Summary of optimization of PVC extrusion production process

In fact, after years of development in my country's extruder manufacturing industry, both the screw configuration pressure configuration and the outer heating ring power configuration have provided conditions for good and balanced plasticization of PVC-U plastics. Practice has proved that it can completely solve the problem of the directional thinking that most people think that the extrusion process should be compatible with the extruder. No matter what the specifications and shear performance of the conical twin screw extruder, the amount of extrusion is.

Zhangjiagang Huade Machinery， as one of the professional China pvc profile extrusion line manufacturers , would like to give summary of optimization of PVC extrusion production process.

4.1. Feed section temperature:  A lot of practice has proved that, under the premise that the feeding, extrusion speed and the setting temperature of the metering section are unchanged, appropriately increasing the setting temperature of the feed section can effectively reduce the temperature difference between the display temperature of the metering section and the set temperature, which fully explains The temperature of the feed section plays a role in adjusting the shear heat to a certain extent.

4. 2. Temperature in the compression section: The material enters the compression section where the shearing effect is greater, and the temperature rises faster under the action of the screw shearing force. Setting the temperature higher will help reduce the viscosity of the material and speed up the fluidity. Like the feeding section, it can reduce the harm of shear heat.

4. 3. Melting section temperature: The material in the melting section basically melts. Due to the change of the screw groove volume (generally the compression ratio is less than 1), the melting pressure is suddenly reduced, and it can play the role of full constant temperature and exhaust. Keeping the set temperature and the compression section consistent or slightly higher helps to prevent the melt from cooling down, and the melt temperature will also show a downward trend due to the decrease in melt pressure.

4. 4 Measuring section temperature: The temperature displayed in the measuring section is not the material temperature. Only the temperature of the material transferred to the screw cylinder under the action of shear heat, the temperature of the material is often higher than the displayed temperature. The purpose of setting the temperature is not to provide external heat, but mainly to stop the external heating in time, and use the proper adjustment of the screw cooling device and the temperature of the screw oil to transfer excess heat and prevent material decomposition.

5. 5 Confluence core and extrusion die temperature: The melt enters the confluence core and is completely in the state of the melt, and begins to change from the spiral movement of variable speed and pressure transformation to uniform linear movement, and the melt pressure is established through the die, so that The temperature, viscosity and flow speed are more uniform, making the final preparation for product molding. Due to the change of the direction of movement, the establishment of melt pressure requires the sacrifice of a certain amount of energy. At the same time, the internal heat generated by shearing in this area no longer exists. Therefore, the temperature setting should be higher to slow down the heat loss of the material.

If you encounter any problems about anything, please feel free to send us inquiry and we, as China pvc profile extrusion line manufacturer, will do our best to assist you to solve the issue.