2023-10-17
The basic structure of a prototype injection mold consists of several components that work together to create the desired shape of a plastic part. Here are the key elements of a typical prototype injection mold:
Mold Base: This is the main framework of the mold, providing support and alignment for all other components. It is typically made of steel or aluminum and includes features such as guide pins, ejector pin holes, and cooling channels.
Cavity and Core: The mold cavity and core are the primary components that define the shape and features of the plastic part. The cavity forms the outer surface of the part, while the core creates the internal features. These components are usually made of hardened steel or other durable materials to withstand the injection molding process.
Sprue: The sprue is a channel through which molten plastic is injected into the mold. It connects the injection molding machine's nozzle to the mold cavity. The sprue can be designed as a single entry point or have multiple entry points, depending on the part's complexity.
Runner System: The runner system consists of channels that distribute the molten plastic from the sprue to the various cavities within the mold. It helps ensure consistent filling of the cavities and can be designed as a single runner or multiple runners, depending on the mold configuration.
Gates: Gates are small openings located at the end of the runner system, where the molten plastic enters the cavity. They control the flow rate and direction of the plastic, helping to prevent issues like air entrapment and part defects. Common gate types include sprue gates, edge gates, and hot runner gates.
Cooling System: The cooling system includes channels or passages within the mold that circulate cooling water or other fluids. It helps extract heat from the molten plastic, allowing it to solidify and shorten the cycle time. Proper cooling is crucial to achieve high-quality parts and maintain production efficiency.
Ejector System: The ejector system is responsible for removing the molded part from the mold once it has solidified. It typically consists of ejector pins or plates that push against the part's undercuts or ejector pin holes. The ejected part is then released from the mold and collected for further processing.
These are the fundamental components of a prototype injection mold. However, depending on the complexity of the part and specific requirements, additional features and mechanisms may be incorporated into the mold design, such as slides, lifters, inserts, and more.