How to repair the damage of the plastic extruder barrel

Repair of the barrel

 The inner surface of the barrel is harder than the plastic extruder screw, and its damage is later than the plastic extruder screw. The scrapping of the barrel is such that the diameter of the inner diameter increases due to time wear.

Its repair method is as follows:

 1. The barrel with increased diameter due to wear. If there is a certain layer of nitrided, the inner hole of the barrel can be directly bored, ground to a new diameter, and then the new plastic extruder screw can be prepared according to the diameter.

 2. The inner diameter of the barrel is machined and trimmed to recast the alloy, the thickness is between 1"2mm and then finished to the size.

 3. Under normal circumstances, the homogenization section of the barrel wears faster. This section (take 5"7D long) is trimmed by the boring, and then a nitriding alloy steel bushing is used. The diameter of the inner hole is referenced to the screw of the plastic extruder. The diameter is left in the normal fit-gap for processing and preparation.


4. It is emphasized here that the two important parts of the plastic extruder screw and barrel are an elongated threaded rod and a small diameter and long hole. Their machining and heat treatment processes are complicated. The guarantee of accuracy is more difficult. Therefore, after the wear of these two parts is repaired or replaced with new ones, it must be comprehensively analyzed from an economic perspective. If the repair cost is lower than the screw cost of the new plastic extruder, it is decided that repair is not necessarily the correct choice. The comparison between the repair cost and the update cost is only one aspect. In addition, the cost of the repair and the ratio of the screw time and renewal cost of the plastic extruder to the renewal of the screw time of the plastic extruder are also observed. It is economical to adopt a scheme with a small ratio and is the right choice.

5, plastic extruder screw and barrel manufacturing materials

 6. Manufacture of plastic extruder screw and barrel. Currently, commonly used materials are 45, 40Cr and 38CrMoAlA.

7, imported plastic extruder shuliy material extruder screw and barrel manufacturing materials, commonly used alloy steel has 34CrAINi7 and CrMoV9. The yield strength of this material is about 900 MPa. After nitriding treatment, the hardness is above 1000 HV, which is both wear-resistant and has good corrosion resistance.