为制备低成本、高性能耐高温纤维滤料,通过针刺工艺制备了两侧为聚丙烯腈预氧化纤维/芳纶纤维功能层,中间为玻璃纤维基布增强层的复合滤料。采用扫描电子显微镜对复合滤料形貌进行观察并进行了拉伸性能、孔径尺寸、分级过滤性能和动态过滤性能测试。结果表明:随着芳纶纤维质量分数的增加,复合滤料致密性提高,孔径减小,刺针钩刺带动的纤维更多,分担了部分刺针对基布的冲击力,基布损伤减少,复合滤料拉伸断裂强力提高,所制备的复合滤料纵向拉伸断裂强力大于800N,横向拉伸断裂强力大于1000N;随着芳纶纤维质量分数的增加,复合滤料对不同粒径微粒的过滤效率均明显提高,对于粒径≥2.5μm微粒的过滤效率高达99.67%。动态过滤性能测试表明,添加芳纶纤维后,复合滤料稳定阶段清灰周期相对较长,有利于延长其寿命。

In order to obtain low cost,high performances and high temperature resistance filter media,a series of composite filters were prepared through needling,which included two layers of mixture with pre-oxidized PAN fiber and aramid fiber as functional layer,and a enhancement layer between two functional layers based on glass fiber plain woven.Morphological structure of composite was characterized by SEM.Tensile properties,pore size,stage filtration performance and dynamic filtration performance were also characterized.The results indicated that with increasing of weight percentage of aramid fiber,the compactness of composite increased,and the pore size decreased.In addition,the amount of fibers captured by needle barbs increased,and a part of needle impact force was counteracted.As a result,the damage of plain woven decreased and the breaking strength of filters increased.The breaking strength in machine direction and cross direction were greater than 800N and 1000N,respectively.With increasing of the weight percentage of aramid fiber,the filtration efficiency of the composite filters for particles with different size improved significantly.For the particles with a diameter greater than 2.5μm,the filtration efficiency of the filters was high as 99.67%.The dynamic filtration performance test indicated that the filters with aramid fiber had a longer ash cleaning period in stabilization stage,which was beneficial to improving the filter life.