Flat die pelleting machine
Flat die pellet mills have become the preferred pelleting equipment for small and medium-sized production enterprises due to their simple structure, low cost, and wide applicability to materials (organic fertilizer, biomass fuel, etc.). This equipment adopts a screw pressure regulating mechanism and a "cone wheel flat die" structural design, adjusting the die gap to meet the pressing requirements of different materials. The core pressure roller assembly uses a multi-distributed structure, possessing the characteristics of pressure resistance, wear resistance, and stable operation.

Structural Disassembly and Component Description

From an operation and maintenance perspective, a flat die pellet mill can be divided into the following modules:

(I) Forming Module: Includes the flat die and pressure rollers. The flat die and pressure rollers are typically made of high-quality alloy steel and heat-treated for high hardness. Different die diameters can be selected as needed.

(II) Transmission Module: Includes the motor, reducer, belt drive mechanism, and bearing system. Some models use high-precision gear transmission and are equipped with a hydraulic automatic circulating oil supply system.

(III) Pressure Adjustment Module: Includes the screw center pressure adjustment mechanism and a spring or hydraulic system. Used to adjust the die gap to accommodate different materials.

(IV) Cutting and Discharge Module: Includes the cutter and sweeping plate. Used to cut the extruded material and discharge it from the machine.

(V) Machine Body Module: Includes the frame, shell, observation door, etc. The machine body has a robust cast structure.

Application scenarios and applicable industries
Flat die pellet mills are widely used in the production of organic fertilizer, bio-organic fertilizer, and organic-inorganic compound fertilizer pellets; the processing of feed and forage pellets; the production of biomass fuel pellets such as sawdust and straw; and the treatment of waste pellets such as rubber and plastics. The equipment is multi-functional and adaptable to a wide range of raw materials.

Common material types
Flat die pellet mills can process a variety of materials: composted livestock and poultry manure, straw powder, sawdust, rice husks, cotton stalks, weeds and other coarse fiber materials; feed ingredients such as corn flour, soybean meal, bran, grass powder and other feed ingredients; waste such as household garbage and waste plastics; and fertilizer ingredients such as bio-fertilizer, organic fertilizer, and compound fertilizer.

Working mechanism and operating logic
The working principle of a flat die pellet mill is as follows: the main motor drives the belt and pulley, transmitting power to the drive shaft via a reducer. Pressure rollers mounted on the drive shaft work in opposite directions against the flat die plate. Under the pressure, the material is forced into the die holes on the flat die plate and compacted. The formed pellets are then cut and scraped out from the bottom of the die holes by a scraper, achieving continuous pelleting. Feeding relies on the material's own gravity to avoid clogging.

Target user profile
Primarily targeting small and medium-sized organic fertilizer plants, feed processing plants, biomass fuel pellet production enterprises, and livestock farms with an annual output of 10,000 to 50,000 tons. Suitable for small and medium-sized production entities that are sensitive to investment costs, have limited space, and wish to use one machine for multiple purposes.

Maintenance tips and schedule

Maintenance of the flat die pellet mill should be performed according to the following schedule:
Per-shift maintenance:After each shift, clean the machine surface of dust and material residue; check for loose bolts; add an appropriate amount of high-temperature grease to the pressure roller bearings; add lithium-based grease to the pressure roller bearings and die plate bearings (once per shift, filling 1/3 of the bearing space).

Weekly maintenance:Check the wear of the flat die and pressure rollers; record the wear amount and running time; replace parts promptly if wear is severe.

Monthly maintenance:Add lubricating oil to the transmission system to reduce component friction; check the belt tension; check for oil leaks in the gearbox.

Daily precautions:Ensure the raw materials do not contain stones, iron blocks, or other hard objects; during pelleting, the pressure rollers must not idle in contact with the die plate; after every ten or so shifts (8 hours per shift), disassemble the rollers and apply high-temperature grease to the bearings.
Summary of common faults

Flat die pellet mills are prone to the following malfunctions:

(I) No pellets produced or low pellet output: This is often due to excessive moisture content in the raw material (>30%) leading to clogged die holes, uneven raw material particle size, or excessive gap between the pressure roller and the die (more than 1mm).

(II) Loose and brittle pellets: This is often due to insufficient pressure from the pressure roller (normal operating pressure should be 8-12MPa), poor raw material viscosity (coarse fiber content >60%), or worn die holes.

(III) Rough pellet surface: This is often due to poor die hole smoothness during initial use of the flat die, or severe wear of the pressure roller or flat die.

(IV) Equipment vibration and abnormal noise: This is often due to foreign objects entering the machine, damaged pressure rollers, loose anchor bolts, or damaged bearings.

(V) Transmission system malfunctions: This is often due to loose belts, broken chains, or worn gears. 10. Troubleshooting and Repair Solutions

For the above-mentioned faults, the solutions are as follows:

No pellets produced or low pellet output:Stop the machine, remove the mold, and manually clear the blockage with a drill bit slightly smaller than the mold hole; allow the material to dry or add 10%-15% dry material to reduce the moisture content to 20%-25%; calibrate the pressure roller gap to 0.3-0.5mm; filter large impurities with a vibrating screen (5mm mesh) before feeding.

Loose and brittle pellets:Check the spring compression (normally should be 60%-70% of the free length); replace the spring if the elasticity is insufficient; adjust the overflow valve if the hydraulic system pressure is insufficient; appropriately add viscous substances (such as humic acid or manure).

Rough pellet surface:Increase the moisture content or replace the flat mold.

Equipment vibration and abnormal noise:Open the cover to check for foreign objects; replace damaged pressure rollers or bearings.

Uneven particle length: Adjust the cutter position and keep the distance between the cutter and the flat die at 0.5-1mm by adjusting the bolt; check the wear of the cutter regularly and replace it in time (it is recommended to replace it every 500 hours).