Musli bars

Original start size of such a candy bar use to be too big for a direct feeding. We ripped the half of the candy bar into smaller pieces with ~ 1,5 cm maximum length. By feeding of the smaller pieces, grinding sound has been smooth which indicates a good grindability (even with the stickiness of the candy bar).

After ~ 15 seconds, all pieces have been fed to the feeding funnel. The rotor and sieve ring use to be mainly free of residues, all sample has been comminuted and will be found in the collecting vessel. For this, a grinding of higher amounts (up to 50 g) is plausible.

We ground the sticky sample at room temperature ( 20°C) a chilling of sample, possibly in a freezer might be beneficial for a grinding with smaller sieve rings.

Just like the first sample, the chocolate covered candy bar use to be too big for a direct feeding. A ripping into pieces or a cutting with a knife is essential for grinding the sample.

Pre cut pieces have been fed within 15 seconds. Even with the soft and sticky chocolate coverage, the sample has been ground without obstacles.

Ground sample can be brushed out of the collecting vessel. Residues on impact rotor or sieve ring use to be minimal. A grinding of higher amounts is possible.

Like the first candy bar, it might be beneficial to chill the sample for a grinding with sieve rings with smaller trapezoidal perforations.

Half of a Nestle musli bar has been cut into small pieces and has been placed into a freezer at -16 °C over night. Next morning, the frozen pieces have been fed to the Variable Speed Rotor Mill PULVERISETTE 14, using a 1,0 mm sieve ring instead of the 2,0 mm sieve ring.

Grinding has been done within 14 seconds. The sample has been ground to a fine, homogenous powder which uses to stick lightly to the collecting pan. Only small amounts of sample use to stick to the rotors ribs. We are guessing that 50 g of sample might be grindable in one batch.

Half of a Chocapic candy bar has been cut into small pieces and has been placed into a freezer at -16 °C over night. Next morning, the frozen pieces have been fed to the Variable Speed Rotor Mill PULVERISETTE 14, using a 1,0 mm sieve ring instead of the 2,0 mm sieve ring.

Grinding has been done within 12 seconds. The sample has been ground to a fine, homogenous powder which uses to stick lightly to the collecting pan. Only small amounts of sample use to stick to the rotors ribs. We are guessing that 50 g of sample might be grindable in one batch.

The sample contains too much sticky substances (chocolate, honey, etc.) for a grinding with a Mortar Grinder PULVERISETTE 2 at room temperature.

We interrupted the grinding process after a total of 3 minutes. Pieces have just become flattened out by the pestle, but they don’t use to fall apart. Probably sample can be ground when the grinding set will be filled with liquid nitrogen (only possible in stainless steel). But maintaining liquid nitrogen will be much more expensive for operating during time.

The compressed pieces have been discharged.

We recommend using a Variable Speed Rotor Mill PULVERISETTE 14 for grinding of such samples.