Exploring the Different Types of Injection Molds
Are you looking to create an injection-molded product? Knowing the general types of injection molds can help you make an informed decision about your business. We’re breaking down each type of injection mold, helping you understand what’s right for your operation.
Types of Injection Molds
Hot Runner
Hot runner molds are designed to maintain the molten plastic at an elevated temperature as it flows through the mold. These molds offer advantages such as reduced material waste, faster cycle times, and decreased production costs associated with recycling runners. They’re also preferred because they produce parts with consistent quality and appearance.
However, hot runner molds are more complex and costly to design and maintain. They require expertise in temperature control and may be prone to issues like color contamination. Even so, they are preferred for high-volume production where material savings and efficiency outweigh the initial investment.
Insulated Runner
Insulated runner molds are a deviation of hot runner molds. These molds involve insulating materials to keep the runner system at a controlled temperature. This helps prevent premature solidification of the plastic in the runners, reducing material waste and improving cycle times. The insulated runners are designed to maintain the molten state of the plastic until it reaches the cavities, resulting in minimal waste.
Insulated runner molds offer fast cycle times, and potential cost savings due to decreased waste. However, these molds can be more complex to design and build, and they require precise temperature control to ensure consistent results. Despite these challenges, insulated runner molds are valuable for applications where material efficiency and reduced waste are crucial.
Cold Runner
Cold runner molds are just the opposite of hot runner molds. These runners solidify along with the plastic, resulting in waste material (the runners) that needs to be removed and recycled. Cold runner molds are more simple than hot runner molds, and offer a lower initial cost, along with enhanced ease of maintenance.
However, these molds may result in higher material costs and longer cycle times, as the removal of runners adds to the overall production process. Even so, cold runner molds are a cost-effective solution for many applications.
Single Cavity
Single cavity molds have one cavity into which plastic resin can be injected. Therefore, it produces a single product per cycle. Single cavity injection molds offer simplified design and lower production costs, making them ideal for small-scale manufacturing or prototyping. They also enable precise control over molding parameters and are suitable for complex part geometries. Single cavity molds are slower than some other mold options, but they’re great for creating intricate parts with high precision.
Multi-Cavity
Multi-cavity molds have multiple cavities into which plastic resin is injected. This allows for the mold to create multiple parts at one time. When many identical parts are needed within a set time frame, a multi-cavity mold is usually the best choice. However, a multi-cavity mold requires more upfront investment than a single-cavity mold. They require more lead time, as they take longer to create than single-cavity molds. Maintenance costs and risks will also be higher; if one cavity breaks or has a flaw, the entire mold may become unusable.
Two Plate
Two plate injection molds consist of a cavity plate and a core plate. The cavity plate holds the mold’s cavity, which shapes the final product. The core plate contains the mold’s core, which forms the inner features of the part. These molds are often simpler than other options, which can lead to lower initial costs.
However, two-plate molds may have longer cycle times and may not be suitable for parts with intricate geometries. Ejection mechanisms may also be more challenging to implement, which could impact part quality.
Three Plate
Three plate injection molds have a cavity plate, a core plate, and a runner plate. The runner plate separates the mold into two halves, allowing for more complex part geometries and efficient ejection. It’s easy to remove sprues, runners, and finished parts without the need for additional slides or side actions.
Three plate molds are best for intricate parts and can reduce the risk of part damage during ejection. However, they are more complex and expensive to manufacture and maintain compared to simpler molds.
Stack
Stack molds consist of multiple layers of plates that allow for the molding of different parts or layers simultaneously. These molds are best for complex parts that require different materials, colors, or textures in distinct layers. Using a stack mold can increase production efficiency and reduce cycle times, as multiple layers are formed in a single shot.
However, stack molds are technically intricate and often more expensive to design, build, and maintain. They also require precise control of material temperatures, injection pressures, and mold movements to ensure proper layer adhesion and quality.
Not Sure What Injection Mold is Right for You?
If you’re not sure what injection mold is right for you, it can be a good idea to reach out to a qualified injection molder for help. At SEA-LECT Plastics, our team can help you understand the best molds for your project. With over 30 years of experience, you can trust us to give you the most accurate, expert advice possible.
Founded in 1987, SEA-LECT Plastics is a premier provider of injection molding, injection molding tooling, and related services. With round-the-clock operations, a dedicated engineering team, and a global network of suppliers, we’re ready to take on your next project.
We prioritize high-quality products and strive to create an enjoyable customer experience. That’s why we maintain an ISO 9001:2015 certification and regularly invite auditors to validate quality in real-time production. We’ve also worked to create a turnkey manufacturing process, allowing us to streamline the process and ensure quality for our customers.
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