In order to repair the barrel screw, if the inner surface of the barrel is not severely worn or scratched, you can polish it on a lathe with oilstone or emery cloth.
The depth of the wear groove should be checked first. Calculate whether there is a heat-treated hard layer on the inner wall of the extruder barrel after the wear layer is removed, and trim the surface of the inner bole of the extruder barrel.
After grinding, the inner surface roughness Ra of the extruder barrel should not be greater than 1.6μm. The tolerance of the hole axis is calculated in the precision processing according to GB1184-80. For example, after repairing the mold, there is no heat-treated hard layer on the inner surface of the barrel. The alloy can be placed in the barrel.
It has features of wear resistance, long service life, high temperature resistance, no deformation under high temperature, corrosion resistance, good cutting performance, high strength, high torque and high speed resistance, and low residual stress and small thermal deformation after heat treatment, which is made of corrosive materials.
First, the granular or powdered plastic is added to the extruder barrel, and then the plastic is melted due to the rotation of the outer wall of the screw and barrel, and then the machine closes the mold and the injection seat moves forward so that the nozzle is close to the gate of the mold. Then the pressure oil is transferred to the injection cylinder, and the screw is advanced, so that the melt is injected into the closed mold with a lower temperature under high pressure, and the pressure is maintained at a faster speed (also called pressure maintenance), then the melt is cooled and solidified. We can open the product by opening the mold (the purpose of maintaining the pressure is to prevent the molten material from flowing back). Replenish the material into the cavity and ensure that the product has a certain density and dimensional tolerances.