Apparatus for electrical perforation of webs
US4236062A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1978 |
| Grant date | Nov 25, 1980 |
| Priority date | — |
| Expiry date | Jun 30, 1998 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB26F1/28
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A web is electrically perforated at high hole density by applying alternating-current voltage across an electrode pair facing the web while pressurized gas is supplied to the electrode gap. Voltage amplitude level and gas flow and direction thereof are selected to provide for the striking of multiple arcs per half-cycle, thereby enabling reduction in spacing between adjacent perforations in the web. Perforation practice involving preselection of cigarette filter tipping paper based on chemical composition of the paper is also disclosed as is apparatus for use in implementing the described practices, wherein electrode support members have gas flow conduits formed integrally therewith and wherein webs are taken up by a capstan drive unit resiliently biased into engagement with a web take-up roll.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.