1. Speed up drying stage: it is to use very high temperature to evaporate the water on the material surface in a relatively short time. This stage takes a relatively short time, but it is also limited to the water on the surface, so the water output at this stage is small.

  2、Constant speed drying stage: at this stage, the material is heated to make the water inside the material slowly replenish to the surface. Due to the high temperature heating on the material surface, the water on the material surface evaporates quickly. When the speed of replenishing water inside the material to the surface can not keep up with the speed of water evaporation on the material surface, it enters the speed reduction drying stage.

  3. Deceleration drying stage: in this stage, more than half of the material moisture has been evaporated. In this stage, the material is slowly dried, and the moisture inside the material is slowly forced to the surface and evaporated.
  4. Balanced drying stage: when the water inside the material is dried and there is no water to supplement the surface, it enters the balanced drying stage, which is the stage of obtaining the finished product after the material is dried.