Views: 52 Author: Site Editor Publish Time: 2022-05-17 Origin: Site
The application of frequency inverters to plastic extruders has the advantages of reducing production energy consumption, improving productivity and product quality, and reducing the impact on the power grid during startup.
The main extruder is composed of extrusion system, transmission system and heating and cooling system.
The transmission part usually consists of a motor, a reduction box and a bearing. In the process of extrusion, the screw speed must be stable and cannot change with the change of screw load, so as to keep the quality of the obtained products uniform. However, in different occasions, the screw is required to be variable speed, so as to achieve the requirement that one equipment can extrude different plastics or different products. Therefore, this part generally adopts AC commutator motor, DC motor and other devices to achieve stepless speed change, and the general screw speed is 10~100 rpm.
Multiple input signal channels, accept analog signals from sensor voltage, current, pulse, etc. And multi-speed, forward and reverse jog and 485 communication direct given frequency. The process requirements of the plastic extruder are mainly to control the pressure at the outlet to be constant. When the equipment first starts to work, the speed is manually controlled, and when the required pressure is reached, it is immediately switched to pressure control.
The special chip DSP for motor control is adopted, which has excellent dynamic response performance and high motor operation efficiency. The traditional extruder motor adopts electromagnetic speed regulation control, which has low speed regulation precision and low motor operation efficiency, which often results in waste of motor energy.
Using advanced speed sensorless vector control technology, the output torque is stable, the motor speed fluctuation rate is small, the speed stabilization accuracy is high (±0.5%), and the motor runs smoothly, ensuring the uniform extrusion of plastics and reducing material loss.
The low-frequency output torque is large, and the torque output of 0.3HZ/150% can be maintained to ensure the balanced discharge of plastics and efficient plastic molding during low-speed extrusion. The traditional speed regulation method may cause uneven discharge due to insufficient output torque, plastic cannot be formed, and there are many waste products.