Opening of envelope with darkened edges
US4222216A · kind A · utility
0Cited by
9References
14Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 5, 1979 |
| Grant date | Sep 16, 1980 |
| Priority date | — |
| Expiry date | Feb 5, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S83/912
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A process is provided for the opening of envelopes made of cellulosic paper by the action of a chemical degradation agent in the presence of radiant heat in which the radiant heat is generated from a source maintained at a temperature high enough to produce a substantial amount of radiation having a wave length of 2 microns or less and by applying to the edges to be opened a darkening material capable of absorbing a substantial portion of the incident radiant energy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.