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Why Injection Mold Ejector Pins Need Two Greases

Proper greasing of leader pins, slides, gates and ejector pins is a necessity in order for molds to last and perform effectively and efficiently. However, there is a two-pronged solution to maximizing part quality while at the same maximizing the performance of pins.

Slide recommends using two different greases: one for the back 80% of the pin and one for the forward 20% of the pin.

The 80% on the back end of pins needs a grease that stands up to sudden temperature changes, will not run and has exceptional load bearing properties.

The forward 20% of the pin is critical as it is touching to the molded part. You don’t want marking or bleed-out to compromise part quality.

Here are the two idea greases we have found to handle the front and back of the pins.

One the back of the pin us Super Grease. Super Grease does not contain chlorinated solvents, is registered as NSF-H1, and is a NLGI #2 high temperature range grease that is colorless and odorless with excellent dielectric strength. Super has no silicones and will not bleed out. With operating temperatures ranging from -45°F to +650°F, Super Grease will not separate, run or fall out and has exceptional load-bearing properties. Thixotropic properties provide excellent mechanical stability when sudden temperature changes occur. A clear, clean, non-yellowing grease, Super Grease is ideal for injection molds, mold assemblies, leader pin assemblies, slides/gates, and especially medical and food grade plastic parts. It also repels water and prevents corrosion. Super Grease is can also be sprayed on to the back portion/stripper plate area during production runs to extend the molds service.

On the front of the pin use Heavy Duty Mold Release and Pin lube. Heavy Duty Mold Release and Pin Lube does NOT contain chlorinated solvents, is non-silicone, fully paintable, food-grade grease, with a maximum operating temperature of 450°F. An ideal grease for the front half of ejector pins (pins in forward position), this almost dry grease minimizes the possibility of leaching out onto molded parts. Heavy-Duty Mold Release and Pin Lube can be used on plastics, rubber, waxes, glass-filled nylon and similar materials.

Heavy Duty can be reapplied to the molding surface with the ejectors out in a manual position to re-grease the ejector areas without damaging the mold surface or affecting production parts. As an added bonus Heavy Duty will also work as a mold release to help you start back up.

Slide helps you select the right product for your application by giving you filters with specific product attributes. When you go to each product castegory on our web site you can select the specific attributes you need to help narrow your search.

For technical assistance call Slide Products at 1-800-323-6433, or email us at info@slideproducts.com.

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