Method for marking a sheet of paper and sheet with a watermark
US6824647B2 · kind B2 · utility
4Cited by
15References
25Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 12, 2003 |
| Grant date | Nov 30, 2004 |
| Priority date | — |
| Expiry date | May 12, 2023 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H27/02
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method for marking a watermark-type pattern onto at least part of an absorbent paper sheet is described. The method involves stress-deforming the sheet by making it pass between at least one first roll and at least one second roll. A film of additive is applied in unheated manner to at least one of the sheet surfaces during the marking stage, thereby enhancing watermark formation. Additionally described is an absorbent paper sheet including at least one cellulose web ply which is made by the above method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.