The CVST by HITEC Luxembourg is a void-volume tester, which is derived and further developed from the ASTM standard D6086 “Standard Test Method for Carbon Black – Void Volume (VV)” and compliant to the ASTM standard D7854 “Carbon Black – Void Volume at Mean Pressure”.
The void volume of a carbon black expressed as a function of mean pressure is a carbon black structure property. The greater a carbon black resists compression by having substantial aggregate irregularity and non-sphericity, the greater the compressed volume and void volume. Compressing carbon black powder breaks its agglomerates and aggregates to a similar extent as in the sample preparation for the compressed oil absorption COAN as per ASTM D3493. By measuring the decompression of the powder it is possible to derive a residual void-volume, which reflects well the COAN – this is naturally intuitive as it describes the powder in a similar physical condition (i.e. in uncompressed state after breaking agglomerates/aggregates).
With an exchangeable compression chamber, it is possible to optimize this new method for best testing conditions. Its control software, which is under constant evolution, can further determine other characteristic responses like material friction, work absorbed by compression/decompression, etc. The CVST by HITEC Luxembourg complies with the present requirements of standards on void-volume, but above all it allows to set up test methods and personalize configurations far beyond the requirements of the related ASTM method.
The CVST can be used for the characterization of other powder materials (silica, ceramics, …)
- Two force sensors for applied and transmitted pressure
- Measurement of:
- Void volume vs. applied, transmitted & geometric mean pressure
- Residual void volume reﬂecting COAN structure
- Material friction losses (reflecting NSA/STSA surface)
- Electrical conductivity of carbon black
- Controlled compression and decompression
- Compatible with various porous materials (tested with carbon black, silica, and ceramics)
- Compact design
- Minimal maintenance
- CE marking
- SGS-USTC certified