Flowability

Hausner ratio, shear cell, and dynamic flow energy results on the same PBF powder lot rarely agree exactly. That disagreement is a decision input, not proof that a method or lab got it wrong.

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.

CFD-DEM simulations show triboelectrically charged particles can reverse direction in low-drag duct corner zones during pneumatic conveying, with the delay between feed pulses driving the effect more than pulse length.

LED-based particle image velocimetry (PIV) images the velocity field inside a moving powder bed during blending, adding spatial resolution that static angle of repose, Hausner ratio, and shear cell tests cannot provide. Here is what that resolution can and cannot support for a process decision.

In powder-fed laser cladding, a stable feeder setpoint and an in-spec particle size distribution do not guarantee a stable deposit. Catchment efficiency and stream divergence sit between the feeder and the melt pool, and both can drift independently of the powder's PSD.

Co-processing engineers particle morphology, density, and surface structure into a single composite excipient particle. Flow function and compactibility testing show what that buys formulators on continuous direct compression lines, and where it does not.

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.

Copper reflects most near-infrared laser light and conducts absorbed heat away faster than almost any other engineering metal. GRCop-42's move into commercial powder catalogs shows how feedstock morphology, oxide content, and particle size distribution are being engineered around that problem rather than worked around it.

A Pharmaceutical Research study trained Random Forest and XGBoost classifiers on particle size, shape, surface energy, and silica dry-coating data to predict powder blend flowability category. The accuracy holds up as a screening tool and breaks down in specific, predictable places.

Cold spray coatings form only when particles clear a critical impact velocity, a threshold set by material properties, particle size and morphology, and native oxide condition. This article looks at what powder-side QC can flag before a spray trial, and where it stops short of predicting deposition efficiency.

FDA's proposed hub-and-spoke registration rule treats geographically separate manufacturing units as one establishment. The registration paperwork is new; proving that blend uniformity, granulation endpoints, and moisture behavior actually match between sites is the older, harder problem.