Fabrication of micro‐meltblown filtration media using parallel plate die design

Abstract

ABSTRACTMeltblown fibers are typically produced using a die technology based on the slot concept, an extension of the sheet die technology with a series of holes substituting the center rectangular slot of the sheet die. While this prevalent technology has met with considerable success, an economical, facile design would be desirable. In this study a new parallel plate die concept to fabricate micro‐meltblown fibers that offers simplicity, ease of use, and low cost was examined. The new die concept had parallel plates forming channels for polymer melt to flow through with a set of air holes surrounding them. This die design produced meltblown fibrous media with fibers in the range of 3–10 μm with pore size between 20 and 60 microns. The underlying mechanisms leading to such large fiber size formation and its implication in air filtration performance has been discussed. While conventional meltblown die generates fibers of smaller diameter and webs with higher filtration efficiency than the parallel plate geometry, design modifications could enhance the parallel plate meltblown die performance and make it a viable alternative. These die adaptations that include reducing air flow resistance, increasing the number of air nozzles around the polymer nozzles, recessing the polymer spinnerets above the die face, and having inclined air channels to increase the drag force on the fibers has been discussed. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42998.