Plastic Sheet Production Line Control System
Plastic Sheet Production Line control system
The control system of the Plastic Sheet Production Line includes heating system, cooling system and process parameter measuring system, which mainly consists of electrical appliances, instruments and actuators (ie control panel and console). Its main role is: to control and adjust the main and auxiliary motor drag motor, output process in line with the requirements of the speed and power, and can make the main and auxiliary machine coordination; detection and adjustment of Plastic Sheet Production Line of plastic temperature, pressure, Control of the entire unit or automatic control.
The electrical control of the extruder is roughly divided into two parts: drive control and temperature control. The extrusion process includes temperature, pressure, screw rotation, screw cooling, barrel cooling, product cooling and outside diameter control, and traction speed , Neat rows of cable and to ensure that the reel from the empty disk to full disk constant tension control.
1. Plastic Sheet Production Line host temperature control
Wire and cable insulation and sheath plastic extrusion is based on thermoplastic deformation characteristics, so that in the viscous flow state. In addition to the requirements of the screw and barrel external heating, spread to the plastic melt to squeeze out, but also consider the screw extrusion plastic itself when the heat, so the host temperature should be considered from the whole, it is necessary to consider the heater heating open and Off, but also consider the screw out of the heat spill the factors to be cooled, there must be effective cooling facilities. And requires the correct and reasonable determination of the location of the measurement element thermocouple and installation methods, from the temperature meter readings accurately reflect the actual temperature of each section of the host. As well as the requirements of temperature control instrument with the accuracy of the system, so that the entire host temperature control system to achieve a variety of fluctuations in the stability of the extrusion temperature of plastic requirements.
2. Pressure control of Plastic Sheet Production Line
In order to reflect the extrusion of the nose, the need to detect the extrusion head pressure, because the domestic Plastic Sheet Production Line without the head pressure sensor, the screw is generally measured after the thrust of the measurement of alternative head pressure measurement, screw load meter (Ammeter or voltmeter) can correctly reflect the size of the extrusion pressure. The fluctuation of the extrusion pressure is also one of the important factors that cause the instability of the extrusion. The fluctuation of the extrusion pressure is closely related to the extrusion temperature, the use of the cooling device, the length of the continuous operation time. When the abnormal phenomenon, can be ruled out the rapid elimination of the need to reorganize the production should be decisive downtime, not only can avoid the increase in waste, more to prevent the occurrence of the accident. Through the detection of the pressure gauge readings, you can know the pressure of the plastic extrusion state, the general limit to take the rear limit alarm control.
3. Screw speed control
Plastic Sheet Production Line Screw speed adjustment and stability of the host drive is one of the important technical requirements. Screw speed directly determine the amount of glue and extrusion speed, the normal production of the total hope that as far as possible to achieve the highest speed and achieve high yield, the demand for screw production line from the start to the required working speed, the available speed range The And the stability of the speed requirements are high, because the speed of the fluctuations will lead to fluctuations in the amount of extrusion, affecting the extrusion quality, so the traction line speed without change, it will cause the cable diameter changes. Similarly, such as traction device line speed fluctuations will also cause changes in cable diameter, screw and traction line speed can be reflected through the corresponding instrument on the console, extrusion should be closely observed to ensure high quality and high yield.
4. Outside diameter control
As mentioned above in order to ensure the size of the product cable diameter, in addition to the requirements of the control core (cable core) dimensional tolerances, the extrusion temperature, screw speed, traction line speed and other aspects should be controlled to ensure that the outer diameter Of the measurement control is a comprehensive reflection of the control of the accuracy and level. In the Plastic Sheet Production Line group equipment, especially the high-speed extrusion production line, should be equipped with on-line diameter detector, at any time to detect the outer diameter of the cable, and the error signal feedback to adjust the traction or screw speed, Diameter difference.