Fish Feed Extrusion Process Origin
What is Fish Feed Extrusion Process
Commercial fish feed extrusion process refers to cook the mixture of feed ingredients under high temperature, moisture and high pressure by means of fish feed extruder within short time, whereby the high temperature is a direct result of friction(dry extrusion) or preconditioning and steam injection (wet extrusion). As a technological treatment, extrusion can make it possible to process a variety of fish feed ingredients, such as soybean, corn, rice, peas and raw materials with high water content. According to the moisture content of raw materials treatment, fish feed extrusion process can be divided into two types – dry type extrusion and wet type extrusion.
- Dry type extrusion process: in the process of extruding, it adopts the heat from friction for warming materials, forces materials to pass through die hole and gets certain pressure simultaneously under the action of screw extrusion. After extruding out of die hole, materials pressure will decrease sharply and moisture will evaporate so as to achieve the goal of extrusion. During this whole process, water content is always about 15% – 20%.
- Wet type extrusion process: its principle is similar to that of dry type extrusion, but it needs to add water and vapor to make moisture up to 20% or even over 30% because the rising of materials temperature depends on the addition of vapor.
Equipment – Fish Feed Extruder
Currently, the main extrusion equipment applied in aquatic feed production is single screw fish feed extruder which is also divided into dry type fish feed extruder and wet type fish feed extruder machine. With different parameters and feed formulation, fish farmers and feed plants can make floating, sinking and slow-sinking feed with high quality and nutrition so as to adapt for diverse ingestion requirements of various aquatic animals. Adopting alloy steel as material, FANWAY dry type fish feed extruder has been widely used in small-scale and medium-scale fish farm or feed plants to produce aqua feed and also dog/cat pet feed in virtue of its simple structure and low noise. Other than dry type, the wet type fish feed extruder machine is equipped with a boiler that can add vapor constantly into chamber when extruding feed ingredients, which makes it widely applied to produce floating fish feed pellets for fish farm, aquaculture and even poultry farms.
Tips when operating fish feed extruder:
- Pay more attention to safety. Stay away from feed inlet when machine runs. For adding raw materials, operators should use a stick rather than use hand.
- The raw materials should be added before machine running.
- When blocking, please turn down the extruder instantly.
- Remember to check the degree of tightness elasticity of belt, avoiding capacity decrease caused by belt slipping.
- Regularly change the lubricating oil for machine.
Adavantage of Extruded Fish Feed
The basic function of fish feed produced through extrusion process is to kill the germ, mycete and fungus in feed ingredients, improve the hygienic quality and provide safe fodder for fish and other aquatic animals. Besides, there are some other obvious advantages of extruded aqua feed:
- High digestive utilization ratio: in the process of extruding, the heat, steam, pressure and other mechanical actions can promote the degree of starch pasting, break and soften the cell wall part of fiber structure and release some digestible materials, which is in favor of the digestion and absorption for aquatic livestock.
- Slight pollution to environment: with good stability in water, extruded fish feed makes it possible to decrease the dissolution and sediment of feed nutrition and then reduce loss and waste, alleviating water pollution.
- Convenient feeding management: extruded fish feed can float on water for a long time, which makes it easier to observe fish ingestion so as to adjust feeding quantity timely and master fish growth and health state.
In addition, with longer and easier storage period, fish feed via extrusion process, including floating, sinking and slow sinking types, also can satisfy different demands of aquatic animals with various ingestion habits. All in all, extruded fish feed has gained great popularity among fish farms and other aquaculture industry around the world.