This paper describes the effect of powder compressibility and two process parameters of a dosator nozzle
capsule
filling machine on powder densification during plug formation. One process parameter was the
ratio between the powder bed's depth and the length of the nozzle dosing chamber, hereinafter referred
to as F. The other one was the speed of capsule
filling. This paper demonstrates that powder densification
during the capsule
filling process is a function of the powder compressibility and the above process
parameters (increasing them leads to higher plug density). The Walker model was used to characterize
the compressibility of powders at low compression forces and the obtained compressibility coefficient W
proved to be a good predictor of powder densification during the capsule
filling process.