As we all know, the screw and barrel are two important […]
As we all know, the screw and barrel are two important parts of the plastic mechanical extruder. If it is damaged, it will affect the operation of the machine. What should we pay attention to when repairing?
The twisted screw should be considered according to the actual inner diameter of the barrel, and the outer diameter deviation of the new screw is given in accordance with the normal gap of the barrel.
After the surface of the thread with the reduced diameter of the wear screw is treated, the wear resistant alloy is thermally sprayed and then ground to size. This method is generally processed and repaired by a professional spray factory, and the cost is still relatively low.
A wear resistant alloy is deposited on the threaded portion of the wear screw. Build 1 to 2 mm thick according to the degree of screw wear, and then grind the screw to size. This wear-resistant alloy consists of materials such as C, Cr, Vi, Co, W and B, which increases the anti-wear and corrosion resistance of the screw. Professional surfacing plants have a high cost for this type of processing, and are rarely used except for special requirements.
The repair screw can also be plated with hard chrome. Chrome is also a wear-resistant and corrosion-resistant metal, but a hard chrome layer is more likely to fall off.
The inner surface of the barrel is harder than the screw, and its damage is later than the screw. The scrapping of the barrel is such that the diameter of the inner diameter increases due to time wear.