In simple terms, the feed pellet machine, also known as the pelletizer, just compresses the material into pellets by extrusion, so the maturity of the material is very low. It is a feed processing machine that can use corn, soybean meal, straw, grass, rice husk, etc. as raw materials to directly pulverize the raw materials into pellets. The feed pellet machine is widely used in large, medium, and small breeding, grain and feed processing plants, animal husbandry farms, poultry farms, etc. The granulator has a simple structure, wide adaptability, and low noise. The most important thing is that granulation can be done without adding liquid (water) during production, so the moisture of pelleted feed is basically the moisture of the material before granulation, which is more conducive to storage.
The extruder uses a screw to fully mature the material by cutting, compressing, and kneading. After pelletizing, the material is expanded using screw compression ratio and aspect ratio. The extruded material has a very high maturity, which is conducive to digestion and absorption. A type of extruder called a feed extruder is commonly used to extrude food, aquatic and pet food or single ingredients. Fish feed extruders are available in a variety of dry and wet models for large, medium, and small farms as well as feed and food manufacturers.
1) The feed pellet machine uses a die to compress the raw material into dense pellets. Granular binders are often required in formulations to aid cohesion of the granules.
2) The extruder machine will reduce the density through significant starch gelatinization, swelling. In most cases, the addition of particulate binder is not required.
3) When making floating fish feed, the extruder can adjust the buoyancy of the granules by adjusting the degree of starch gelatinization, which is affected by many variables, including moisture content, extrusion temperature, amount of shear produced, and mould size.
4) Lower microbial load and palatability are essential for pet food, and squeezing improves both.
5) The extruder allows you to use more grease without producing a lot of pellets, increasing pellet integrity.
In conclusion, extruders are used for many purposes and molding is only one of them, but pelletizers are mainly used for molding or producing pellets. An extruder is often referred to as a fish feed extruder because it produces floating feed, while a pellet mill includes all feed equipment (including sinking feed).