The raw materials used in pellet machines directly affect pellet quality; only by controlling the raw materials can high-quality pellets be produced. Therefore, higher requirements are placed on the raw materials for pellet machines to produce high-quality pellets. So, what are the requirements for raw materials used in pellet machines?
Moisture requirements vary by raw material.
The moisture content of biomass raw materials shall not exceed 15%.
For sawdust, the ideal range is 10%–15%: 10%–14% for softwood and 8%–12% for hardwood.
Too much moisture creates fragile loose pellets; too little causes hard compaction and excess fines.
The maximum particle size of the raw material must not exceed the diameter of the pellet machine ring die hole to prevent die blockage and poor pelleting.
It is strictly forbidden to mix hard impurities such as iron blocks and stones into the raw materials to avoid wear and damage to the pellet machine.
Softwood chips and softwood shavings are preferred as raw materials, as softwood is easier to extrude and produces higher pellet formation rates.