Properly Using Ejector Pins on Injection Molding Parts
Ejector pins are used in injection mold setups to eject components. They can also cause marks on the part they eject.At TEAM MFG, we strive to design and position the pins to minimize their effect on the part they are designed to eject. The pins are located in the B-side of the mold. When the mold opens, they extend into the cavity and retract, allowing the part to close and be refilled.
Considerations Of Setting Ejector Pins on Injection Mold Parts
The shape of the part and the placement of the ejector pins are some of the factors that determine the proper placement of them. Other factors such as the shape of the part and the depth of the walls and ribs can also affect the likelihood that the part will cling to the mold.Softer resins may also require the use of more or wider pins to spread force and prevent puncturing or marring of the cooled plastic.
The end of an ejector pin should be flat and perpendicular to the part's direction when it's pushed against. A flat pad should be used to support the pin's body. The part's surface should also have a smooth surface to prevent the pin from hitting it.If the part's surface is smooth, the smooth texture will appear on the part's surface when the ejector pin is pushed against it. A traditional steel injection molding tool can also be used to match the shape of the part surface to the desired end point.
Although TEAM MFG can produce standard and customized pins, they cannot support the creation of contoured ones unless a customer requests it. If the pin is not parallel to the part surface, then the pad should be positioned in the same plane as the pin-end. Since the part surface is different than the pin's end, the pad should be raised slightly above or below the part surface. A standard configuration is a center-cut pin. It should hit the part's surface with the least amount of force possible. Aside from the standard center cut, TEAM MFG also has the option to produce pins with a standing pad or a fully indenting pin. The latter allows the pin to be positioned on the part's surface without exposing too much of the plastic. Having a long pin makes it less prone to hitting the part's back. A long pin should be fully indentified to prevent it from hitting the part's surface. Also, make sure it doesn't have a hole in it since a short shot or a punching pin can easily create one. Contact our experts to discuss the various aspects of designing an ejector pin and the location of its body.
Sometimes, the presence of ejector pads on the non-cosmetic sides of a part can be challenging to achieve. For instance, when a clip is formed using a pass-through core, its surface will increase the area of the part that it fits on. This design feature will make the part more uniform. For instance, a clip that's formed using a pass-through core can increase the surface area of a part that it fits on. This design feature will make the part's surface more durable. Since an ejector pad should be on the other side of the part, it should also be positioned on the B-side of the part. In addition, ejector pins are also sometimes used to help vent deep features in a mold to prevent gas trap at the end of fill.
Design with Limited Surface Area
Most of the time, the shapes assume that the parts that are pushed against the mold have surfaces that can eject the pins. However, there are cases where the parts are not pushed against the surface. In these cases, the designer would need to create an ejector pad using a couple of bosses. For instance, a part made of liquid silicone rubber would not have enough surface area to support an ejector pin.
During the early stages of a part's design, TEAM MFG can usually come up with a plan on how to place the ejector pins. This step can be carried out once the customer has ordered a part. During the course of the inquiry, TEAM MFG can discuss with the customer's requirements and make changes if necessary. Contact us Today!
