Structure Regulation and Properties of Melt-electrospinning Composite Filter Materials

Two kinds of composite filter materials were prepared by regulating the structure of melt-electrospinning polypropylene (PP) webs. The self-designed multi-nozzle melt-electrospinning device was used to produce PP webs which deposited on PP spunbonded nonwoven. Firstly, the composite filter materials with different thickness and ratios of coarse/fine fibers were prepared, and the effect of the thickness and the ratio of coarse/fine fibers on filtration properties were studied. The results showed that the filtration efficiency and pressure drop increased as thickness increased. In addition, compared with the general filters which were composed of coarse or fine fibers, the filters with coarse/fine fibers had low pressure drop under the similar filtration efficiency. In the case of the ratio of coarse/fine fiber about 2:2, this filter achieved optimal performance. When the thickness was 0.42 mm, its filtration efficiency for particles more than or equal to 2.0 mu m could reach more than 95 %. Its pressure drop and air permeability were 18.13 Pa and 54.69 mm/s, respectively, while those of general filter were 38.67 Pa and 10.02 mm/s, respectively. After that, the composite filter materials composed of various angles of oriented webs were produced. The results showed that the filtration efficiency for particles with the size of more than or equal to 2.0 mu m was higher than that of filters composed of one angle of oriented webs. In addition, the lower the orientation was, the lower the pressure drop was.