Injection molding is one of the most versatile plastic manufacturing methods in the world. With cost-effectiveness for high-volume production programs, a wide range of manufacturable materials, and numerous value-added operations to further enhance a product, it’s easy to see why injection molding is so widely used. 

The most important aspect of this manufacturing method is the molds themselves and for every production run, there’s going to be a different type of injection mold. Port Erie Plastics highlights how different types of injection molds work in projects and how your team can use this guide to identify what mold might be best for you. 

Cores 

Different types of injection molds are comprised of many parts that come together to form the final product that’s used during injection molding. The first place to start is with the core itself. 

Port Erie Plastics creates stack molds which feature multiple cavities and sets are stacked vertically in order to share a common hot manifold. Stack molds are more accurate in terms of shots per cycle, and it doesn’t require an increase in clamp tonnage. Customers that require a stack mold often are contracted in a high-volume program for items such as enclosures, lids, and containers. 

But there are other forms of cores as well. Another common form is a two-plate and three-plate mold. In a two-plate mold, there is just one parting line as the cavity and core halves separate to eject the part. These types of injection molds are commonly used for programs that have simple designs and prioritize cost-effectiveness above everything else. 

In a three-plate mold, instead of one parting line like a two-plate mold, there are two parting lines. The cavity and core have a middle plate that holds the runner and gate system. Three-plate molds are used where automatic runner separation is vital for program success.

Runners 

There are two types of runner systems used in the different types of injection molds. Hot runners, which Port Erie Plastics create, maintain a heated manifold that keeps the melted plastic within the runners. Plenty of high-volume production programs rely on hot runners as they keep cycle times low, lead to reduced scrap, and contain consistent shot filling balance of the melted plastic into the cavities. 

Opposite of hot runners are cold runners where the foundational difference is that the channel the melted plastic travels through to reach the cavities is unheated. The runners themselves are ejected along with the final injection molded component. Cold runners are often associated with heat-sensitive plastics and in low to medium production volumes. While they might be more cost-effective compared to hot runners, cold runners do lead to high material waste. 

Cavities 

The final main portion when discussing varying types of injection molds are cavities. There are two forms of cavities: single and multi. In a single cavity mold, there’s only part being created per injection. Single cavity molds support prototyping projects as well as low to medium volume amounts as they can account for design changes rather quickly. 

Multi-cavity molds feature multiple identical cavities that create anywhere from two to as high as 256 parts simultaneously. If your team is considering a multi-cavity mold, it is essential to check in with your manufacturer regarding clamping force to ensure proper shot filling into the cavity. 

Partner With Port Erie Plastics to Create the Different Types of Injection Molds Your Team Needs Today 

Port Erie Plastics is widely regarded as one of the premier plastic manufacturing companies in the country because of our wide range of capabilities. While we do perform numerous manufacturing methods, we got our start as an injection molding company and from custom projects to automated programs, we stay true to our foundation. 

Thanks to our in-house mold making, mold design, and transfer tooling operations, we are well versed in different types of injection molds. We can create single and multi-cavity molds, stack molds and hot runner molds all in our Harborcreek, Pennsylvania, facility. 

Whether you need a new mold or you are having problems with your existing tooling, Port Erie Plastics is the team for you. Contact us today to learn more about how we can create your mold and let’s take your project from concept to completion.