Discussion on lubrication of melt pump

　　In polymer processing, the bearing of melt pump generally adopts sliding bearing. The lubrication system of the sliding bearing is different from that of the common sliding bearing. Common sliding bearings have their own lubrication system and sealing system. Most of the lubricants for bearings are mineral lubricants, generally Newtonian fluids. The motion of the fluids conforms to the viscosity law of Newtonian fluids, that is, the shear stress is directly proportional to the shear strain rate.

　　In polymer processing, due to the lubricity of polymer melt itself and the limitation of pump structure, if special lubricating oil is used as lubricant, there may be the problem of contaminating the transported materials. Therefore, the bearing lubrication of general melt pump adopts self lubrication, that is, the polymer melt transported is introduced into the bearing through groove as lubricant, which is formed in the bearing The liquid film is used to carry the load, and the pressure difference of the pump and the rotation of the gear promote the continuous regeneration of the lubricating film. At present, the bearings of melt pump in polymer processing mostly use this self-lubricating.