Investigation of Air Filter Properties of Flash-Spinning Nanofiber Non-Woven Fabric
Shih-Pang Tsai*,, Wei Wu*, Hiroyoshi Sota**, Toshiki Hirogaki***, and Eiichi Aoyama***
*R&D Center, M-TechX Inc.
104 D-egg, 1 Jizodani, Kodo, Kyotanabe-city, Kyoto 610-0332, Japan
**M-TechX Inc., Tokyo, Japan
***Faculty of Science and Engineering, Doshisha University, Kyotanabe, Japan
Using computational fluid dynamics (CFD) technology, a stable manufacturing method for polymeric nanofiber non-woven fabrics based on an improved melt-blowing method and flash spinning is realized to achieve mass productivity. Subsequently, a method to predict filter efficiency using two production methods based on the effects of thickness, filling rate, and fiber diameter on filtration performance is developed to establish a filter design via CFD technology. CFD models featuring uniform fiber diameters are proposed. Next, the pressure loss and flow resistivity are calculated using CFD flow analysis software, as in a filter experiment. The proposed fiber diameter distribution model yields results similar to the experimental value, and the relationship among filling rate, fiber diameter, and flow resistivity is verified. The non-woven filter fabricated in this study demonstrates superior filtration properties, based on the results. Additionally, a method to satisfy both low pressure loss (low flow resistivity) and high filtration efficiency is discussed. Although the pressure loss increases, the filter yields a value below the standard for high-performance face masks, since the fiber diameter is on the nano-order.
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