General Introduction
The process of pelleting consists of forcing a soft feed through holes in a metal die plate to form compacted pellets which are then cut into a pre-determined size. The machinery which has been developed for this purpose is now very diverse in design and there is much controversy between different equipment manufacturers as to which type is the most effective. Pelleting is the key to the production of high quality nutritional feeds as they ensure that the feed formulation is in the correct quantities for all that eat them. Each bit of a pellet will have the same designed formulation ensuring all the stock are feed as intended.
Most feed pellet mills now have one or more conditioning units mounted above them where liquids such as water or molasses can be added to improve pelletizing ability. The water sometimes is added in the form of steam which softens the feed and partially gelatinizes the starch content of the ingredients, so as to process firmer (and for aquafeed more stable) pellets.
Working Principle
From the conditioner, the feed falls into the centre of the pelleter itself. In the pelleter two or more rollers and feed ploughs push the material through the holes of the die plate, then form feed pellets.
Usually the die plate itself rotates, and on its outer-side stationary knives cut the pellets to a pre-set length. From there, they are transferred to a cooler/drier to remove the heat which is generated during the pelleting process or is often added during steam conditioning. The moisture content of the pellets also needs to be reduced for proper storage.
Superority
