The cause of friction between the screw and the barrel may be the result of one or more of the following joint actions:
1)Screw bending deformation.
1.1.The temperature of the plasticizing raw material is low and the working load of the screw rotation is too large. The temperature of the plasticized raw material should be increased and the screw straightened.
1.2. improper choice of screw steel manufacturing, so that the screw deformation. Should replace the screw, choose alloy steel or 40Cr steel manufacturing.
1.3 screw machining process is not appropriate, a large deformation of its heat treatment. Should be coin-operated screw processing technology.
1.4 There are hard foreign materials in the raw materials, and the working torque of the screw is too large. The screw should be disassembled to remove foreign matter from the barrel.
2) Machine accuracy is poor.
The accuracy tolerance of the concentricity between the inner circle of the inner circle and the inner hole is too large, and the flatness, roundness or surface coarseness does not meet the accuracy requirement. The barrel should be remanufactured and new parts replaced.
3) Improper assembly.
3.1 The clearance between the screw and the drive shaft is too large and the h7/h6 fit should be used.
3.2 If the assembly of the cylinder and the cylinder holder is improper and the concentricity error is too large, the center line of the screw and the cylinder is not on the same axis after the assembly of the screw, causing friction between the two. The manufacturing precision of the two parts should be improved and reassembled.