The Press Roller Skin, a Common Wearing Part of Ring Die Biomass Pellet Machines
The Function and Necessity of Press Roller Skin Replacement
The press roller skin is a core, wearable part of a ring die biomass pellet machine. It works with the ring die to extrude and shape raw materials (such as wood chips and straw). Its surface, with its teeth and grooves, increases friction, forcing the material into the die holes and forming high-density pellets. Due to long-term exposure to high pressure, high temperature, and abrasion from hard impurities in the raw material (such as sand, gravel, and metal debris), the press roller skin’s surface gradually wears out and fails, resulting in a decrease in pellet formation efficiency, increased energy consumption, and even abnormal equipment vibration. Therefore, regular replacement is necessary based on frequency of use and raw material characteristics to ensure pellet quality and equipment efficiency.Common Types of Press Roller Skins
Currently, mainstream press roller skins are divided into two categories based on the process:| Ordinary press roller skins | Welded Roller Skin (Overlay Type) |
| These use a one-piece casting process and have a toothed surface. This toothed surface offers high winding efficiency, but wear can lead to uneven material distribution. 65Mn (65 manganese) is commonly used. | A high-hardness, wear-resistant alloy layer is welded onto the surface of the base material, increasing wear resistance by more than 2 times. This method allows for localized repair welding of worn areas, reducing overall replacement costs. It is suitable for highly corrosive raw materials (such as palm oil and rice husks). |
Key Maintenance and Care Measures
Extending the life of the roller skin requires a combination of daily maintenance and standardized operation:Regular Cleaning and Lubrication
Remove residue from the roller surface and pelletizing chamber after each shift to prevent debris such as stones, metal, and nails from accumulating in the pelletizing chamber. Pay attention to the oil level in the automatic grease pump to ensure it does not run out of oil and cause bearing damage. The automatic grease pump should be operated at a -40° to 200° angle to extend the life of the roller skin.
Gap and Alignment Adjustment
The gap between the roller and the ring die should be maintained at 0.1-0.3mm. A gap too large reduces molding efficiency, while a gap too small increases wear.
Raw Material Pretreatment
Remove metallic impurities through a de-ironing device and screening equipment, and control the moisture content of the raw materials to between 8% and 20%. A gap too high can easily block the die, while a gap too low can increase roller friction.
Abnormal Warning and Handling
If the equipment experiences unusual noises or current fluctuations, immediately stop the machine and inspect the roller surface for dents or bearing damage to avoid collateral damage to the ring die.