SZ vacuum pump for air-exhausting of the extruder: SZ vacuum pump is used to draw air bubble and wet air in the melting plastic and all of low molecule matter such as solvent, mixture, reactant and residue etc. The purpose is to get the best shaping quality to: Make the surface more fine; Make the elasticity more strong; Improve the isolated performance; Low the air overflow rate in the later procedure. It is a quite important link to remove the air efficiently in the plastics forming procedure. To remove the air bubble and wet air from melting plastics in extruding stage conveniently, it's better to remove air from the single-screw extruder. As to double-screw extruder, this link can't be shorted of. SZ vacuum pump for the extruder of plastics. SZ vacuum pump which being widely used in the extruder of plastics not only increase the quality of the plastic manufactures, but also improve the environment outside and bring safer protection to the operator. When in extruding stage, it reliable to reliable to realize vacuum air exhausting. And when in forming stage, it ensure the accurate alignment between the section and the mould and keep the forming dimension precision. SZ vacuum pump for forming machine. SZ vacuum takes an important role to ensure the dimension precision of forming of the molding material in the forming machine. Soft plastic moding material will gradually cool and turn to hard during the forming time. In every stage, different vacuum degree can ensure the plastic material to form by keeping close to internal surface of the mould accurately. At the same time it keeps the dimension precision after forming. SZ vacuum pump can keep a stable vacuum degree during running and draw the leaking air. SZ-3A model can also draw the cooling water being absorbed. For these advantages SZ vacuum pump is widely used in plastic industry. So using SZ vacuum pump is undoubtedly a wise selection. Working principle: The impeller is eccentrically installed on the pump housing, and the water-ring of eccentric impeller is formed as it revolves. The water, flowing among the vanes, makes continuous, cycling and reciprocating motion. It will change water volume among the vanes and complete the course of air-breathing, compressing and exhausting under the common of the fixed air entry and vent.