Pet food extruder

Extrusion cooking is the predominant method of producing pet food worldwide. Before the extrusion process, the ingredients are ground and mixed. Before the dry mixture enters the extruder barrel, a preconditioning stage takes place. In this phase, steam is used for heating and thorough mixing occurs, leaving enough time for hydration. This crucial step in the extrusion process ensures the optimal texture and quality of the final pet food product. Additionally, it helps improve the nutritional profile and digestibility of food.

When cooking dry pet food, commonly known as kibble, there are two main methods: extruding and baking. The majority of pet food available on the market is produced using the extrusion process. On the other hand, baking is a less commonly used method of preparing pet food. These two techniques offer distinct advantages and result in different textures and properties of the final product.

To initiate the cooking process, steam is introduced, while the preconditioned mixture (extrudate) is then conveyed through an extruder. The extruder consists of a solid, rotating screw that fits snugly into a stationary barrel and ends in the nozzle. The rotational movement of the extruder screw drives the extrudate through the system.

The composition of a comprehensive extrusion system varies depending on the products to be processed. Typically it includes storage containers, dry ingredient feeders, liquid pumps and meters, a preparation unit, an extrusion assembly, a molding device and a cutting mechanism. These components combine to form a complete extrusion system suitable for a variety of food processing applications.

There are two main categories of extruders: single screw and twin screw extruders, which include both co-rotating and counter-rotating configurations. These extruder types have a diverse selection of screw sizes (diameters), lengths and designs.