Abstract:

In order to obtain a low cost and high efficiency filter, the composite filters were prepared from pre-oxidized (PAN) fiber mixed with aramid fiber of different weight percentages. The morphology, fiber entanglement, mechanical properties, air permeability, pore size distribution and filter efficiency were characterized. The results indicated that the length of straight fiber segment can be used to evaluate the degree of fiber entanglement. Adding aramid fiber can enhance fiber entanglement, filter compactness, breaking strength and breaking elongation of the filters, and decreased the pore size. For the particles with diameters above 1.0 μm and 2.5 μm, when the aramid fiber weight percentage is lower than 10%, the filter efficiency of composite filters has no obvious change. However, when the aramid fiber weight percentage is more than 10%, the filter efficiency of composite filters increased significantly with the increase of aramid fiber weight percentage.

Key words: pre-oxidized polyacrylonitrile fiber, aramid fiber, filter efficiency, fiber entanglement, Hough transform