The Figure shows a schematic illustration of the process in which high-velocity air jets impinge upon the polymer as it emerges from the spinneret. The drag force caused by the air attenuates the fiber rapidly, and reduces its diameter by as much as hundred times from that of the nozzle diameter.
Typical meltblown membranes have fiber sizes ranging from 0.5 to10 microns with an average fiber diameter of 1–2 microns. Meltblown webs are known for their high surface area per unit weight, high insulation value, and high barrier properties.
These properties make them excellent candidates for making high quality filters, surgical drapes and gowns, diaper legcuff, protective apparel where a barrier to fluids and breathability are essential features.
Production of nano-meltblown membranes with an average fiber size in the range of 300–500 nm is possible with improved melt-blowing die designs but at the cost of much lower polymer throughputs and higher air pressures.
Since each spinneret produces a single fiber, the cost of manufacturing commercial nano-meltblown systems with high production rates is prohibitively expensive and impractical.