Detection of artifacts and agglomerates
Experience with the use of Ultrasonic dispersion for the in-situ measurement of Sequip in collaboration with Hielscher Ultrasonics GmbH
Under certain conditions (e.g. due to high binding forces between the particles) agglomerates can occur during a measurement. In this case, several particles join together and form a particle complex.
These significantly influence the measurement process by:
Change in particle size distribution (as the agglomerates are seen as a single particle)Changes in flow propertiesChange in the normal state of the substance
Consequently, the process now contains many variables that make a reliable evaluation practically impossible.
With Sequip's PAT systems, these changes are seamlessly recorded and reliably evaluated. The direct measurement enables a complementary gain of information for the development of new formulations with regard to the overall morphology.
The measurement is performed in-situ in the laboratory or in-line in the process and in real time depending on the product properties and the dynamic size range.
Now, of course, the question arises how to prevent such a process. The simplest possibility would be to add dispersant. However, this would change the original state of the product and the measurement results would would not reflect the real size distribution. This alternative is therefore unsuitable for process control.
The other and process-independent variant, is the installation of an ultrasonic disperser.
Here a measurement with a Sequip PAT sensor together with an ultrasonic disperser from Hielscher Ultrasonics GmbH performed in a beaker glass.
The disperser emits pulses that drive the agglomerates at the focal point apart by high-frequency waves. As a result, only individual particles reach the focus of the sensor and the true particle sizes are displayed.
Hielscher Ultrasonics GmbH
Ultraschallgerät UP200St + Schallwandler TD mit SonoStep
Multifunctional ultrasonic unit with integrated stirring and pumping function
Powerful 200 watt ultrasonic unit for the laboratory and small-scale production