Alternative High-Performance Fibers for Nonwoven HEPA Filter Media

Continual research, development, and advancement in air filtration technology is important to abate the ever increasing health hazards of air pollution and global pandemics. The purpose of this review is to survey, categorize, and compare mechanical and thermal characteristics of fibers to assess their potential applicability in air filter media. The history of high-efficiency particulate air (HEPA) filter development explains how we arrived at the current state of the art nonwoven fibrous borosilicate glass filter paper. This review explores the history and practical uses of particular fiber types and explains fiber production methods in general terms. The thermal and mechanical properties of particular fibers are examined using the codes and standards produced by the American Society of Mechanical Engineers (ASME) to generalize the applicability of fiber categories for HEPA filter units within the nuclear air cleaning industry. This review discusses common measurements for specific strength and tenacity used by the textile and construction industries. Particular fibers are selectively compared for density, tensile strength, tensile stiffness, flexural rigidity, moisture regain, decomposition temperature, and thermal expansion. This review concludes with a subjective assessment of which types of fibers may be appropriate to study for HEPA filtration.