First, clean and fill the die holes after every shutdown. Run a mix of oily mash or fine sand and oil through the machine in the last minutes of production so the holes are left packed with an abrasive-oily paste instead of damp raw material — dried feed swells, blocks the holes and rusts them from inside. Second, keep metal and stones out of the raw material: a magnet and a simple screen before the grinder stop nails and grit from scoring the die surface and chipping the roller shells. Third, control moisture. For biomass and wood pellets, material dried to roughly 8–12% moisture presses cleanly; wetter feed slips, blocks and corrodes the die, while overly dry feed over-wears the holes. The photo shows a die and roller assembly mid-production — uniform extrusion like this only happens on a clean, well-maintained die.

Fourth, check the roller-to-die gap and the lubrication schedule. Rollers that float too far from the die spin without pressing, while a gap set too tight burns the die face; follow the manual's clearance and grease the roller bearings on time. Fifth, keep one spare die on the shelf. A die change takes minutes when the spare is in stock, but days if you must order one and wait — and during those days the whole line stands still. Weiwei Machinery supplies dies, rollers and complete spare-part kits for its flat die and ring die pellet mills, and our engineers can advise the right compression ratio and hole size for your material. Contact the export team or visit weiweimachinery.com.