Screws coated with anti-rust oil?

Why should the surface of the screw and barrel of the composite bubble film machine be coated with anti-rust oil?
The bubble film produced by the composite bubble film machine is made of high-quality polyethylene resin. It is a pressure-proof, moisture-proof and shock-proof chemical product used for packaging and filling, and is widely used in the logistics industry.

Air-bubble film machines should be regularly overhauled. Air-cushion film machines should be thoroughly cleaned every three months, grease should be replaced every three months for various bearings, lubricating oil should be replaced every six months for the reducer, and equipment should be replaced every two years. Perform an overhaul as a whole. Check whether the temperature automatic control of the bubble film machine is intact, whether the heating device is intact, and whether the temperature of each point is within the range of indicators to ensure the normal operation of the machine.

The screw of the bubble film machine is taken out of the barrel for some reason. It should be properly handled to prevent deformation. If it is not installed back into the barrel for a long time, the screw must be hung vertically to prevent bumps, bending and permanent deformation. The surface of the barrel and screw are coated with anti-rust oil for protection. When feeding the air bubble film machine in the hopper, it must be clean and prevent metal debris, sand and small tools from entering the material port to prevent damage to the barrel and screw. If abnormal noise is found during operation, it should be stopped immediately for treatment.

When the surface of the screw and barrel of the composite bubble film machine is coated with anti-rust oil, it is usually the above conditions