Why does the extruder barrel screw produce noise?

The reasons about the extruder barrel screw produce noise
During the extrusion process, the screw of the extruder will make a sound when it rubs against the inner wall of the barrel. The reasons for this friction phenomenon are nothing more than the following four reasons:
　　一. The assembly gap between the extruder screw and its supporting drive shaft is too large, and the two shaft centers are not concentric when rotating, and the error is too large.
　　 2. The screw of the extruder is bent and deformed, and the straightness of the shaft center line is out of tolerance.
　　 3. The verticality between the end face of the extruder barrel and the base of the connecting flange and the center line of the barrel cannot be guaranteed, and the error is large.
　　4. The extruder screw is assembled in the extruder barrel, and the error of the concentricity of the two parts is large.

https://www.foamingscrew.com/