Manufacture of paper
US5676796A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 1, 1996 |
| Grant date | Oct 14, 1997 |
| Priority date | — |
| Expiry date | Feb 1, 2016 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H21/10
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Paper is made by forming a thick stock cellulosic suspension, flocculating the thick stock by adding a relatively high molecular weight and relatively low cationic charge density polymer, diluting the flocculated thick stock to form a thin stock and then draining the thin stock to form a sheet. Usually coagulant is added to the thin stock before drainage and best results are achieved by adding coagulant followed by anionic colloidal material such as bentonite. The process can be operated to give good retention and good formation and, if the thick stock is dirty, to minimise pitch problems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.