The WFM technology (Wet extrusion of feed mixtures) is designed for the production of granulated feeds. Typical entry materials include complete compound feed for livestock (especially pigs and poultry), pets (pet food), and fish (fish feed). These mixtures may contain fats and proteins of both animal and plant origin, cereal meals, vitamins, minerals, prebiotics, colorants, enzymes, medicines, and other components.
Individual components together form a homogeneous complex, shaped into a granule. Granules may be shaped via matrices into diverse shapes and sizes. Setting the extrusion parameters can also adjust certain properties of extruded feed, such as producing either floating or sinking fish feed.
The technology of wet extrusion produced by Farmet stems from the company’s extensive experience and has been popular with our customers for many years. The importance of extrusion lies mostly in feed industry. It is used for all categories of livestock and pet animals. Wet extrusion works best with materials and mixtures containing up to 15 % of oil.
Processed material is continuously supplied into the extruder. In wet extrusion, either water is added through a nozzle, or steam is injected into the chambers of the extruder. An option for increasing effectiveness of wet extrusion is to use the steam conditioner, which heats up the material prior to extrusion and also increases humidity to desired levels.
In the extruder, the material is compressed, ground, kneaded and heated up by friction. Due to the high pressure in the machine, water stays liquid even at temperatures above 100 °C. Heating up of the material by friction is quick and even. This short exposure to high temperature and pressure causes protein and starch transformation as well as a reduction of anti-nutritional substances.
The heated and compressed material exits the extruder continuously. At the outlet, intensive expansion occurs. Once the material leaves the extruder through the outlet nozzle into the open air, water evaporates immediately. The material expands, including the water contained inside the cells. This leads to a disruption of cellular structures and starch and protein transformation, which subsequently improves nutritional values of the feed.
If the material contains connective substances, such as starch, it is possible, by means of particular shapes of outlet nozzle (or a die) and added cutters, to effectively shape the feed into granules of manifold shapes.
The company Farmet offers optional accessories that will satisfy even the most demanding customers. Nonetheless, the most convenient solutions are usually our turnkey deliveries, which are optimized from both the technical and economic perspectives, meet all your requirements and include the automatization of the entire process.
Extruders are offered at capacities between 90 and 8,400 kg of extrudate per hour. They can be assembled in an array, which increases the overall extrusion capacity. As standard, they are designed to meet EU specifications; however, they can be adjusted to wiring requirements of local markets (e.g. USA, Canada, etc.).
