Because wear increases, the diameter of the barrel, if there is a certain of nitriding layer, can be boring, the barrel inner hole directly grinding to a new diameter size, and then according to the diameter of the new extruder screw.

The internal surface hardness of the cylinder is higher than that of the extruder screw, and its damage is later than that of the extruder screw.The scrap of the cylinder is the diameter of the inner diameter increased due to time wear.

The repair method is as follows:    

1, because wear increases, the diameter of the barrel, if there is a certain of nitriding layer, can be boring, the barrel inner hole directly grinding to a new diameter size, then click here to make new extruder screw diameter.    

2. The inner diameter of the cylinder is machined and re-cast alloy, and the thickness is between 1~2mm, and then finished to the size.

3、一般情况下机筒的均化段磨损较快，可将此段(取5~7D长)经镗孔修整，再配一个渗氮合金钢衬套，内孔直径参照挤出机螺杆直径，留在正常配合间隙，进行加工配制。

挤出机螺杆和机筒这两个重要零件，一个是细长的螺纹杆，一个是直径比较小而长的孔，它们的机械加工和热处理工艺都比较复杂，精度的保证都比较困难。所以，对这两个零件的磨损后是修复还是更换新件，一定要从经济角度全面分析。

如果修理费用比换新挤出机螺杆费用低些，就决定修，这不一定是正确的选择，修理费用与更新费用的比较，只是一个方面。

另外还要看修理费用与修理后使用挤出机螺杆时间与更新费用和更新挤出机螺杆使用时间的比值。采用比值小的方案才经济，是正确选择。