Plastic extruder barrel wear repair methods and matters needing attention
The cylinder wear of plastic extrusion machine is mainly manifested in the wear of the process, resulting in the increase of the inner diameter of the barrel. The barrel is more damaged than the screw because the internal surface hardness is higher than that of the screw, and the damage of the cylinder is later than the screw. Cylinder repair methods and repair process should pay attention to the following as follows:
1. The diameter of the barrel is increased due to wear. If there is a certain nitriding layer, the inner hole of the barrel can be directly bore and milled, and the new diameter size can be obtained, and then the new screw can be prepared according to the new diameter.
2. Through machining, the inner diameter of the barrel is re casted by dressing, the thickness is controlled between 1~2mm, and then finish machining to the necessary new size.
3, usually barrel are wear than the other position can be fast, homogeneous section boring dressing, matched with a nitriding alloy steel bushing, the inner hole diameter according to the screw diameter in normal clearance, processing and preparation.
4, screw and barrel manufacturing materials
At present, the domestic manufacturing screw and barrel material, 45, 40Cr and 38CrMoAlA, material imported extrusion screw and barrel machine, 34CrAINi7 and CrMoV9 commonly used alloy steel, yield strength of the material is about 900MPa. After nitriding treatment, both wear resistance and good corrosion resistance, hardness of more than 1000HV.