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Reasons for the Production of Unshaped Wood Pellets
2015-04-03wood pelletizing process,some unshaped wood pellets may be produced. Many factors lead to this phenomenon, including characteristic of the raw materials, compression ratio of the die, clearance between roller and die, etc.
Moisture content of raw material is an important index when pelletizing. Generally, it is required that moisture content is 10-20%. Of course, this is not always true, depending on the raw materials. For example, when we pelletize the pine, cedarwood and eucalyptus, the moisture content of 13-17% is required. If you have any doubt, contact us freely. Our professionals will give you the corresponding answer to satisfy your specific demands.
Another influence factor is the raw material itself. The raw materials with soft texture are easy to be pelletized. Conversely, the too hard raw material can be shaped through mixing with some wood shavings. Different raw materials are different in characteristics, fiber structure and shaping difficulty. Therefore, if the raw materials are more than one, mixing ratio of various ingredients also influence the shaping rate.
Compression ratio refers to the ratio between the length and diameter of die holes. The larger is the compression ratio, the thicker is the die. Therefore, the pelletizing time will be longer, ensuring high shaping rate. Different raw materials need different compression ratio.
Clearance between roller and die is also crucial when pelletizing. Generally, the clearance of 0.1-0.3mm is optimum. Too large clearance lead to unsufficient pressure, making it difficult to extrude the materials into pellets. Too small clearance may improve the density and smoothness, while it can accelerate the wear between roller and die, decrease the service life of machine and affect the pelletizing capacity.
Moisture content of raw material is an important index when pelletizing. Generally, it is required that moisture content is 10-20%. Of course, this is not always true, depending on the raw materials. For example, when we pelletize the pine, cedarwood and eucalyptus, the moisture content of 13-17% is required. If you have any doubt, contact us freely. Our professionals will give you the corresponding answer to satisfy your specific demands.
Another influence factor is the raw material itself. The raw materials with soft texture are easy to be pelletized. Conversely, the too hard raw material can be shaped through mixing with some wood shavings. Different raw materials are different in characteristics, fiber structure and shaping difficulty. Therefore, if the raw materials are more than one, mixing ratio of various ingredients also influence the shaping rate.
Compression ratio refers to the ratio between the length and diameter of die holes. The larger is the compression ratio, the thicker is the die. Therefore, the pelletizing time will be longer, ensuring high shaping rate. Different raw materials need different compression ratio.
Clearance between roller and die is also crucial when pelletizing. Generally, the clearance of 0.1-0.3mm is optimum. Too large clearance lead to unsufficient pressure, making it difficult to extrude the materials into pellets. Too small clearance may improve the density and smoothness, while it can accelerate the wear between roller and die, decrease the service life of machine and affect the pelletizing capacity.