containing stickies, an anhydride of crystalline layered silicate is added, preferably in an amount of 0.1-1.5 weight % of absolute-dry pulp, and a deinking treatment is performed at a pH of 7.0-9.9. In the present invention, the deinking treatment is performed in a weakly alkaline to neutral region which is generally said to be effective in reducing the amount of stickies but less effective in ink detachment and, yet, deinked pulp having a smaller amount of residual ink can be produced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.