The wear of the barrel of the plastic extruder is mainly manifested as wear during use, which leads to an increase in the inner diameter of the barrel. Since the inner surface hardness of the barrel is higher than that of the screw, the barrel is damaged later than the screw. The following matters should be noted when repairing the barrel:

Due to wear, the barrel diameter becomes larger. If there is still a nitriding layer, the inner hole of the barrel can be directly bored and ground to obtain a new diameter size, and then a new screw can be processed according to the new diameter.

Through machining, the inner diameter of the barrel is trimmed and then alloy is poured. The thickness is controlled at 1~2mm, and then fine-machined to the new size.

In general, the barrel homogenization section wears faster than other positions. The boring of the homogenization section can be trimmed, and then equipped with a nitrided alloy steel bushing. The inner hole diameter refers to the screw diameter, leaving a normal matching clearance for processing and matching.

The materials used in the manufacture of screws and barrels.

At present, the commonly used materials for producing screws and barrels in my country are 45,40Cr and 38CrMoAlA, and the commonly used materials for producing screws and barrels for extruders are 34CrAINi7 and CrMoV9, and the material yield strength is about 900MPa. After nitriding treatment, it has good wear resistance, good corrosion resistance, and a hardness of more than 1000HV.

Plastic extruder manufacturers remind everyone that the extruder screw barrel is two important parts, one is a small diameter and long hole, and the other is a slender screw. Its machining and heat treatment processes are more complicated, and its accuracy is more difficult to guarantee. Repair or replace? It should be analyzed from an economic point of view. Determine the maintenance cost based on the maintenance cost compared with the cost of replacing the screw. This is an incomplete choice and can only be used as one aspect of evaluating whether to carry out maintenance. It is also necessary to consider the ratio between the maintenance cost and the use time of the screw after maintenance, the renewal cost, and the use time of the renewed screw. A small proportion plan is economical!