What are the common failures of the extruder?

First, screw wear: The normal wear and tear of the extruder screw and barrel mainly occur in the feeding area and metering area. This is primarily caused by dry friction between the sliced particles and metal surfaces when they warm up and soften. To reduce wear, special anti-wear and corrosion-resistant alloy can be used to repair local damage on the screw thread through techniques such as inert gas shielded welding, plasma argon arc welding, or metal spraying technology. The worn screw cylindrical surface should be ground first before surfacing an alloy layer with sufficient size to ensure that there is enough machining allowance for the extruder. Finally, both the cylindrical surface and threaded side of the screw should be ground to restore them to their original dimensions.

Second, abnormal noise: If abnormal noise occurs in the reducer, it may be due to bearing damage or poor lubrication. It could also result from gear wear caused by improper installation or adjustment, or poor meshing conditions. These issues can be resolved by replacing bearings for improved lubrication or replacing gears altogether while ensuring proper gear mesh condition through adjustments. In cases where a sharp scraping sound is heard from the extruder, it might indicate a skewed barrel position leading to possible scraping between shaft head and drive shaft sleeve; this can be rectified by adjusting the barrel accordingly. Additionally, if noise arises from a heat-resistant and wear-resistant extruder barrel, it could suggest a bent or swept screw combined with excessively low set temperature causing excessive friction with solid particles; this can be addressed by straightening out the screw or increasing set temperature.

Thirdly, abnormal vibration occurs in the extruder reducer due to bearing and gear wear, which can be resolved by replacing the worn bearings or gears. If it happens in the barrel, it is likely caused by the presence of hard foreign materials in the material. In this case, it is necessary to inspect the cleanliness of the extruder material and consider installing a strong magnetic device in the hopper for iron filings adsorption.

The overall standards for judging #extruder faults are relatively precise. It has been observed that a significant number of extruder failures result from inadequate daily maintenance or neglecting to carry out necessary overhauls. Therefore, targeted maintenance should be given top priority during everyday usage.