What Is a Straight Core Pin?
A straight core pin is a specialized metal fitting used in the plastic injection molding process to create precise, straight features in molded products. It allows for the incorporation of straight holes or protrusions in a mold, which is challenging to achieve through standard cutting methods due to complexity and precision requirements. Straight core pins are vital for creating straight holes, while other shapes of core pins, like tapered ones, are used for different configurations.
Uses of Straight Core Pins
These pins are primarily used to form holes or slots in plastic products for various functional needs such as rotary shafts, bearing holes, and threaded holes. They also serve in reducing product weight, creating venting holes, and aiding in gas release during the molding process. Straight core pins are particularly beneficial in molding intricate components like electronic parts, where they facilitate efficient gas venting without altering the minute geometrical features.
Principle of Straight Core Pins
In molding applications, straight core pins are installed in the mold’s core or cavity. Their effectiveness depends on the mold’s design and the pin’s placement. During resin injection, the pins need to withstand the pressure without bending or misaligning. For through-hole designs, the hole’s length should typically be less than twice the pin’s diameter to maintain stability. In scenarios where extended hole lengths are needed, additional support on either side of the mold can be provided.
While hole creation with straight core pins is often necessary for the product’s function, it can present challenges like reduced structural strength, the potential for weld lines or other surface defects, and increased mold-making costs. Therefore, careful design considerations, including appropriate hole spacing and structure, are crucial to mitigate these issues and ensure product quality.