wall friction Archives

Screw Feeder Dosing Accuracy and Powder Compressibility: Why the Same Screw Behaves Differently on Similar Products
Gallery
Screw Feeder Dosing Accuracy and Powder Compressibility: Why the Same Screw Behaves Differently on Similar Products

Bulk Solids Characterization, Flowability, Hoppers, Insights, Mixing technology

Screw Feeder Dosing Accuracy and Powder Compressibility: Why the Same Screw Behaves Differently on Similar Products

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.

By Martijn Daalder|2026-07-04T11:38:23+01:004 July 2026|Categories: Bulk Solids Characterization, Flowability, Hoppers, Insights, Mixing technology|Tags: bulk density drift, Carr's Index, Compressibility Index, dosing accuracy, feeder selection, fill factor, flow function, Hausner Ratio, loss-in-weight feeder, powder compressibility, screw feeder, wall friction|0 Comments

Diagnosing and Solving Free-Flowing Powder Arching and Blockage in Hoppers
Gallery
Diagnosing and Solving Free-Flowing Powder Arching and Blockage in Hoppers

Feature Article, Flowability, Hoppers

Diagnosing and Solving Free-Flowing Powder Arching and Blockage in Hoppers

Free-flowing powders can form stable arches and block [...]

By Stephane Sloots|2026-06-27T14:42:25+01:004 April 2026|Categories: Feature Article, Flowability, Hoppers|Tags: critical arching diameter, flow function, free-flowing powder arching, funnel flow, hopper arching, hopper blockage, mass flow, powder flow troubleshooting, shear cell test, time consolidation, unconfined yield strength, wall friction|0 Comments

Wall Friction and Hopper Geometry: Why Some Bins Mass Flow and Others Funnel Flow
Gallery
Wall Friction and Hopper Geometry: Why Some Bins Mass Flow and Others Funnel Flow

Bulk Solids Characterization, Feature Article, Flowability, Hoppers

Wall Friction and Hopper Geometry: Why Some Bins Mass Flow and Others Funnel Flow

Mass flow requires hopper walls that are steep [...]

By Stephane Sloots|2026-06-27T14:42:28+01:0021 March 2026|Categories: Bulk Solids Characterization, Feature Article, Flowability, Hoppers|Tags: bulk solids handling, feeder design, funnel flow, hopper design, hopper geometry, Jenike shear tester, mass flow, outlet sizing, powder flow, rat holing, segregation, silo design, stagnant zones, wall friction, wall friction testing|0 Comments

Why Free-Flowing Powders Still Arch in Hoppers, and How to Diagnose the Real Cause
Gallery
Why Free-Flowing Powders Still Arch in Hoppers, and How to Diagnose the Real Cause

Editors pick, Feature Article, Flowability, Hoppers

Why Free-Flowing Powders Still Arch in Hoppers, and How to Diagnose the Real Cause

A powder can look easy to handle in [...]

By Stephane Sloots|2026-06-27T14:42:30+01:0014 March 2026|Categories: Editors pick, Feature Article, Flowability, Hoppers|Tags: bulk solids handling, critical arching dimension, flow function, free-flowing powders, funnel flow, hopper arching, hopper outlet design, mass flow, powder blockage, powder flow testing, shear cell testing, time consolidation, unconfined yield strength, wall friction|0 Comments

Wall Friction Drift in Hoppers: Why Discharge Degrades Over Time
Gallery
Wall Friction Drift in Hoppers: Why Discharge Degrades Over Time

Bulk Solids Characterization, Caking, Flowability, Hoppers, Insights, Moisture Sensitivity, Shear

Wall Friction Drift in Hoppers: Why Discharge Degrades Over Time

Many hopper issues are boundary-limited. Wall friction drifts [...]

By Martijn Daalder|2026-06-27T14:42:38+01:0031 January 2026|Categories: Bulk Solids Characterization, Caking, Flowability, Hoppers, Insights, Moisture Sensitivity, Shear|Tags: fouling, funnel flow, hopper discharge, humidity control, liners, mass flow, ratholing, shear cell testing, silo flow, wall friction|0 Comments

Hopper Bridging: Why One Hopper Always Bridges First
Gallery
Hopper Bridging: Why One Hopper Always Bridges First

Bulk Solids Characterization, Flowability, Hoppers, Insights, Silo storage

Hopper Bridging: Why One Hopper Always Bridges First

Hopper bridging is rarely random. It points to [...]

By Stephane Sloots|2026-04-18T10:26:02+01:0029 November 2025|Categories: Bulk Solids Characterization, Flowability, Hoppers, Insights, Silo storage|Tags: arching, bulk solids handling, cohesive powders, consolidation stress, flow problems, flowability, funnel flow, hopper bridging, hopper design, hopper outlet diameter, hopper troubleshooting, mass flow, powder flow, powder flow function, powder history, powder testing, ratholing, recycled fines, silo design, wall friction|0 Comments

Angle of Repose Is Not a Flowability Test
Gallery
Angle of Repose Is Not a Flowability Test

Flowability, Insights, Shear

Angle of Repose Is Not a Flowability Test

The angle of repose and flowability are related, [...]

By Stephane Sloots|2026-04-18T10:26:07+01:001 November 2025|Categories: Flowability, Insights, Shear|Tags: angle of repose, Bulk density, flowability, hopper design, powder handling, QA, ring shear, wall friction|0 Comments

Powder Segregation Test: The 20 Minute Bottle Method
Gallery
Powder Segregation Test: The 20 Minute Bottle Method

Bulk Solids Characterization, Flowability, Hoppers, Insights, Particle size distribution, Segregation

Powder Segregation Test: The 20 Minute Bottle Method

Most blend failures start with segregation during transfer. [...]

By Stephane Sloots|2026-04-18T10:27:54+01:004 October 2025|Categories: Bulk Solids Characterization, Flowability, Hoppers, Insights, Particle size distribution, Segregation|Tags: blend uniformity, bottle test, chute design, core sampling, density difference, drop height, fill rate, fines migration, free-fall, hopper design, mass flow, particle size distribution, percolation, potency control, powder segregation test, receiver venting, segregation, trajectory sorting, trickle fill, wall friction|0 Comments