The first operation is grinding. This is done by a simple machine. It is grinded to a suitable coarseness depending on the type of feed manufactured. First state grinding will reduce the particle size using a 1.0 mm screen on a hammer mill. It is always advisable to remix ingredients manually in the dumping pit before the grinding.
The mixing is important in the feed manufacturing to make sure all the concentrated minerals and vitamins distributed evenly.
The homogenity of the mixer has to be 1:100000. All the liquids like oil are also added at the mixer stage.
Pelletization is done in continuous die presses. The mixed of the raw materials, vitamins and minerals goes through the pellet press whet it is forced though a small opening between 3.2 and 4.8 mm to form pellet.
Maximum compaction should be achieved in the die which would contribute to increased density and therefore sinking rate, water stability and pellet durability.
The skin friction between the feed particles and the walls of the die resist the free flow of feed and thus the particles are compressed against each other inside the die to form pellets.
Foods safety has become a paramount concern for both the consumer and the animal feed industry, in a particular of Salmonella and Campylobacter.
In response to these food safety concern, pelleting temperature are more often being pushed to 90-95 degree C, or higher.
The pellet need to be cooled down to about 25 degree C to harden and stabilize the pellets.
Pellets processing for animal feed
