Ejector Pins and Ejector Pin Grease in Injection Molds Explained

Ejector Pin Grease for Plastic Molds

What are Ejector Pins in Injection Molds?

An ejector pin is a cylindrical part utilized in injection molding to extract the completed parts from the injection mold core. Typically constructed from steel alloy, ejector pins are designed to withstand high pressures and endure repetitive motion.

Located in the ejector plate of the mold/die, the ejector pin extends into the mold core and exerts force to remove the molded part when the mold opens. Ejector pins come in various sizes, shapes, and configurations to suit different mold designs and part shapes. Ejector pins for injection molds require accurate positioning and efficient operation are crucial for effective part ejection and optimal mold performance.

How many ejector pins are typically found in a mold?

The number of ejector pins greatly influences the quality of injection molded parts and the efficiency of production. Too few ejector pins can result in defects like voids and sink marks in the molded parts, thus lowering product quality. On the other hand, having too many ejector pins raises mold manufacturing costs and reduces injection molding production efficiency, possibly leading to slow machine operations or even jamming.

What are Typical Materials used for Ejector Pins in Molds?

Mold ejector pins are usually crafted from high-speed steel and are then heat-treated. The market offers a range of different grades.

These pins generally possess a hardness between 50 and 55 degrees and are subjected to surface hardening and nitriding processes.

Why Ejector Pin Grease is vital to Ejector Pin Longevity in Injection Mold?

Injection molding manufacturers should be aware of another important aspect. During the injection molding process, the ejector pin and the ejector pin hole experience friction. Without regular lubrication using ejector pin oil (such as Super Grease - 43911, the ejector pin can burn out or wear down. Furthermore, the ejector pin hole may wear and expand, resulting in burrs and impacting product quality or assembly.

At times, it's essential to address the burrs at the ejector pin location, and needle breakage might even happen, obstructing the seamless flow of production.

Hence, Ejector Pins and Ejector Pin Grease in Injection Molds Explained in injection molding manufacturers are advised to frequently and promptly apply ejector pin oil like Slide Super Grease for use on Ejector Pins on the ejector pins for lubrication and protection.