The production raw materials have mildew If the raw materials used are mildewed, it will also cause the wood pellets to turn black.Although the pellet fuel produced by this reason has good gloss and no cracks on the surface, the calorific value is reduced due to mildew, which will affect the use.
The compression ratio of ring die becomes larger If the compression ratio of the ring die becomes larger, the resistance of the wood pellets through the ring die will increase. At this time, the resistance of the wood pellets through the ring die must be overcome, and the wood pellets will turn black due to carbonization. Of course, although the pellet fuel caused by this factor has turned black, it will not affect the quality of the pellet fuel and will increase the calorific value of the pellet fuel. However, there is also a disadvantage that the output of the wood pellet machine is low and the ring die is worn out.