Flat Die Pelleting Machine

The flat die pelleting machine is an extrusion-type machine specifically designed for granulating organic materials; it is commonly found in processing facilities attached to livestock farms and in small-to-medium-sized organic fertilizer workshops. It performs heavy-duty work—forcing loose organic materials (such as fermented chicken, sheep, or cattle manure and powdered straw) through a perforated circular die plate and cutting them into cylindrical pellets. Although compact and simple in structure, the machine is highly effective at handling organic materials with high fiber content and moisture levels. Its greatest advantage is its versatility regarding feedstocks; it accepts fermented materials with varying moisture levels, avoiding the strict moisture requirements associated with other granulation processes. For livestock farmers and small entrepreneurs with limited capital who wish to enter the organic fertilizer business, the flat die pelleting machine is a reliable, practical choice.

Working Principle of Flat Die Pelleting Machine

The core operation of the flat die pelleting machine can be summarized in three actions: pressing, extruding, and cutting. After entering the granulation chamber, the material lands on a horizontal circular die plate; the main motor drives the die plate to rotate at a constant speed via a gearbox. The pressure rollers above the die plate are not directly driven by the motor but rotate passively through friction generated between the material, the rollers, and the die plate. As material is drawn into the gap between the rollers and the die plate, the rollers exert powerful crushing force, compacting the loose material and forcibly extruding it into the die holes. Inside the holes, the material undergoes a brief compression and shaping process; as it is compacted and moves downward, it is continuously extruded from the bottom of the die plate as dense cylindrical strands. Simultaneously, a cutter mounted beneath the die plate slices the extruded strands to the desired length, and the finished pellets fall into the discharge outlet.

Common Issues for Flat Die Pelleting Machine

Pellet discharge is sluggish or output is significantly low after using a new machine or a newly replaced die plate: This is usually because the inner walls of the die holes have not yet been “broken in,” resulting in excessive resistance. Running an oil-and-fine-sand mixture through the machine several times to polish the inner walls of the die holes will smooth out the discharge process.

Pellet surfaces are fuzzy or cracked, or pellets break easily: This is typically caused by the material having too low a moisture content or the fibers being excessively long. If the material is too dry, the particles fail to bond securely; they are often cut off before they can properly form. Increasing the material’s moisture content or re-grinding raw materials with long fibers will significantly improve the appearance and strength of the pellets.

Abnormal roller bouncing: This issue often stems from the roller bearings. Operating in a high-temperature, dusty environment under heavy loads, these bearings wear out rapidly if lubrication is insufficient, causing the rollers to rotate sluggishly or even seize up. Immediate shutdown and inspection are required, and worn bearings must be replaced promptly.

Intermittent pellet output and fluctuating production rates: This is usually caused by material bridging in the hopper. Organic materials with high fiber content often have poor flowability, leading to situations where the material arches over and fails to feed down. Installing a feeder with an anti-bridging function or manually agitating the material with a rod can ensure consistent feeding.