Ejector Pin

Bouncers for injection molding, ejector pins are used to remove molds from the mold cavity. When used to eject a component from a mold, these tools can be powerful enough to leave visible scars. Round ejector pins are used by Protolabs, and where they are placed is determined by a variety of variables. Some sections of the part may stick to the mold due to factors such as draft, texture of sidewalls, depth of walls, and ribs. Pin size and placement can be modified depending on the resin used. However, some resins are "stickier," meaning they need more force to be removed from the mold. 

Injection molding requires the employment of long pins called ejector pins to expel the finished product from the mold. They are typically composed of high-quality steel and are used to aggressively remove the solid object from the mold. Knockout pins (or KO pins) also go by the name knockout pins. These pins are the most cost-effective ejection method since they may be extended and retracted to force the part out of the mold. Pins may leave markings, thus they are often inserted after the pieces have cooled down to prevent distortion. Shapes and sizes of ejector pins range from round to bevel-headed to straight to cylindrical.

 There are three types of ejector pins:

• Through Hard Pins: The ejector pins used in through hard designs are consistently hard over their whole diameter. Because of this quality, the ejector pin may function effectively at temperatures well below 200 degrees Celsius for significantly longer periods of time.

• Nitride H13 Pins: Nitride H13 pins are the superior option for use in environments when the temperature exceeds 200 degrees Celsius.

• Black Ejector Pins: These pins can withstand temperatures in the workplace up to a thousand degrees Celsius thanks to a specific black surface coating treatment applied to the entire pin.