Sugar extrafine

By grinding the sample with a Disk Mill PULVERISETTE 13, sample use to start sticking to the grinding disks and the gap between the movable and the fixed grinding disk will became smaller and smaller. This uses to happen quickly.

After 90 seconds of grinding, all sample use to be ground. Afterwards, about 8 ± 3 g (depending on sample) of residue use to be found mainly loose (or easy to brush off) inside of the grinding chamber.

In this case, sticking sample between the grinding disks needs to be removed with a damped cloth.

After grinding, we determined the amount of desired fraction by sieving an aliquot with our Vibratory Sieve Shaker ANALYSETTE 3 Pro and test sieves of 250 and 500 µm mesh.

Only 6,5 % of sample use to be > 250 µm and < 500 µm as desired. Already 93 % of sample has been ground < 250 µm.

Sample has been ground within 35 seconds. Sieve ring use to be mainly free of sample; no openings are blocked.

Even with a low rotor speed and a coarse sieve ring, sample got ground to fine powder. Already 92,6% of sample use to be ground to < 250 µm. Desired fraction will be found with only 6,2 %.

Probably lowest speed and coarse sieve rings will be able to improve the grinding result (see result 3).

The complete sample amount has been ground within 35 seconds. Afterwards, no openings of the sieve ring are blocked with sample. For a grinding of higher amounts (e.g. 100 g), we recommend using the accessories for grinding large quantities.

With lowest possible speed setting, already 34,1 % of sample use to have the desired particle size. Already 58,4 % of sample use to be < 250 µm.

With the Mortar Grinder PULVERISETTE 2, sample can be ground slowly without bringing much temperature into the sample.

After only 2 minutes of grinding, we sieved an aliquot with our Vibratory Sieve Shaker ANALYSETTE 3 Pro and detected already 26,1 % between 250 and 500 µm. The fraction < 250 µm has already been at 51,3 %. For this, we recommend using a shorter grinding time (see result 5).

With the Mortar Grinder PULVERISETTE 2, sample can be ground slowly without bringing much temperature into the sample.

After only 1 minutes of grinding, we sieved an aliquot with our Vibratory Sieve Shaker ANALYSETTE 3 Pro and detected already 31,6 % between 250 and 500 µm. The fraction < 250 µm has been 38,7 %.

Still 29,7 % of sample use to be > 500 µm and can be used for a further size reduction after separation to optimize the grinding process.

Probably the grinding result can be improved by lifting the scraper a bit, so fine ground particles which tend to stick to the bowl will not be ground any further when they will lift up the pestle.

In this test, the pestle has been lifted a bit above the zero setting and the scraper has been lifted a bit as well. This way, we are hoping that fine ground sample will just pass the pestle without a further comminution.

After 1 minute of grinding, the complete sample has been packed and the fineness has been checked by sieving. We found 30,4 % between 250 and 500 µm; 35 % < 250 µm and 34,6 % > 500 µm.

A maximum output will be achieved by a first separation of desired fraction from the original sample and stepwise grinding of coarse sample analogue result 5. We are guessing that for about 100 g of desired fraction, about 200-250 g of original sugar sample might be needed.