Impact of Rain Water Damage and Natural Depreciation on Filtering Performance of Electret Polypropylene Fiber

摘要

There are many uncertain factors impacting the filtering performance of electret fiber, such as rain water damage and natural depreciation by incorrect deposit. In this paper, filtering performance of two samples was studied, including the fresh fabric of electret polyprophlene fiber and depreciated samples after rain water damage or natural depreciation. The results show that both rain water damage and natural depreciation can significantly reduce the filtering performance of the samples. As to the challenge of multidisperse ambient aerosol, filtering efficiencies of the depreciated samples decrease from 0 to 16 percents, comparing to the corresponding fresh sample. Additionally, natural depreciation after three-year open deposit leads to the decrease of the filtering efficiency of the tested sample by 7.3 percents. The decline of filtering performance can be attributed to the fact that the electrostatic field in the electret polyprophlene fabric has been weaken.