As we all know, screw and barrel are two important plastic machinery extruder parts, if damaged, it will affect the operation of the machine, then maintenance, we need to pay attention to what matters?

1, twist the screw to be based on the actual diameter of the barrel to consider, according to the normal gap with the barrel to give the new screw diameter deviation manufacturing.

2, wear screw diameter reduced thread surface treated, thermal spray wear-resistant alloy, and then by grinding to size. This method generally have a professional spray factory processing repair, the cost is still relatively low.

3, in the threaded part of the wear-resistant wear-resistant alloy surfacing welding. According to the extent of the wear of the screw surfacing 1 ~ 2mm thick, and then grinding the screw to the size. This wear-resistant alloy of C, Cr, Vi, Co, W and B and other materials to increase the screw wear resistance and corrosion resistance. Professional welding plant on the high cost of such processing, in addition to the special requirements of the screw, generally rarely used.

4, repair screw can also be hard chrome plated surface method, chromium is also wear-resistant and corrosion-resistant metal, but the hard chromium layer is relatively easy to fall off.

The hardness of the inner surface of the barrel is higher than that of the screw, which is damaged later than the screw. Barrel scrap is the diameter diameter increases due to wear and tear. It fixes as follows:

1, due to wear and increase the diameter of the barrel, if there is a certain nitriding layer, the bore can be directly boring machine barrel, grinding to a new diameter size, and then press this diameter preparation of new screws.

2, the barrel diameter by machining trimming re-casting alloy, the thickness of 1 ~ 2mm, and then finishing to the size.

3, under normal circumstances, the homogenization section of the barrel wear faster, this section (take 5 ~ 7D long) by boring trimming, matched with a nitrided steel bushing, the hole diameter with reference to the screw diameter, leaving Normal with the gap, processing and preparation.

Here to emphasize that the screw and the barrel of these two important parts, one is the elongated screw rod, one is relatively small diameter and long holes, their machining and heat treatment processes are more complex, the accuracy of the guarantee will be compared difficult. Therefore, the wear and tear of these two parts after repair or replacement of new pieces, we must make a comprehensive analysis from an economic point of view. If the repair cost is lower than the cost of replacing a new screw, it is not necessarily the right choice to fix it. A comparison of repairs and refreshes is only one aspect. Also depends on the cost of repairs and repairs using the screw time and update the cost and update the ratio of screw life. It is the most economical and correct choice to adopt a less cost-effective solution