In the concrete task, only 5 g of leather was to be comminuted though. The production of small chunks of leather through punching is no problem and in addition, guarantees a good profile of the to be examined material. First of all, for the test, leather pieces with approximately 1 cm edge length were cut with scissors. These boundary conditions allow the use of the variable speed rotor mill PULVERISETTE 14. The rotational speed of the rotor was adjusted to16.000 r/min and a 4 mm sieve with a round perforation used.

The dark and extremely thick leather must be pre-comminuted below 1 cm edge length and then slowly dosed. This keeps the thermal burden in acceptable boundaries. The result surprised everyone involved: a very voluminous material evolves. The in this manner won leather sample was used for the determination of the ph-value.

Not quite so difficult was the comminution of thinner, brown leather, similar to leather jackets which consumers are familiar with.

Here the pre-comminution did not have to be as elaborate. In order to keep the thermal strain for this material in bounds, it is also recommended, to use the method of the pre-punched specimens.