Ejector Pin Lubrication Procedure

The right steps to ensure maximum productivity without marking parts

Lubricating ejector pins is essential to preserve the life of an injection molding tool. The wrong procedure and the wrong lubricant can cause problems and even damage a tool. Problems, such as bleed out onto the tool surface, can cause defective plastic parts. Thermal and viscosity breakdown can cause galling, seizing, and pitting. All these issues can be resolved utilizing the proper procedure and the right lubricants.

New Assemblies and Preventive Maintenance Assemblies

Lubricate the back 85% of the ejector pin with a high load bearing, high temperature grease, such as Slide Super Grease (No. 43900.) Then lubricate the remaining front 15% of the pin with a clear, non-marking lubricant, such as Slide Heavy Duty Pin Lube (No. 54912.) Spray additional non-marking, clear lubricant in the sleeve of the pin. Now install the pin.

Additional Lubrication

Periodically, additional lubrication must be applied to the front section of the pins. Set your ejector pin selection to manual and move the pins to the out or eject mode. Spray the front of the pins with lubricant, then turn your machine back to auto and continue to make parts. This lubrication will need to be performed at least once a week. High-speed molds may require lubrication before every shift.

For additional lubrication behind the mold, such as on the ejector plate, use a high load bearing, high temperature aerosol lubricant, such as Slide Super Grease aerosol (No. 43911.)

What Does This Procedure Do For You

This procedure prevents a grease product from lubricating the front section of your pins, which can bleed out during a run. The grease bleed-out can result from destabilization caused by a mold cleaner, rust preventive, or high temperatures breaking down the grease. A dry film lubricant placed on the front section of your pins minimizes the chances of a bleed out. If a mold cleaner or rust preventive breaks down the pin lubrication, just reapply as stated in the Additional Lubrication section. High temperatures will usually have no affect on dry film lubricants as their formulation makes them more stable at those temperatures.