Abstract:

Biodegradable polylactic acid (PLA) was chosen as raw material to develop high performance melt-blown filter material and the material was electrified by the external corona discharge. The effect of treatment voltage, time and distance from top electrode to samples on the surface potential, gas-permeability and filtration efficiency of the filter materials were discussed. The change of surface morphology of the material was analyzed by SEM. The SEM images show that the roughness of PLA melt-blown non-woven materials increase after the electret treatment. The results show that the voltage increased, the polarity charging phenomenon appeared. With the increase of electret treatment time and voltage, the surface electrostatic potential increase and then tend to decay with the futher increase of voltage and time. After the electet treatment the air permeability of PLA melt-blown nonwoven materials kept unchanged，while filtration efficiency increased significantly.

Key words: PLA, melt-blown nonwoven material, electret, corona discharge, filtration efficiency