Extrusion is too low, usually, is too low, that is, the amount of extrusion of the blown film extruder is too low per minute. In most cases, it is only necessary to increase the production of the screw speed. But increasing the screw speed is not suitable for all situations. So this problem is more meaningful in discussion. The main reason for excessive production is excessive extrusion resistance, which is usually made of wroch clogging and screw wear. The impurities accumulation of the filter makes the flow path flow to reduce the yield. This is equivalent to increasing the die back pressure. In addition, the back pressure increases causes the pressure reflow in the extruder to increase, and more melt strands in the extruder to do circulation. As mentioned above, this also results in elevated melt temperature. Replace the filter at this time. There are also other possible reasons, such as the filter over secret or pressure regulating valve in front of the die.
The screw wear is generally manifested as an increase in the gap between the screw and the cartridge, which can reduce the amount of extrusion from two aspects. On the one hand, the gap leakage is increased to reduce the total output. On the other hand, it reduces the shear of the cylinder of the solid bed and reduces the melting rate. Therefore, it is necessary to emphasize again, regularly check and record the screw wear. The reason why the resolution production is reduced is from the screen clogging or the screw wear, mainly watching the die pressure is increasing.
Extrusion is too low. It can be caused by other reasons. Raw materials, hardware, and process changes may lead to decline in extrusion. Regular examination of extrusion is a good habit. The amount of extrusion of four to five different speeds can be detected during measurement. The extrusion can be divided by the speed of the speed. A compost rate can be used as a comparison reference when modified.
