干燥方式对亚微米纤维复合空气过滤材料结构和性能的影响

Influence of Drying Methods on Structure and Performance of Submicron Fiber Composite Air Filter Media

关键词:  空气过滤  亚微米纤维  冷冻干燥  加热干燥  过滤性能

Key Words:air filtration  submicron fiber  freeze drying  heat drying  filtration performance

摘要:以原纤化天丝和玻璃棉这2种亚微米纤维为原料，通过湿法成形的方式将其复合在无纺布基材上制得空气过滤材料（以下简称滤材），探究了冷冻干燥及加热干燥对滤材结构和性能的影响。结果表明，冷冻干燥能较好地保留湿纸幅中亚微米纤维的形态，减少纤维收缩，对原纤化天丝的影响尤为显著；当原纤化天丝与玻璃棉的配比分别为2∶8、4∶6、6∶4、8∶2时，冷冻干燥滤材的过滤效率分别比加热干燥滤材的过滤效率高3.5%、5.5%、9.8%和12.2%，过滤阻力分别比加热干燥滤材低20.4%、28.1%、23.3%和33.2%。可见冷冻干燥可显著提高亚微米纤维复合空气过滤材料的过滤效率，降低其过滤阻力。

Abstract:Two kinds of submicron fibers， fibrillated lyocell fibers and glass wool fibers， were used as raw materials to deposite on PET nonwoven to prepare the composite air filter media by the wet-laid process. The influence of drying methods on structure and performance of submicron fiber composite air filter media was explored. The results showed that freeze drying can retain the morphology of submicron fibers in the wet sheet and reduce the shrinkage； the effect of which on fibrillated lyocell fibers is particularly significant. When the ratio of fibrillated lyocell fibers to glass wool fibers is 2∶8， 4∶6， 6∶4， and 8∶2， respectively， the filtration efficiency of freeze-dried filter media is 3.5%， 5.5%， 9.8%， and 12.2% higher while the filtration resistance is 20.4%， 28.1%， 23.3%， and 33.2% lower than that of the heated counterpart， respectively. It can be seen that freeze drying can significantly improve the filtration efficiency and reduce the filtration resistance of the submicron fiber composite filter media.