With the continuous improvement of the production, manu […]
With the continuous improvement of the production, manufacturing, and processing technology of the twin-screw extruder, not only feeding and plasticizing, but also dewatering and drying processes must be carried out. In order to better meet the different needs of users, twin-screw extruders must continuously improve work efficiency and find ways to improve product quality. So how does the Nanjing twin-screw extruder perform temperature control?
How to control the temperature of the twin screw extruder?
1. The twin-screw extruder adopts the thermal resistance method to measure the temperature measurement points of the twin-screw extruder. At the corresponding position of the cylinder, there is usually a circular hole with a diameter of 5-6 mm, and a thermal resistance is inserted. In the entire extrusion process of the twin-screw extruder, strict temperature control and temperature control can maintain the main performance of the twin-screw extruder while also improving its production efficiency.
2. High polymer has poor heat transfer, which will cause viscosity loss due to shearing. This heat energy can only be discharged from the product, the barrel and the extruder screw through heat transfer, reflecting that the extrusion process is carried out under certain temperature conditions.
3. The temperature of the rear cylinder is more important because it affects the conveying speed of solid materials during meshing or feeding. All in all, part of the heat energy is supplied by the mechanical kinetic energy of the engine converted into heat energy, but since most of the reactions are exothermic reactions, the amount of heating is very small, so heating or removing the excess heat during the extrusion process is the key.
The twin screw extruder has these technical processes:
1. The material changes from glass to molten state during the extrusion process. In addition to stabilizing the heat and heat balance required for plasticization of the material and making the plasticization of the material reach the ideal state, melt pressure is also a very important control index. Taking into account the influence of the die resistance of the material and the compression ratio of each section of the screw during the extrusion process, there is no normal pressure phenomenon. For different die, the ratio of each section of the screw is basically balanced and stable, unchanged.
2. In the case of a certain extrusion speed, increase or decrease the feed rate, change the amount of spiral material in the feed section, and ensure that the amount of material in the discharge section remains unchanged, so that the feeding section and the compression section will change with the change of compression ratio. Increase or decrease the melt pressure, under the condition of a certain feeding speed, increase or decrease the extrusion speed; adjust the material capacity of the screw in the feeding section.
3. The material capacity on the exhaust pipe is constant, so the feed section and compression section increase or decrease with the change of the compression ratio, and the feed pressure also increases or decreases. Because the screw material capacity of the feed section is constant, the melt pressure is only caused by the increase or decrease of the speed.