The plastic pelletizing machine is equipment that processes various thermoplastic plastic raw materials such as pellets and powders into plastic pellets through mixing, crushing, pelletizing and other processes. Its structural design and application of key technologies directly affect the pelletizing quality and production efficiency. This article mainly analyzes the structural design from three aspects: the transmission system, pelletizing system and control system of the pelletizer, and explores the key technologies of each part.

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  1. Transmission system

The transmission system mainly includes main motor, reducer, drive shaft, etc. Its reasonable design directly affects the stability of the whole equipment. The main motor mostly adopts variable frequency speed regulation three-phase asynchronous motor, and adjusts the speed of pelletizer by adjusting motor speed to control pelletizing process parameters. The reducer generally adopts worm gear reducer with high transmission efficiency and long service life. The drive shaft should adopt integral structure, which is beneficial to improve rigidity and reduce operation vibration. At the same time, the transmission ratio design of the transmission system should be determined according to the material properties and pelletizing process parameters.

  1. Pelletizing system

The pelletizing system is the core part of the whole pelletizer, which directly completes the mixing, crushing, melting and pelletizing of plastic raw materials. The pelletizing system mainly consists of hopper, pretreatment system, extrusion system and pelletizing system. The hopper adopts inclined hopper design for easy material addition; the pretreatment system makes the particle size uniform through pre-mixing and crushing; the extrusion system melts the pretreated raw materials into melt; the pelletizing system cuts the melt into pellets, and then carries out fixed cooling through water ring channel. The key technologies include material quantity detection and adaptive control technology for mixing system, intensive mixing technology for twin screw extrusion system, and PID parameter self-tuning technology for pelletizing system.

  1. Control system

The control system of the pelletizer adopts advanced PLC and human-machine touch screen to monitor and control the whole pelletizing process. By presetting the ideal pelletizing process parameters, closed-loop control of main motor speed, feeding amount and other parameters is realized to ensure stable pelletizing process. At the same time, the machine operation status including motor load, temperature, pressure and other parameters can also be monitored in real time through the human-machine interface. Once abnormality is found, the control system can intervene quickly to ensure equipment safety.

In summary, the structural design of plastic pelletizing machine should fully consider the pelletizing process flow, and reasonably select the structure and performance parameters of each component. At the same time, the use of advanced control systems and key technologies not only can improve the pelletizing quality, but also ensure stable and reliable operation of the equipment, which is an important means to achieve efficient and energy-saving pelletizing.