The temperature rises at compression zone of the extrusion production
The problem of temperature rise in extrusion production has always been a common problem for designers of extruder screw and barrel.
The temperature rise block is roughly divided into three sections: feeding section, compression section, and metering section, based on the design of the screw.
Temperature rises in the compression section: Generally, the larger the outer diameter of the screw, the more obvious the temperature rise in the compression section, even to the extent that the temperature is out of control.
The temperature rise in the compression section can be roughly divided into several points
- The most common temperature rise situation in the compression section is that the compression ratio design is too large, which will lead to excessive compression of the plastic and generate frictional heat, so that the actual temperature is higher than the setting temperature.
- The screw is bent and deformed, resulting in frictional heat generated by the friction between the outer diameter of the screw and the barrel. In this situation, the higher the screw speed is, the more obvious the temperature rise is, and the slower the screw speed, the relative temperature rise will also ease.
- The temperature setting during extrusion is too low, which causes the plastic to generate frictional heat in the feeding section. This situation is most likely to occur in plastics with high friction coefficients or plastics with poor fluidity, especially plastics with carbon or metal added. Such as: conductive plastic, or LSHF plastic.
Although the temperature rise of the compression section is a difficult problem, with years of experience in the design and manufacture of screw and barrel, we are confident that the production temperature can be well controlled.
