... polymer aggregate or fiber glass added catechin, photocatalyst, cold catalyst, active carbon, vitamin C, aromatics, anti-sensitive or catalyzer. It's ... , anti-sensitive, vitamin C, aromatics, active carbon, photocatalyst, cold catalyst, nano silver to make HEPA filters. It has the function to purify ... size over 0.3um, which is the ideal air filters. The materials of HEPA can be classified five types: ...