The Cooling Purpose and Characteristics of the Extruder Barrel

Extruder barrels are used in large twin screw extruders. The purpose of adopting this type of segmented combined extruder barrel is to facilitate the machining of the extruder barrel and save some more precious alloy steel.

On the meshing co-rotating twin-screw extruder, the layout of the extruder barrel is mostly segmented, and the extruder barrel is composed of several sections of equal length. The material port, some extruder barrels have an exhaust port or an increase agent port.

Ⅰ. The purpose of cooling the extruder barrel

It is to prevent the heat generated in the hopper from being too high due to forced feeding; in addition, it is also to prevent the temperature of the extruder screw feeding section from being too high. The temperature of these two parts is too high, which will mainly affect the feeding of the hopper and the forward running and conveying of the pellets entering the screw feeding section of the extruder.

The cooling of the extruder barrel includes the cooling of the extrusion plasticizing part in the extruder barrel, the cooling of the hopper seat and the cooling of the extruder screw.

Ⅱ. Cooling of the extrusion plasticizing part in the extruder barrel

The cooling of the plasticizing part is mainly a cooling measure to prevent the temperature of the extruder barrel from being too high during operation. There are two cooling methods: water cooling and air cooling. At present, the most widely used method is air cooling.

The way of air cooling is to use the fan to directly blow the part of the extruder screw barrel that needs to be cooled down, and the cold air will take away the heat of the extruder barrel, so as to achieve the purpose of cooling the extruder barrel. The method of fan cooling the extruder barrel is simple, the equipment structure is simple, the thermal shock to the extruder barrel is small, the cost is not high, and the maintenance and production operations are relatively convenient.

Ⅲ. Working characteristics of extruder barrel

1. The screw speed of the extruder can be configured as stepless pressure and speed regulation.

2. The linear guide rail injection replaces the guide column injection, which reduces the friction during injection and improves the injection accuracy (optional).

3. The screw barrel of the extruder is made of alloy material, which is quenched and tempered and desalinated to improve the wear resistance. The injection adopts the electronic ruler of Jeffren, Italy, and the position control accuracy can be controlled within 0.1mm.

4. The 4-stage injection pressure and speed, and the 4-stage holding pressure and speed are independently controlled, which is more conducive to the adjustment of the injection process.

5. Manual back pressure device (optional for CNC back pressure) improves the plasticization, exhaust and density of plastics by the extruder screw. After feeding, a back pressure elimination device is added to prevent the plastic from flowing into the mold to produce cold material when the feeding back pressure is used in the production of products without loosening.

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