The impact of cast aluminum electric heating plate on energy-saving and efficient production of extruder

The function of an extruder is to heat and melt solid plastic, then extrude and plasticize it through a screw, and send it to the next process. In this process, the heating system of the extruder is particularly important!
The heating system structure of the extruder is mostly composed of screws, barrel, heater, and exhaust system. As a part of the heating system structure of the extruder, the heater plays an important role in maintaining the production quality and efficiency of the extruded products.
In the development process of extruders, there have been four heating methods: carrier heating, resistance heating, electric induction heating, and infrared heating.
The heating method of using a heat carrier (such as steam, oil, etc.) as a heating medium is called heat carrier heating. Due to the different heat carriers used, they can be further divided into liquid heating and steam heating. The heating medium used for liquid heating is mineral oil below 200 ℃, and organic solvents or their mixtures are generally used above 200 ℃. The medium used for steam heating is steam.
Disadvantages: The heating system is required to be well sealed to avoid affecting the quality of the product due to liquid leakage; At the same time, a heating cycle device is also required, which increases the cost of the equipment; The heat carrier used (such as organic solvents) often exhibits toxicity and corrosiveness due to thermal decomposition; In addition, the maintenance of the device is also inconvenient, so it is currently rarely used.
Steam heating is difficult to maintain a certain value of pressure and has significant fluctuations. Its temperature is also difficult to meet the process requirements, and it also requires a set of specialized steam equipment, which is difficult for many factories to achieve and is therefore rarely used.
Resistance heating uses a resistance wire to heat the cylinder and then transfer heat to the material, and the cylinder is a cylinder with a certain thickness, thus forming a large temperature gradient in the radial direction of the cylinder, as shown in Figure 1. Additionally, heating with it also takes a longer time. At the same time, using mica sheets as insulation material for resistance heaters can shorten their lifespan due to the susceptibility of their resistance wires to oxidation and moisture. Due to the use of a large amount of mica sheets as insulation material, the cost of the heater is also high.