major factor:
1. Raw material factors
Raw material factors directly affect the effect of granulation. Materials with higher starch content are easy to be gelatinized by steam. After quenching and tempering, these raw materials have a certain viscosity, which is conducive to the formation of granules.
2. Feed flow control
In order to make the granulator work at full load without stopping, the flow of material entering the granulator must meet the granulation needs, and the feed structure must effectively eliminate the intermittent feeding caused by agglomeration.
3. Steam quality control
The use of steam granulation can effectively increase the output of the granulator and improve the quality of the granules. Steam is the source of water addition during conditioning and the heat source of gelatinization of feed starch. Adding a certain amount of steam to the conditioning can kill part of the bacteria in the feed, but also dilute the natural binder in the feed, so that every particle in the material forms a thin water layer outside, which is conducive to the gelatinization of the material. It is convenient for pelleting, thereby improving the quality of pellet feed.
Four, production operations
Correctly control the gap between the pressure roller and the mold. If the gap between the roller die is too small, the die and the pressure roller are easy to wear, and the super noise is large; if the gap is too large, the material extrusion will be affected. Generally controlled within 0.05～0.30mm. It can be measured with a feeler gauge during adjustment, or visual inspection without a feeler gauge.
5. Ring die
Whether the material can be squeezed through the die during the granulation process depends on the pressure and friction that can be generated in the die hole. This is related to the friction coefficient between the material and the die wall, moisture content, raw material size, temperature, buffer time of the plastic deformation part of the material, and compressibility of the material. These characteristics are closely related to the die hole depth and aperture.