Electrostatic charges are produced inside a powder at the time of flow. This apparition of electric charges is caused by the triboelectric effect — a charge exchange that occurs at the contact between two solids.
When a powder flows inside a device, such as a silo, mixer, conveyor, and so on, the triboelectric effect occurs at the contact between the grains and the device, and at the contact between the grains. Therefore, properties of the powder as well as the nature of the material used to develop the device are considered to be vital parameters.
GranuCharge instrument accurately and automatically measures the quantity of electrostatic charges produced inside a powder at the time of flow in contact with a chosen material. After the powder sample flows inside a vibrating V-tube, it falls in a Faraday cup coupled to an electrometer. The charge obtained by the powder during the flow within the V-tube is measured by the electrometer. A vibrating or a rotating device is used to continuously feed the V-tube to obtain reproducible results.
- Measurements are quick, simple, and easy to interpret
- Enables the determination of the powder’s initial charge and after a flow
- High repeatability (error approximately 4%) and high precision (accuracy around 0.5 nC)
- Supplied with intuitive software, the charge is determined through the time. Moreover, the software enables the comparison of results, and for post-processing, all data are automatically collected and stored.
- A closed system is provided for safety needs
- Data can be transferred easily and reports can be generated automatically
- Possibility to control the environmental conditions such as humidity, temperature, selected gas, and so on
- Parts can be cleaned easily
- GranuCharge can handle the powders from different dimensions
- Measurement repeatability is increased by the recorded standard operating procedures
- Thanks to its simple design, GranuCharge increases uptime. It is made out of modules and each module can be interchanged to eliminate extensive diagnostics
- The surfaces of the pipes can be exchanged to examine all potential effects of materials for every application
- Principle and design are unique and fully patented
- Change in the charge density is measured through the time
- Classification of powder processability for the galenic formulation
- Provides the possibility to enhance the pneumatic vacuum conveying process, with the choice of optimal tube material combination. Therefore, the agglomeration of particles and sticking of powders on the surface of the pipes could be prevented.
- Offers information about the surface properties of the powder, and therefore the optimization of the recycling process in additive manufacturing becomes accessible.
- Standalone software license; one computer runs the measurement, while the other one analyzes the data for time optimization
- Originally sold with Stainless-Steel 316L pipes, but various materials are also available (HDPE/aluminum/PVC/glass)
- Calibration kit
Powder electric charge measurement principle with Granucharge
Video Credit: Granutools