Method for preparing filtering material
US7387700B2 · kind B2 · utility
5Cited by
4References
3Claims
0Family size
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Key dates
| Filing date | Apr 3, 2002 |
| Grant date | Jun 17, 2008 |
| Priority date | — |
| Expiry date | Dec 22, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S55/05
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method of manufacturing a filter medium that has a PF value that exceeds 32, the PF value calculated from the pressure loss and the collection efficiency of the filter medium according to the following formula:PF=[−log(permeability (%)/100)/(pressure loss (Pa)]×1000[Formula 1]in which permeability (%)=100−collection efficiency (%). In this method, 380 ml or more of a liquid lubricant at 20° C. is added per 1 kg of a PTFE fine powder, this compound is processed into a tape shape and elongated to obtain a PTFE porous film, and an air permeable support member is heat laminated to at least one surface of the PTFE porous film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.