Pellet durability is important if the benefits associated with pelleting are to be realized. Feed pellet durability depends upon several factors as follows:
1. Particle Size
In general, smaller mash particle size enhances better pellet quality since the material has a larger surface area that allows heat and moisture from steam to more quickly and thoroughly penetrate the particle. In addition, smaller particles also have more surface area to adhere to and bind to other particles in the pellets.
2. Die Material
It is important to choose the right die material. Pellet dies are usually made from alloy, stainless, or high chrome. Now I would like to focus on alloy dies. Alloy dies are made of medium-grade carbon steel. They are designed for heavily abrasive applications and typically are the most breakage-resistant dies available. In general, alloy dies are less expensive than stainless steel or high chromium dies. In fact, alloy dies can meet your actual pelleting requirements.
3. Moisture Content
The moisture content can also affect pellet durability. Moisture in feed comes from two sources: bound moisture and added moisture. The former is present in the feed’s ingredients and the latter is from water and steam addition. Varying moisture affects the conditioning process and pellet mill operation. Research has shown that there is a high correction between moisture content and pellet durability.
4. Pellet Cooling
Proper pellet cooling depends upon adequate airflow and cooler retention time. Poor cooling reduces pellet durability. Poor pellet cooling in vertical and horizontal coolers is attributed to airflow restrictions and caused by plugged cooler screens, trays or air inlets. Typically, if greater retention time is needed, adding additional height to cooler walls or horizontal sections is done to increase the cooler’s surface area.
If you notice the above aspects, that is to say, you are concerning the durability of feed pellets. Any questions, please feel free to contact us.