Air drag on filaments in the melt blowing process

Measurements are reported for air drag on fine filaments in the melt blowing process. The data are fit well by this relation of the Matsui form: Cf=0.78 (ReD)−0.61. A wide range of conditions were used: filament diameters ranged from 13 to 305 μ, gas velocities ranged from 36 to 300 m/s (18 000 m/min), and fiber Reynolds numbers ranged from 15 to 3000. This is a higher and broader range of conditions than has previously been investigated.