Leather sample

In the past, leather samples were often cut to < 4 mm, only. By standard, we only recommend comminuting a sample only as fine as required, not as fine as possible. The leather samples we ground usually fluffed up immensely, even with coarse 4 mm test sieves. With very moistened leather samples, we would expect a clogging of fine perforated sieve cassettes.

With our first trial, we precut the manually into smaller stripes of ~ 30 x 200 mm to pass the standard funnel without problems. If the sample would be wider, the stripes should be convolved for a proper feeding.

The mill was set to its maximum speed of 3.000 rpm. We used a Standard rotor with V-cutting edges and fixed knives made of hardened stainless steel and a sieve cassette with 4,0 mm square perforations. Also, the high-performance cyclone separator and sample exhauster were equipped.

The widest leather fragments were precut longitudinal. The leather sample was fed completely into the mill within 1:45 minutes (105 sec.) and the grinding sound vanished instantly. Only a bit of sample material was left loose inside the grinding chamber. There was no significant clogging of sample on the sieve cassette. Surely much higher amounts of sample could be ground this way, too.

The majority of ground sample was significantly finer than 4 mm would allow to pass. A lot of sample was fluffed up immensely.

Fine grinding to < 1 mm will be performed with result 02.

With this result, we used the precut sample of result 01 for fine grinding. We replaced the sieve cassette against a sieve cassette with 0,75 mm trapezoidal perforations. Typically, a sample which was ground this way should be pass a 1 mm mesh test sieve without problems.

This leather sample was dried enough to be ground with a 0,75 mm perforated test sieve. It took 100 seconds until the complete sample was fed into the mill. The grinding sound was typical and vanished rapidly after the last fragment was fed. In the past, some moisty or oily leather qualities started smearing or clogging inside the grinding chamber.

After 1:50 minutes, the mill was stopped. Only a few of the perforations were clogged, still higher amounts of sample could be ground this way, too. The sample was fluffed up completely.

The grinding chamber was cleaned by vacuuming with a soft brush. Compressed air could also be helpful for rapid cleaning, too.