Flat die granulators often face die hole blockage during operation, which reduces production efficiency and can compromise product quality. Here are the main reasons behind this issue:

1. Material-Related Factors

Excessive moisture in the raw material is a primary cause. High moisture content makes materials sticky, leading to clogs as they pass through the die holes. For instance, biomass materials with high water content often form lumps inside the die holes. Particle size also matters: overly fine particles tend to compact and accumulate in the die holes, especially if the material contains sticky components like binders or oils.

2. Equipment Operation Issues

Improper die temperature setting of the flat die granulator plays a key role. If the temperature is too low, the material won’t soften or plasticize properly, reducing its flowability and causing blockages. For example, certain materials require controlled heat to form pellets smoothly—insufficient heat disrupts this process. Additionally, running the screw at excessively high speeds increases pressure inside the die holes, forcing material to pack tightly and clog the openings.

3. Die Design and Maintenance Problems

The roughness of the die hole surfaces affects material flow. Rough inner walls create friction, causing material to stick and accumulate. Over time, leftover material residues can build up in the die holes if not cleaned regularly, gradually narrowing or blocking the passages.

Understanding the causes of die hole blockage in flat die granulators will help to take targeted preventive and remedial measures during the production process and improve the working efficiency and production quality of the granulator.