... efficiency & light weight 3>Certificate:ISO9001:2008 Air Purifier Cartridge HEPA Filter Production Description:1) Frames: Paper,Aluminum or galvanized frame2 ... 1)air HFPA purifier, air cleaner, vacuum cleaner,etc.2)FFU, electronics, semiconductor, hospital and food industry2)Medical nano silver ... as 0.3 microns.The materials we used to produce HEPA can be classified in five types: PP filter paper, ...