Papermaking process with improved drainage and retention
US5266164A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1992 |
| Grant date | Nov 30, 1993 |
| Priority date | — |
| Expiry date | Nov 13, 2012 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H21/10
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The invention provides a method for improving the retention of mineral fillers and cellulose fibers on a cellulosic fiber sheet. The method comprising the steps of preparing a cellulose pulp slurry; adding before a shearing step an effective amount of a copolymer flocculant to the cellulose pulp slurry, the copolymer flocculant is a high molecular weight cationic copolymer of acrylamide and diallyl dimethyl ammonium chloride, the flocculant copolymer should contain from about 20 to about 60 mole percent diallyl dimethyl ammonium chloride mer units. After a shearing step adding an effective amount of a high molecular weight water-soluble anionic flocculant. A cellulosic fiber sheet is then formed from the cellulose pulp slurry which includes both the copolymer flocculant and anionic flocculant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.