The influence of the ring die on pellet production

The influence of the ring die on the quality of the feed pellets is mainly manifested in the length, diameter, flatness, spacing and shape of the die hole.

1. Die hole length

The longer the material is extruded in the die hole, the harder the finished particles will be and the better the strength will be. On the contrary, the particles will be loose and the pulverisation rate will be high.

2. Flatness of the die

The lower the roughness of the die hole, the smoother the granules produced, which are easy to extrude, not easy to crack and the granules are better granulated.

3. Die hole diameter

For a thick ring die, the smaller the ratio of die hole length to hole diameter, the larger the hole diameter, the easier it is for the material to line up in the hole, and the smoother the surface of the finished particle, it is not easy to crack and the quality is good.

4. Hole spacing

The distance between the die holes is related to the properties of the pressed feed. When the feed with small wear is pressed, the ring die with very close hole spacing can be used. If the feed with large wear is pressed, the ring die with large hole distance should be used, such as feed with high mineral content and fibre material.

5. The shape of die hole

The shape of die hole mainly includes four types: straight hole, stepped hole, inner tapered hole and outer tapered hole. Straight holes have moderate performance, are easy to manufacture and are the most widely used; stepped holes reduce the length of the die hole and shorten the extrusion time of the material; the inner tapered hole has high extrusion density, high hardness and low pulverisation rate; the outer tapered shape is advantageous The particles pass through, the extrusion density is small and the hardness is low.