Norcross, Georgia – Micromeritics Instrument Corp, a US-based specialist in material characterisation technology, has developed an optimised and automated solution for testing carbon blacks in accordance with the newly revised US standards.
The Dynamic Void Volume Analyser (DVVA) II has been developed for “safe, clean analysis” in accordance with ASTM D1765-18 classification system for carbon blacks used in rubber products, Micromeritics said in a 21 Jan statement.
Carbon black aggregate structure is one of the properties assessed to provide information for optimisation of the carbon black/polymer ratio, which is considered a key design parameter.
Traditionally, aggregate structure has been analysed via oil absorption testing, which frequently uses a toxic oil, generates significant amounts of hazardous waste, requires a large amount of sample and is not as reproducible as void volume measurement, according to Micromeritics.
The new void volume analyser measures the compressed void volume and apparent density of carbon black powders with precision and accuracy, without requiring chemical agents and using a relatively small amount of sample, the company added.
The process is claimed to be highly reproducible without generating hazardous waste, calculating a range of parameters in under 10 minutes.
In a void volume determination, changes in the apparent volume of a sample are measured as a function of geometric mean pressure by subjecting the sample to progressively higher applied pressures, up to 230 MPa.
The new ASTM classification system includes values of void volume at 50 MPa geometric mean of applied and transmitted pressure for a group of nineteen commercially available reinforcing carbon blacks.
Void volume determinations were performed, in accordance with ASTM D7854-18c, to provide a range of values for each grade.