Analysis of The Operating Principles of Twin-Screw Extrusion And Expansion Machinery: Key Processes From Raw Material Input To Expanded Product Formation

In the modern food and feed processing industry, twin-screw extrusion puffing machines have gained widespread application—thanks to their high efficiency, stability, and versatility—in the production of products such as pet food, aquatic feed, breakfast cereals, and textured protein.

In terms of principle, the twin-screw extrusion puffing machine transforms ordinary powdered raw materials into puffed products with stable structures and excellent palatability through a continuous process involving "conveying—mixing—cooking—puffing and shaping."

1. Raw Material Conveying and Uniform Mixing

Raw materials (such as corn flour, soybean meal, etc.) enter the extrusion system via a hopper. Driven by two intermeshing screws, these materials are thoroughly mixed with water, steam, or liquid additives to form a uniform, moist material matrix.

2. Extrusion Conveying and Pressure Generation

As the screws rotate and advance, the material is continuously conveyed into a progressively constricting spatial zone; during this process, it undergoes compression, causing the internal pressure within the system to rise steadily.

3. High-Temperature and High-Pressure Cooking Process

Through the combined action of heating elements and mechanical shear forces, the material's temperature rises rapidly. This triggers a series of physicochemical changes—such as starch gelatinization and protein denaturation—transforming the material into a fluid, molten state.

4. Extrusion Puffing and Shaping/Cutting

When the material is extruded through the die head, the internal pressure is instantly released; the moisture contained within the material rapidly vaporizes and expands, thereby creating a porous, fluffy structure. Subsequently, a cutting system performs precision cutting to achieve the desired product length.

After undergoing cooling and drying treatments, the final product acquires a stable physical form and the desired texture.

Equipment Advantages

Excellent Mixing Performance: The intermeshing twin-screw structure ensures uniform distribution of materials.

Stable Production Process: Possesses strong self-cleaning capabilities, effectively minimizing the risk of material blockage.

Broad Adaptability: By adjusting the screw configuration and process parameters, the machine can meet the production requirements of a wide variety of products.

Conclusion

Integrating mixing, cooking, and shaping functions into a single unit, the twin-screw extrusion puffing machine stands as a pivotal piece of equipment for achieving high-efficiency processing in the food and feed industries. By precisely controlling process parameters, it enables significant improvements in both product quality and production efficiency.