pigment in suspension (yellow)

We split the sample into half to demonstrate a grinding with zirconium oxide and stainless steel (result 2).

For the complete provided sample (~ 60 g), we would recommend using a bowl of 250 ml volume. With Planetary Mill PULVERISETTE 5 classic line and Planetary Mono Mill PULVERISETTE 6, maximum bowls of 500 ml can be used.

Usually we recommend mixing the pigment with the proper amount of sample to achieve motor oil like viscosity (for an optimum grinding result). In this case, the sample is already mixed with the solvent. We mixed the slurry as good as possible before starting the grinding trial.

To avoid overpressure, we ground the sample in steps of 5 minutes, followed by a programmed pausing time of 10 minutes. After several cycles, the outside temperature of the bowl should be checked (remain 20°C below boiling point); grinding time or programmed pausing time might be readjusted afterwards. This counts for all further grinding trials too.

After a total of 15 minutes of grinding, the desired level of fineness is already reached. The grinding process has been aborted at this point: now the sample is d50 < 590 nm and d90 < 1,41 µm.

See particle size distribution after 15 minutes; measured with our Laser Particle Sizer ANALYSETTE 22 NanoTec plus; meas.no 49026 on separate page. Also find the result of the original sample on meas. no. 48999 (d50 < 1,12µm; d90 < 2,17µm).

After totally 15 minutes of grinding, the sample use to show a d50 < 560nm, the d90 use to be < 1,39µm.

See particle size distribution after 15 minutes; measured with our Laser Particle Sizer ANALYSETTE 22 NanoTec plus; meas.no 49028 on separate page.

As previously mentioned, the steel abrasion uses to discolor the sample lightly.