Hoppers

Wood powder can bridge because fibrous particles mechanically interlock, because moisture increases [...]

DEM input parameters are fitted to match a bulk observable, not derived from first principles. A parameter set calibrated against an angle of repose test constrains one point in a multi-dimensional parameter space. When the hopper geometry changes, the stress state changes, and unconstrained parameters become the dominant source of prediction error.

Jenike shear cells and ring shear testers measure the same yield locus through different mechanics. Here is how their sample, stress range, and time differences map onto the mass-flow versus funnel-flow hopper design decision, plus a checklist for choosing between them.

Powder spreading in powder bed fusion is a recoater-powder interaction shaped by cohesion, particle size distribution, and particle shape. This article maps streaking, short-feeding, and layer non-uniformity back to their underlying mechanisms and separates powder-driven causes from blade wear and spreading speed.

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.

Vibration can improve powder discharge when it breaks a weak arch or [...]

Powder residence time matters because the sample and the failure often describe [...]

Do not diagnose a feeder as if the hopper sends it one [...]

A powder operating window defines the process conditions in which a [...]

Acoustic emission for flow blockage prediction captures high-frequency stress waves generated by [...]

Powder flowability is not one fixed property. A powder can look free-flowing [...]

FIBC discharge problems are often blamed on the powder being discharged too [...]