The factors that influence pellet quality are: formulation, grinding, conditioning, type of machinery and cooling, but it’s generally agreed that the formulation is by far the most important element affecting the process.
Several studies clearly indicate that pelleted feed improves animal performance and most feed mills are using the pelleting process to reduce pathogens, increase the density of the feed and minimize segregation of ingredients during transport and feeding.
The pellet cooler is used to reduce the high temperature of pellets who just come out from the pellet mill to above room temperature. It plays an important role in large pellet mill plant because the cooling process guarantee pellets production continuously.
Pellet cooling system performance is affected by many variables. The first are variables found in the air being used and include: air temperature, air relative humidity, airflow, the amount of air passing through the cooler.
Press capacity depends substantially on pellet quality (stability according to the PDI, Pellet Durability Index). The durability of pellets shall be determined by tumbling the test sample for 10 seconds at 500 rpm, in a dust-tight enclosure.
Various types of dies are used by the feed manufacturing industry. Die thickness is a factor in the production of high-quality pellets and must be accurately balanced with the formulation and conditioning.