Filter medium for air filter, filter pack, air filter unit, and method for producing filter medium for air filter
US10406471B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 2018 |
| Grant date | Sep 10, 2019 |
| Priority date | — |
| Expiry date | Dec 28, 2038 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB32B2535/00
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A filter medium includes first and second porous films mainly containing fluororesin, and a pre-collection member upstream of the first film. The pre-collection member has a pressure drop when air is passed through at a flow rate of 5.3 cm/s of between 15 Pa and 55 Pa, a collection efficiency of NaCl particles having a particle diameter of 0.3 μm when air containing the particles is passed through at a flow rate of 5.3 cm/s of between 25% and 80%, a thickness of 0.4 mm or less, and a PF value between 7 and 15. A ratio of the PF value of the pre-collection member to the PF value when the first and second films are overlapped, is between 0.20 and 0.45. The filter medium can be in a filter pack or filter unit, and produced by integrating the films and the pre-collection member using heat lamination.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.