The injection molding machine cooling system lubricating oil needs to pay attention to the type of compressor when selecting. The compressor has three types: piston type, screw type and centrifugal type. The first two kinds of lubricating oil are in direct contact with the compressed refrigerant, and the lubricating oil should be considered. The problem of interaction between the refrigerant and the refrigerant. The lubricating oil used in the centrifugal injection molding machine cooling system is only used to lubricate the rotor bearings, and can also be selected according to the load and the speed.
The injection molding machine cooling system can also select lubricating oil according to the type of refrigerant, and the lubricating oil directly in contact with the refrigerant should consider the mutual influence between the two. For example, a refrigerant such as Freon can be dissolved in mineral oil. Therefore, the viscosity grade of the selected lubricating oil should be one level higher than that of the insoluble refrigerant to prevent lubrication of the injection molding machine cooling system from being diluted. In addition, it should be noted that a small amount of lubricating oil mixed into the refrigerant will not affect the operation of the cooling system of the injection molding machine. The flocculation point of the injection system cooling system oil is a quality indicator for checking whether the lubricating oil mixed in the refrigerant precipitates wax crystals and blocks the refrigeration system.
It is also necessary to pay attention to the evaporation temperature of the refrigerant in the injection molding machine cooling system. The cooling system of the injection molding machine with low evaporation temperature of the refrigerant should use the injection molding machine with low freezing point to cool the system oil, so as to avoid the refrigerant flowing into the cooling system of the injection molding machine. The lubricating oil in the system is condensed on the throttle valve and the evaporator, affecting the cooling efficiency. The cooling system of the injection molding machine using ammonia as the refrigerant should have a freezing point lower than the evaporation temperature and use Freon as the refrigerant. The condensation point of the lubricating oil can be slightly higher than the evaporation temperature.
Lubricating oil is selected according to the working conditions of the injection molding machine cooling system.
Of course, when choosing a lubricant, you need to choose the right lubricant according to the specific working conditions.