Ducks and geese make up the majority of the animals used for feather and down production. About 80 % of down feathers are imported from East Asia. The world's largest producer of goose down is China, followed by Hungary, Ukraine and Poland. Down is a layer of fine feathers which are under the harder outer feathers of the animals. Down is a fine thermal insulator and padding used for example in jackets, bedding, pillows and sleeping bags. To prevent the development of allergies, crushed feathers are checked for harmful substances that may be present in the form of bacteria or fungi due to contamination.
The task was to comminute feathers with the Variable Speed Rotor Mill PULVERISETTE 14 premium line.
The mill ran at the maximum speed of 18,000 rpm, which can be adjusted when the cutting rotor is used. In principle we recommend to use the PULVERISETTE 14 premium line for the comminution of down with a cyclone. During the first test, the High-Performance Cyclone separator with dust exhaust system was equipped with a sample glass with 1 litre capacity. The sample was fed in quickly, a batch of 50 grams of feathers (3-4 cm length) was processed.
After a grinding time of 30 seconds, the 1 litre sample glass was replaced by the 20 litre collection vessel. The bypass of the vacuum was opened to prevent the crushed sample from passing through the cyclone and not being separated in the sample glass. There was little sample residue in the grinding chamber, which was removed with a brush and vacuum. A 20 gram crushed sample was packed.
In the second test with the Variable Speed Rotor Mill PULVERISETTE 14 premium line, the sieve shell holder was equipped with 0.5mm trapezoidal perforated sieve shells. The High-Performance cyclone with exhaust system was equipped with a sample glass of 5 litres capacity. The maximum speed of the cutting rotor 18.000 rpm was set. A batch of 50 grams of feathers (3-4 cm length) was prepared. The sample was fed at a uniformly fast rate. Thus, the entire sample quantity could be comminuted and collected in the 5-litre sample glass. The bypass of the dust exhaust system was open during the grinding process. The throughput was 38 grams of sample material.
Typical residue was found in the opened grinding chamber. The PULVERISETTE 14 premium line was quickly cleaned with brush and vacuum. The fineness of the ground sample differed insignificantly from the previous tests conducted with the 2 mm round perforation sieve shells.
The Variable Speed Rotor Mill PULVERISETTE 14 premium line with the cutting rotor is a suitable instrument for the comminution of down feather.