Why are twin-screw extruders more suitable for the production of pet meat-based foods?

In the field of pet food production, the composition of raw materials has distinct characteristics, among which meat products dominate. This type of raw material gives the product a strong viscosity, which poses a severe challenge to the processing equipment. When facing such raw materials, single-screw extruders often find it difficult to achieve economical and efficient production, while twin-screw extruders have become an ideal choice for the production of pet meat-based foods with their unique performance advantages.

The meat product raw materials in pet food, because they are rich in organic components such as protein and fat, show physical properties that are completely different from those of ordinary grain raw materials during processing. Meat products are prone to adhesion and agglomeration under heat, pressure and mechanical action, which not only increases the difficulty of material transportation, but also may cause unevenness during processing and affect product quality. Single-screw extruders usually rely on the rotation of a single screw to push the material forward and perform extrusion processing. When processing highly viscous meat product raw materials, it is difficult for a single screw to effectively and evenly transport the material, and it is easy to have problems such as material accumulation and blockage. Moreover, the shearing effect of a single-screw extruder is relatively concentrated and strong. For meat products, which are soft and viscous raw materials, excessive shearing may damage the organizational structure of the meat products, resulting in the loss of nutrients, and also affect the taste and appearance of the products.

In sharp contrast, the design of the twin-screw extruder fully considers the processing needs of viscous materials. One of its most significant advantages is the reduction of the shear range. The twin-screw extruder makes the flow path of the material in the barrel more complex and reasonable through the coordinated work of the two screws. Under the push of the screw, part of the material forms a C-shaped material flow along the inner wall of the sleeve, and the other part flows through the gap of the meshing part of the screw. This unique flow mode avoids excessive shearing of the material in local areas. For meat product raw materials, gentle and uniform shearing can not only ensure the full mixing of the material, but also retain the original structure and nutrients of the meat product to the greatest extent. For example, when producing pet food with fresh meat as the main raw material, the twin-screw extruder can evenly mix the minced meat with other ingredients while maintaining the integrity of the meat fiber, making the final product closer to the natural diet of pets in terms of taste and nutrition.

Twin-screw extruders also have a more effective pumping effect. The two screws work together like two closely cooperating conveyors, which can generate a strong and stable driving force to smoothly convey the viscous material forward. In the production of pet food, whether it is fresh meat, meat powder or raw materials with high fat content, the twin-screw extruder can easily cope with it, ensuring that the material maintains a continuous and stable flow state throughout the processing process. This efficient pumping capacity not only improves production efficiency, but also ensures the consistency of product quality. When producing pet food on a large scale, stable material delivery is the key to achieving standardized production, and this feature of the twin-screw extruder just meets this need.

In addition, the self-wiping effect of the aquafeed petfood twin-screw extruder machine is also an important factor that makes it stand out in the production of pet meat-based food. During the production process, the meshing and relative movement of the two screws can automatically remove the materials attached to the screw surface and the inner wall of the barrel. This function is particularly important for meat product raw materials with strong viscosity. It effectively avoids the residue and accumulation of materials inside the equipment, and reduces the risk of microbial growth and product contamination caused by material residues. At the same time, the self-wiping effect can also ensure that the equipment always maintains a good working condition during long-term continuous operation, reducing the frequency of equipment maintenance and cleaning, and further improving production efficiency.

In the actual production process, these advantages of the twin-screw extruder are fully reflected. From the pretreatment of raw materials to the molding of the final product, the twin-screw extruder can complete a series of complex processing procedures. Fresh meat, meat powder, grain powder, oil and fat, and various nutritional additives are mixed in proportion and sent to the twin-screw extruder. In the barrel, the material is driven by the screw and undergoes the processes of conveying, mixing, shearing, heating, and puffing in turn. Due to the special structure and working principle of the twin-screw extruder, the material can be fully cooked and evenly mixed under suitable temperature, pressure and shear conditions, and finally extruded through the die hole to form pet food particles of various shapes and specifications.