Membrane with perforations, method for producing such a membrane and separating device comprising one or more of such membranes
US4844778A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 21, 1987 |
| Grant date | Jul 4, 1989 |
| Priority date | — |
| Expiry date | Dec 21, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2325/26
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Described, is a membrane and its method of manufacturing which membrane is an electroformed metal foil having areas of high perforation density (higher than 150000/cm.sup.2) and unperforated areas and in particular also unperforated areas having greater thickness than the other areas. The membrane is produced in a process comprising a two step photolithographic procedure in which canals formed in the first photolithographic step are used to ensure good vacuum contact during the second photolitographic step in which the high density pattern is formed in the photolacquer used. The invention also relates to a separation device incorporating one or more membranes according to the invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.