Strength, Surface Energy, and Ageing of Meltblown and Electrospun Nylon and Polyurethane (PU) Fabrics Treated by a One Atmosphere Uniform Glow Discharge Plasma (OAUGDP™)

Abstract

The One Atmosphere Uniform Glow Discharge Plasma (OAUGDP™) generates a normal glow electrical discharge at 1 atmosphere in air and other gases. This plasma has been used to treat meltblown and electrospun nylon and polyurethane (PU) fabrics, and has produced an increase in the surface energy/wettability in all cases. Nylon and polyurethane (PU) nanofiber fabrics can be exposed to the OAUGDP™ for up to 10 seconds, long enough to greatly increase their surface energy without significant degradation of strength. After 10 seconds of plasma exposure, the electrospun (but not the meltblown) fabric strength and color degrade to a noticeable extent. It was found that prior to plasma exposure, the strength per unit areal weight of electrospun nanofiber fabrics was (for nylon) up to ten times that of the meltblown material. We also found that the surface energy of meltblown nylon could be increased to 70 dynes cm 1 by 5 seconds of OAUGDP™ exposure, that it was durable at this level for 6 months, and that the surface energy dropped from 70 to 64 dynes cm 1 only after more than 1 year post-exposure. We also report the effects of OAUGDP™ exposure on three surface characteristics of meltblown nylon and PU fabrics: (1) the strength of the fabric as a function of the plasma exposure time; (2) the surface energy of the fabric as a function of the plasma exposure time; and (3) the surface energy/wettability of the fabric as a function of time after exposure (ageing effect). We also describe the treatment of nanofiber fabrics using recent improvements in OAUGDP™ reactor technology