Most face masks used today are based on meltblown polypropylene fibers, sandwiched between spunbond nonwoven layers. Their effectiveness at filtering small airborne particles relies on electrostatic surface charges, which attract and capture these particles from the air as it passes through the filter. This electrostatic filtering effect only works when the mask is dry and quickly wears off during use, as humidity in the breath eliminates the electrostatic charge. It is for this reason that spunbond/meltblown/spunbond (SMS) filters are not suitable for continuous wear and should be discarded and replaced frequently.
PROVEIL® is different. An extremely thin layer of nanofibers, with diameters more than ten times smaller than conventional meltblown fibers, provides highly effective mechanical filtration for small airborne particles with very little reduction in efficiency over time. The larger surface area and smaller pore size within the PROVEIL® filter maximizes the likelihood of the particles being stopped by the fibers without relying on electrostatic attraction. This means that PROVEIL® filter performance is maintained over time.