What's the Difference Between Single Screw Extruder and Double Screw Extruder for Cat Dog Fish Feed?

The extruder is mainly composed of a barrel and a screw rotating in the extruder barrel, there are single screw extruder and twin screw extruder two categories. In the process of extrusion processing, the material from the feeding port into the die cavity, driven forward by the screw conveyor, by extrusion, mixing, compression and shear. Due to the driving force, friction and shear force and the effect of external heating, the material becomes heated under pressure, reaching the high temperature and high pressure state, and becomes a modified paste. When the material is extruded from the front die hole, due to the temperature and pressure suddenly drop to normal temperature, atmospheric pressure state, resulting in rapid evaporation of water in the material, rapid volume expansion, become puffed.

Single screw extruder has no gearbox, one shaft, triangle start; twin screw dog food equipment, gearbox control, two shafts, frequency conversion control. The twin-screw dog food equipment is more stable, and the feed/food made is smooth in appearance and has a good degree of ripening.

From the analysis of the characteristics of single-screw and twin-screw extrusion, it can be seen that the twin-screw extruder has the following advantages:

1. The material is more adaptable and can be adapted to high viscosity, low viscosity, high grease content, high moisture or viscous, oily, very wet and other raw materials that can slip in single screw (SSE).

2. The particle size limitation of the raw material is less, and it can be adapted to the processing of raw materials having a wide particle size or a raw material from the fine powder to the coarse powder particles and a particle size outside the specific range of the single screw processing.

3. The material flow is more uniform in the barrel, which can be more accurately scaled and achieve the actual demand effect regardless of the addition of steam, water and other auxiliary processing.

4. The product has better internal and appearance quality, can achieve very good homogenization state and make the material molecular structure uniform, the surface is smooth during the extrusion process, the product particles are uniform and the uniformity is good.

5. The ripening and homogenization effect is better. Generally, the starch ripening degree can reach more than 95%, so that the processed aquatic feed can be kept stable in water and the nutrients of the product are not lost and easily digested and absorbed.

6. The output is higher under the same power, and the good mixing performance makes the heat obtained by the material uniform in time, accelerates the degree of ripening of the material, reduces the fluctuation of the material temperature, and improves the output of the extruded product.

7. Product diversity and adaptability, can process micro-aquatic feed, high oil formula, high moisture, high adhesion products and multi-color, sandwich, special shape products.

8. The process operation is simpler, the spindle speed can be adjusted according to the demand of the processed products. Due to the self-cleaning characteristics, the cleaning is very convenient, and there is no need to disassemble the equipment after each processing.

9. Consumable parts wear lighter, usually a misconception that the single screw wears less, in fact, in the twin-screw extrusion process, due to the stable material transport and material flow characteristics, the material is determined to the screw and the barrel. The wear of the sleeve is smaller than that of the single screw. Although it is one more than the screw, the cost of the accessory is still lower than that of the single screw.

10. The production cost is lower, because the twin-screw model has good operational stability, less start-up cost, less water and gas waste, less labor time, high heat transfer efficiency, high yield, and electricity output in the feed processing process. High indicators, coupled with low cost of accessories, and their final production costs are still much lower than single-screw.