Processes of making paper
US5958188A · kind A · utility
16Cited by
8References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 31, 1997 |
| Grant date | Sep 28, 1999 |
| Priority date | — |
| Expiry date | Dec 31, 2017 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H17/44
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Paper is made by a dual soluble polymer process in which a cellulosic suspension which usually contains alum or cationic coagulant is first flocculated with a high intrinsic viscosity cationic synthetic polymer or cationic starch and, after shearing, the suspension is reflocculated by the addition of a branched anionic water soluble polymer having an intrinsic viscosity above 3 dl/g and tan delta at 0.005 Hz of at least 0.5. The process gives an improved combination of formation, retention and drainage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.