Pressure Rollers

Pressure rollers are cylindrical components mounted on rotating shafts within pellet mill die assemblies. They apply compressive force to raw materials (such as wood, agricultural residues, or feed ingredients) against a perforated die, forcing the material through die holes to form uniform pellets. In high-capacity pellet mills, these rollers are engineered to withstand extreme pressure (typically 2,000-5,000 psi), high temperatures (up to 120°C), and continuous operation while maintaining precise gap control with the die surface.

Pressure rollers operate on the principle of mechanical compression and friction. As the die rotates (in ring-die mills) or the rollers rotate (in flat-die mills), raw material is fed between the rollers and the die surface. The rollers apply radial force, compressing the material against the die. This compression increases material density, generates heat through friction (aiding lignin activation in biomass), and forces the material through die holes where it's cut to length by adjustable knives. The gap between rollers and die (typically 0.1-0.3 mm) is precisely controlled to optimize compression while minimizing wear.