There are the following reasons caused that materials don't off-line after briquetting: The water content of materials is improper. Solution: in general, the water content should be controlled in the range of 8% to 13%. If the materials contain more water, it can be drying by dryer if there are a lot of materials, while it can be drying naturally to save cost. The roller of the briquette machine is designed improper or the ball socket is too small. Solution: when choosing the briquetting machine, it should be better to choose the briquette machine with the ball socket diameter more than 3 cm. The briquetting machine rotates at a low speed. Solution: the rotating speed of the briquette machine should be set at 10 to 20 per minute.