Pulping process with high defiberization chip pretreatment
US7758721B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 19, 2007 |
| Grant date | Jul 20, 2010 |
| Priority date | — |
| Expiry date | Aug 26, 2028 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21D1/30
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A chip pretreatment process which comprises conveying the feed material through a compression screw device having an atmosphere of saturated steam at a pressure above about 5 psig, decompressing and discharging the compressed material from the screw device into a decompression region, feeding the decompressed material from the decompression region into a fiberizing device, such as a low intensity disc refiner, where at least about 30 percent of the fiber bundles and fibers are axially separated, without substantial fibrillation of the fibers. In a more specific form the invention is directed to a process for producing mechanical pulp, including the steps of fiberizing wood chip feed material in a low intensity disc refiner until at least about 30 percent of the fibers are axially separated with less than about 5 percent fibrillation, and subsequently refining the fiberized material in a high intensity disc refiner until at least about 90 percent of the fibers are fibrillated. In another form the invention combines chip fiberizing with chemical treatments, for improving the pulp property versus energy relationships.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.