Solving the curious case of caking
Since the start of November (2021) Delft Solids Solutions is able to test the cause of caking on powders by testing the exposure of powders to a specific temperature (i.e. during various production processes) as well as the RH (relative humidity) to which the powder is exposed.

What is caking?
Caking, or unwanted agglomeration, can present problems in powder processing, capable of making powders that are generally easy to process (free-flowing powders) a challenge. Caking is dependent in understanding the influence of environmental conditions such as humidity, temperature and consolidation are all relevant factors. Changes in temperature can result in condensation. Humid conditions and condensed water can cause partial dissolution of powder particles, forming crystalline bridges between them to create agglomerates. Prolonged consolidation, during which external pressures lead to particles being quite literally forced together, can lead to mechanical aggregation. This is of course dependent of the type of powder being processed as well as its specific production process. During the handling of the powders they are exposed to various temperature and productions conditions. By using the Anton Paar MCR 302 one can assess the RH and the the temperature to optimize the production process. Reversed the MCR 302 can be used  as to assess which current aspect of the  operating process forms the caking, for example during spray drying, mixing, fluidisation, milling of powders etc.

About the Anton Paar M302
The Anton Paar M302 is a rheometer and offers any type or combination of rheological tests, both in rotational and oscillatory mode.  The modularity of the system allows the integration of a wide range of temperature devices and application-specific accessories. The system can be outfitted with various accessories to add to its functionality.

Technical highlights

  • Powerful, synchronous EC motor drive
  • Fully digital instrument employing the latest DSP (Digital Signal Processing) technology
  • High-precision air bearing, including patented normal force sensor
  • TruGap™: Innovative and patented system for measuring the gap
  • TruRate™: Sample-adaptive controller in rotation and step strain
  • TruStrain™: Fast and accurate strain control due to improved real-time position control oscillation (formerly DSO)
  • Intuitive color display

Standards
The Anton Paar 302 works in accordance with the following standards:

– ASTM D4440

– ASTM D4473

– ASTM D5279

– DIN 13343

– DIN 1342 1-3

– DIN 3219

– DIN 51810 Part 1

– DIN 51810 Part 2

– DIN 53019-1

– DIN 53019-2

– DIN 54458

– EN 14770

– EN 3219

– Ph. Eur. 0132

– Ph. Eur. 2.2.10 – Rotating viscometer method

– Ph. Eur. 2.2.8 – Viscosity

– ISO 3219

– ISO 6721-1