Security paper comprising localized areas with reduced thickness and opacity, and method for making same
US6402888B1 · kind B1 · utility
19Cited by
5References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 23, 1997 |
| Grant date | Jun 11, 2002 |
| Priority date | — |
| Expiry date | May 23, 2017 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H21/40
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method for making a paper sheet comprising at least one region which is thinner than the rest of the sheet. According to the method, a first paper layer (3) is formed on a wire in a first wet end of a paper-making machine, a second paper layer (5) is formed on a wire in a second wet end of the paper-making machine, one of the two paper layers has a number of localized tinner regions (8) so that the thickness (e2) of said paper layers in said regions is up to 50% less than the thickness (et) of the rest of the sheet, and the two layers are joined together and dried. The resulting paper may be used in banknotes or checks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.