Shot and Defect Control in Meltblown Production
topic
Shot formation in meltblown produces polymer droplets or beads from die orifices where extrudate speed exceeds attenuation capacity or polymer degrades to excessive molecular weight reduction, creating large-diameter polymer particles in the web that reduce filtration efficiency by creating oversized pore defects, with die temperature uniformity, polymer throughput control, and resin quality management being the primary shot prevention measures.
Role
Prevents the primary quality defect mode of meltblown filtration media by eliminating shot defects that create localised large pores reducing filtration efficiency below specification, with shot-free production requiring precise control of die temperature uniformity across the full die width, consistent polymer throughput through each die orifice, and melt residence time management that prevents polymer degradation causing viscosity reduction and shot formation.