company news about What Is a wet pet food processing machine?

The core definition and applicable scenarios of wet dog food production machines. Wet pellet mills are devices that use the bridging effect of liquid binders to aggregate powdered raw materials into pellets with a certain strength and uniform particle size. Their core advantages are good pellet formation and controllable hardness, making them suitable for producing sinking, hard pellet feed, catering to the needs of bottom-dwelling fish such as grass carp and common carp, as well as livestock such as pigs and cattle. Unlike extruders, which use high temperature and high pressure for extrusion, wet pellet mills do not require extreme operating conditions and can retain heat-sensitive nutrients to the greatest extent. Therefore, they occupy an important position in the production of high-end young animal feed and specialty aquatic feed. For example, when producing starter feed for piglets, wet pellet mills can control the pellet hardness to within 2kg while retaining the activity of vitamins and enzymes, whereas the high-temperature environment of extruders easily leads to the loss of these components.

Core working principle: The complete process from raw materials to pellets. The workflow of a wet dog food processing machine can be summarized in four steps: mixing and wetting, extrusion granulation, drying and cooling, and screening and grading. The first step, mixing and wetting, involves feeding pre-treated powdered raw materials (80-100 mesh) into a mixing device and evenly spraying a quantitative binder (usually 10%-15% of the raw material weight) until the material is moistened to the point where it can be formed into a clump when squeezed but crumbles easily when touched. The second step, extrusion granulation, involves the moistened raw material being extruded through the die holes by the pressure rollers and die to form columnar granules. The particle size (1-5mm) can be adjusted by changing the die. The third step, drying and cooling, involves the freshly formed wet granules having a high moisture content (20%-25%), requiring drying to 12%-14% and then cooling to room temperature to prevent mold growth. The fourth step, screening and grading, involves using a vibrating screen to select granules of the appropriate size, while the broken pieces are returned for re-granulation to improve raw material utilization.

The core structure differs from that of an extruder. The wet fish feed extruder machine mainly consists of a feeding device, a mixing device, an extrusion granulation device, a drying and cooling device, and a screening device. Its core components are the pressure rollers and dies (flat dies and ring dies). It relies on mechanical extrusion molding and lacks a high-temperature, high-pressure chamber. In contrast, the extruder (single/twin screw) has a core structure of screw, barrel, and die head. The screw rotation generates extrusion and shearing force, which, combined with steam heating, creates a high-temperature, high-pressure environment, causing the raw material to expand and form. These structural differences determine the product characteristics of the two: wet pellet mill products have high density, no porous structure, and moderate water resistance (4-6 hours); extruder products have both buoyancy and sinking properties, stronger water resistance (8-12 hours), but a lower retention rate of heat-sensitive components compared to wet pellet mill products.

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