Rotary airlocks function as pressure boundaries as much as metering devices. The rotor tip clearance governs particle attrition at the nip zone and the rate of fine-particle bypass under differential pressure. As clearance widens through wear, the downstream particle size distribution shifts in a pattern frequently misread as upstream process variation.
The same screw feeder at the same speed can deliver consistently on one powder and drift by several percent on another. The difference lies in compressibility, wall friction, and cohesion, and in how bulk density shifts as the hopper empties.
Temperature shifts surface energy, contact compliance, and residual moisture state in ways that can reverse a powder's ambient flow behavior. This Insight explains the dominant mechanisms across three temperature ranges and what elevated-temperature testing reveals for SLS powder beds, spray dryer outlets, and heated conveying systems.
Vibration can improve powder discharge when it breaks [...]
Powder residence time matters because the sample and [...]
Do not diagnose a feeder as if the [...]
A powder operating window defines the process [...]
Fines in powder behavior matter because fine particles [...]
Coated particle damage can change performance before particle [...]
Powder wettability controls the first contact between powder [...]
