Filter medium equipped with porous film, method of manufacturing same, filter pack, and filter unit
US9072993B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 2011 |
| Grant date | Jul 7, 2015 |
| Priority date | — |
| Expiry date | Oct 24, 2031 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2275/10
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A filter medium includes a porous film and a support material supporting the porous film. The porous film includes polytetrafluoroethylene, has an average pore diameter of at least 2.5 μm, and has a porosity of at least 95%. A pressure loss is less than 100 Pa when air is passed through the filter medium at a velocity of 5.3 cm/sec. A collection efficiency of NaCl particles is at least 95% when air including NaCl particles with a particle diameter of 0.3 μm is passed through the filter medium at a velocity of 5.3 cm/sec. A PF value is at least 30, where PF={−log [(100−collection efficiency (%))/100]/pressure loss (Pa)}×1000. A dust holding capacity of polyalphaolefin particles held in the filter medium is at least 15 g/m2 when air including polyalphaolefin particles with a count median diameter of 0.25 μm is continuously passed through the filter medium at a velocity of 5.3 cm/sec and pressure loss reaches 300 Pa.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.