Method and apparatus for providing security features in paper
US4437935A · kind A · utility
41Cited by
8References
2Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 3, 1981 |
| Grant date | Mar 20, 1984 |
| Priority date | — |
| Expiry date | Jun 3, 2001 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21H21/42
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A security device is integrally combined with the fibres of the paper in a paper-making process. A carrier web of water-dispersible fibres carrying the security element is brought into contact with the paper stock during the paper-making process. The carrier web becomes rapidly dispersed upon contact with the wet stock leaving the security element firmly attached to the paper fibres in the stock. In one embodiment, the security element comprises a plastic diffraction grating structure. In a further embodiment, the carrier web comprises an open porous structure for enhancing intermixing with the paper stock.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.