Particle behavior hub

Understand why powders behave
the way they do

Connect particle characteristics, interactions,
and material state to bulk and process behavior

Particle size, shape, packing, surface interactions, moisture, heat, charge,
and liquid-phase behavior combine to determine how powders perform.
Start with the property you need to understand, or move in from a problem,
process area, or measurement question.

Browse the properties
Start from a powder problem

By property or mechanism icon

By property or mechanism

Start with the particle, bulk, surface, environmental, or liquid-phase behavior you need to understand.

By observed problem icon

By observed problem

Start with the symptom you can observe and work back to the properties and mechanisms that can control it.

By process & equipment icon

By process & equipment

Start from the unit operation and see which powder behaviors become important in that process context.

By test method icon

By test method

Start from the measurement question and connect the result to the property it actually represents.

Powder properties and behavior

Find the property, then understand what controls it

Each page explains what the property or behavior represents, the variables that govern it, how it interacts with other powder characteristics, how it can be measured, and where it matters in processing. Filter by family, or search for a property, mechanism, or familiar technical term.

Showing 6 of 28 properties.

Fine, medium, and coarse particles showing a broad particle size distribution Particle size distribution The balance of fines, coarse particles, and intermediate sizes affects packing, segregation, dust release, dissolution, and process consistency. PSDFinesDistribution Industrial particles with spherical, elongated, angular, and irregular shapes Particle shape and morphology Sphericity, aspect ratio, angularity, surface texture, and particle form influence contact, packing, flow, breakage, and interfacial behavior. ShapeMorphologyTexture Densely packed particles inside a transparent cylindrical test cell Density and packing Particle, bulk, and tapped density describe different aspects of material and bed structure. Packing controls void space, consolidation response, and volumetric process behavior. DensityPackingCompressibility Porous particle showing an interconnected internal pore structure Porosity and surface area Internal pores, accessible pore volume, and specific surface area influence density, adsorption, wetting, dissolution, reaction, and transport. PorositySurface areaPores Faceted crystalline particles in a shallow laboratory dish Crystallinity Crystal order, amorphous content, and polymorphic state can change mechanical, thermal, sorption, dissolution, and stability behavior. CrystallinityAmorphousStructure Intact and fractured granules showing internal breakage surfaces Particle strength and fracture Particle and agglomerate strength determine whether material survives conveying, compaction, impact, and repeated handling or generates fragments and fines. StrengthFractureBreakage Powder flowing freely from a stainless-steel hopper into a receiving vessel Powder flowability Flowability emerges from particle interactions, stress history, air, moisture, geometry, and process conditions rather than from one intrinsic powder number. FlowCohesionConsolidation Fine cohesive powder holding together as a compact clump in a stainless-steel dish Cohesion Attractive forces between particles resist separation and rearrangement, influencing arching, handling, agglomeration, and consolidation. CohesionContactsAttraction Consolidated powder sample undergoing loading in a laboratory shear test cell Shear properties Yield strength, internal friction, and flow function describe how a consolidated powder deforms and fails under shear. ShearStrengthFlow function Packed powder bed in a transparent column representing gas flow through particles Powder permeability The resistance of a powder bed to gas flow controls deaeration, air retention, pressure gradients, and some discharge and densification behavior. AirDeaerationPressure Fine and coarse particle fractions separated across a stainless-steel tray Segregation Differences in size, density, shape, or mobility can separate components during filling, transfer, vibration, mixing, and discharge. DemixingUniformityPercolation Small particles clustered into larger irregular powder agglomerates Agglomeration Particles form larger clusters through cohesive forces, liquid bridges, binders, sintering, or process-driven contacts, changing size and handling behavior. ClusteringGranulationBonding Powder compact under compression in a stainless-steel laboratory press Compaction behavior Particle rearrangement, deformation, fragmentation, and bonding under load determine densification, compact strength, and elastic recovery. CompactionDensificationCompression Fine powder adhering to a vertical stainless-steel process surface Adhesion Particle-to-surface attraction drives sticking, coating, fouling, wall buildup, and product retention on process equipment. StickingFoulingSurfaces Liquid droplet beside fine powder on a metal surface showing interfacial behavior Surface energy Surface free energy influences wetting, adhesion, cohesion, and the tendency of particles or liquids to create and maintain interfaces. Surface energyInterfacesWetting Fine powder attracted to a metal probe and nearby surface by electrostatic effects Electrostatic effects Charge generation, retention, and decay depend on material contacts, humidity, conductivity, and grounding, affecting adhesion, dust, flow, and separation. ChargeTriboelectricConductivity Partially wetted powder showing a clear boundary between dry and liquid-contacted material Wettability The ability of a liquid to spread over and penetrate powder surfaces governs sinking, clumping, air displacement, and the start of dispersion or dissolution. WettingContact anglePenetration Coarse granules surrounded by smaller fragments and fines generated through particle wear Attrition Repeated rubbing, impact, and handling gradually wear particles or granules, shifting particle size distribution and creating fines. AttritionFinesHandling Hard angular granules beside visible wear marks on a stainless-steel surface Abrasion Hard particles or repeated contact can wear particle surfaces, coatings, and process equipment, changing integrity and contamination risk. AbrasionWearCoatings Fine airborne dust released while powder discharges from a stainless-steel transfer point Dustiness A powder's tendency to release airborne particles depends on fines, cohesion, particle strength, handling energy, and environmental conditions. DustFinesRelease Dry loose powder beside darker moisture-affected clumps in a stainless-steel dish Moisture sensitivity Water uptake, sorption state, and humidity history can alter cohesion, surface conductivity, caking, flow, and physical or chemical stability. MoistureHygroscopicityWater activity Powder hardened into cracked cake-like blocks surrounded by loose material Caking Time-dependent particle bonding can convert a free-moving powder into soft lumps or hardened beds through moisture, temperature, pressure, and material transformations. CakingStorageLumps Multiple temperature probes inserted at different positions in a powder bed Thermal properties Heat capacity, conductivity, diffusivity, and bed structure govern temperature response, heat removal, and thermal gradients in powders. Heat transferConductivityTemperature Powder sample with a localized region of chemical discoloration and surface transformation Chemical reactivity Surface area, composition, atmosphere, temperature, moisture, and contamination determine oxidation, decomposition, and other powder reactions. ReactivityOxidationStability Fine particles dispersing through liquid under controlled mechanical mixing Dispersion Deagglomeration and stabilization determine whether particles separate into a liquid and remain distributed rather than reflocculating. DispersionDeagglomerationStability Particles settled at the bottom of a transparent column beneath a clearer liquid phase Sedimentation Particle size, density contrast, liquid properties, and interparticle interactions govern settling, clarification, and suspension stability. SettlingSuspensionStability Thick concentrated slurry folding around a stainless-steel paddle mixer Viscosity Solids loading, particle interactions, and liquid composition determine viscosity, yield behavior, shear response, and processability of concentrated suspensions. RheologyViscositySlurry Undissolved powder particles entering liquid during controlled mixing and dissolution Solubility and dissolution Equilibrium solubility sets how much material can dissolve, while surface area, wetting, mixing, and transport control the rate of dissolution. SolubilityDissolutionKinetics
When behavior becomes a problem

Start with what the powder is doing

If the behavior is already causing a process failure, move into the Troubleshooting Hub. These common routes connect the visible symptom back to the properties and mechanisms worth separating.

Poor flow and discharge icon

Poor flow and discharge

Slow, erratic, or blocked discharge from hoppers, bins, feeders, and process equipment.

Caking and agglomeration icon

Caking and hardened beds

Powder hardens, clumps, or forms persistent agglomerates during storage or processing.

Segregation and blend inconsistency icon

Segregation and blend inconsistency

Fractions separate, causing demixing, composition drift, and inconsistent blends.

Dust and fines release icon

Dust and fines release

Fine particles release during handling, transfer, or processing, or increase through particle damage.

Adhesion, sticking and fouling icon

Adhesion, sticking and fouling

Powder sticks to surfaces, builds up on equipment, or creates persistent deposits and carryover.

Wetting, dispersion and dissolution icon

Wetting, dispersion and dissolution

Powder resists wetting, forms wet lumps, disperses poorly, or dissolves more slowly than required.

View all troubleshooting routes

Technical routes

Connect properties to the rest of PTI

Move from the property view into the sector, process, and measurement context that determines how the behavior becomes relevant in practice.

Industries icon

Industries

See how the same powder property changes in importance across materials, sectors, and production requirements.

Process & equipment icon

Process & equipment

See where material behavior enters storage, transfer, feeding, mixing, forming, deposition, and downstream processing.

Test methods icon

Test methods

Choose measurements by the property or uncertainty that needs to be resolved, not by a test name alone.

Need the measurement, not just the guidance? PowderTechnology.info works closely with Delft Solids Solutions, a contract research organization specializing in the physical behavior of powders and granules. DSS provides contract testing and characterization, with its laboratory working in accordance with ISO 17025. Contact Delft Solids Solutions.

Delft Solids Solutions logo - Partners