As we all know, the screw and barrel is the plastic machinery extruder two important parts, if damaged, it will affect the operation of the machine, then the maintenance time, we need to pay attention to what matters?
1, the screw is broken according to 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, the wear screw diameter reduced thread surface after treatment, thermal spray wear-resistant alloy, and then by grinding to the size of this method is generally a professional spray processing plant repair, the cost is still relatively low.
3, wear the wear part of the wear part of the wear screw welding alloy. According to the degree of screw wear surfacing 1 ~ 2mm thick, and then grinding the screw to the size of this wear-resistant alloy from the C, Cr, Vi, Co, W and B and other materials to increase the anti-wear and corrosion resistance of the screw.Professional welding plant for this high cost of processing, in addition to the special requirements of the screw, generally rarely used.
4, repair the screw can also be used on the surface hard chrome plating method, chromium is also wear-resistant and corrosion-resistant metal, but the hard chrome layer is easier to fall off.
The inner surface hardness of the barrel is higher than that of the screw, and its damage is much worse than that of the screw. The scrapping of the barrel is the increase in the diameter of the inner diameter due to time wear.
1, due to wear and increase the diameter of the barrel, if there is a certain nitriding layer, the barrel can be directly under the hole boring, grinding to a new diameter size, and then press the diameter of the new screw.
2, barrel diameter by machining the re-cast alloy, the thickness of 1 ~ 2mm, and then finishing to the size.
3, under normal circumstances the homogenization of the barrel wear faster, can this paragraph (take 5 ~ 7D long) by boring finishing, matched with a nitriding alloy steel bushing, bore diameter reference screw diameter, stay Normal with the gap, the preparation of processing.
It is emphasized that the two important parts of the screw and the barrel are one of the elongated threaded rods, one of which is smaller and longer in diameter, and their machining and heat treatment processes are more complex and the precision guarantees Therefore, the repair of these two parts is to repair or replace the new pieces, we must from the economic point of view a comprehensive analysis.If the repair costs than the replacement of new screw costs lower, decided to repair, this is not necessarily the right choice, The cost of repairs and the cost of the update is only one aspect, and the ratio of the repair costs to the use of the screw time and the cost of the replacement and the time to update the screw. The smaller cost ratio is the most economical and correct select.