Meltblown Air-to-Polymer Ratio & Fibre Diameter

The diameter relation is a calibrated power law, not a first-principles attenuation model: real drawdown depends on air velocity and temperature at the nosepiece, polymer melt-flow index, melt temperature and die-to-collector distance, none of which appear here. Fit the reference pair on the line being modelled and the tool will track a change in ratio faithfully; take the reference from a textbook and it will not. Air-to-polymer ratio is computed on mass, which is the comparable basis across lines running different air temperatures - a volumetric ratio quoted at one temperature means something different at another, and comparing two lines on volume is a common way to reach a wrong conclusion. Basis weight assumes all extruded polymer lands on the collector inside the working width, so it ignores edge trim and any shot or fly extracted, both of which are real and both of which make the delivered web lighter than this figure. Blower duty is a first estimate from a specific-energy figure and covers the process air only; die heating, quench and the extruder are additional, but on a meltblown line they are the minority of the load, which is the point worth carrying away.