Analyse von Pulver und Dispersion. Entwicklung von Rezepturen und Pigmenttestung
Flowability of powder
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Causes for distinctions in the flowability of powders
Causes for distinctions while handling powders and bulk solids are often different flow properties. We measure the flow properties of your bulk solids and powders.
Strongly cohesive bulk solids and powders can show differences in handling, transport, conveying, dosage and storage behavior.
This macroscopic powder behavior is dependent on factors such as humidity, particle shape, characteristic of particle surface, particle size distribution, cohesivity and caking behavior.
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Our aim is to characterize all these parameters and work with test methods which can distuingish between the individual application cases.
Test methods
Cohesion test
The auto-adhesive properties of particles and their behavior in agglomeration can be described as their cohesion properties.
Measured Parameter
• Cohesion Index
Fig. 1: Evaluation of collected cohesion measurement data
Caking Test
Caking properties of consolidated powder is measured by Caking Test.
Measured parameter
• Ratio of coulumn and cake hight.
• Energy wich is necessary to destroy consolidated powder cake.
• Stability of powder cake.
Fig. 2: Evaluation of collected cohesion measurement data
Carrs Indices (ASTM D-6393)
The flowability of bulk solids is correlated with the compaction properties using both the Hausner Index and the Carr Index which are found by using standardized tap density and loose bulk density methods. As a result, an evaluation of powder flowability is provided using the FFI Flowability Index table after carrying out experiments. This kind of flowability evaluation is intended for low to medium cohesive powders.
Normen
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EN ISO 787-11 Bestimmung der Stampfdichte
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DIN ISO 697 Bestimmung der Schüttdichte
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ASTM D-6393 Bestimmung der Carr´s Indices
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D-6773: Standard Shear Test Method for Bulk Solids
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ASTM D-7891 - 15 Standard Test Method
