Coating adds oil or oil added to additives e.g. taste, colour or enzymes to a porous pellet. As a rule, the coating process takes a starting point in an extruded pellet, e.g., dog feed, crisps or breakfast cereals. During the process a vacuum is created, air is exhausted and oil is added. The oil is mixed with the material and then a valve is opened so the air flows in and creates atmospheric pressure in the coater. In that way, oil is distributed into the pores.
The advantage of coating is that the customer gets a product that can contain more oil than usual; and it is a product where the oil is more homogeneously distributed in the pellet and not only on the surface.
- Tests with different types of oil, e.g., fish oil and vegetable oil
- Coating as part of feeding tests
- Tests with different flavours for crisps or breakfast cereals
Equipment for coating:
- DTI coater for 15 kg per process
- Andritz coater for 600 kg per process
Pulverization and mixing – Conditioning – Extrusion – Drying – Coating
It is possible to adjust: pressure, vacuum and amount of oil.