How To Efficiently Control Plastic Injection Molding Parts

It’s possible to make some tweaks in an injection molding setup, but generally speaking, it’s much more difficult after a company has moved beyond the prototyping stage. In order to avoid issues further down the line, some simple tips in the prototyping stage can help ensure that parts and assembly processes are both efficient and the most cost-effective.

Simplifying Injection Molded Parts – Cosmetics and Extraneous Features

Undercuts are the most common issue when it comes to adding time and expense to a plastic injection molding project but are often considered necessary for a side action or sliding shutoff. However, there are alternatives that do not require manual mold insertion and may provide a similar effect in the shape of the part necessary.

Another problem when considering scale are finishes, logos and other so-called “cosmetic” features. They may be required, for example in military applications where parts must be labeled, but they should be kept to the bare minimum. Keep in mind, if the product the part is in becomes successful, then the cost of the finish and the extra time it takes could be multiplied by hundreds of thousands, if not millions, of parts.

Controlling Plastic Injection Molding Parts for Success – DFM, Self-Mating and Multi-Cavity Molds

Again, it’s all about simplicity. Design for Manufacturing is a process and strategy that focuses on maximizing efficiency and minimizing waste. Leveraging this process ensures not just that parts will come out without issues like warping or bubbling, but also that there are no ways of making the part more simply.

One example are so-called universal parts. Many injection molding projects involve parts that must snap together. Universal parts are ones where two parts form the end product but each component is created the same way by carefully designing the snaps. This is particularly important, say, in making the housing for a portable radio or a case for medical supplies.

Another strategy that’s common for molding housings is called a core cavity. The mold is actually in the center of the tooling and the polymer you are using is injected around it. Given the care required in terms of designing the gates and runners, this can be a crucial change in the molding process if your part requires long walls, as with containers.

Finally, where possible, multi-cavity molds are an obvious choice for high-volume production of smaller parts. Designing for use in these types of molds ensures that items like a medical testing kit can be made with all of the parts at once for rapid assembly at another point further in the manufacturing process. They also can help show potential issues if further scaling of part production is expected.

Metal-Safe Molds and Reusability

Looking at modifying the metal molds for injection molding of plastic parts is a lot like thinking about a haircut: you can always take away more later, if you need to, but it can be difficult, if not impossible, to try to add metal once the mold has always been created. The design principle “metal safe” incorporates this issue and working with the right plastic manufacturing company can help ensure that any future modifications will be able to be done on the existing tooling.

This is often performed as part of a design for manufacturing (DFM) analysis by engineers who are analyzing not just the part, but how the polymer will travel through the mold and cooling. They can also help find areas where a part’s feature cannot be created or other issues can arise. If different types of the part are necessary, being able to use similar metal tooling can save money as well. It can even help improve the assembly process by minimizing additional steps required to create the final product.

Contact Us Today

Echo Engineering has been in business for more than 50 years, helping companies of all sizes create the custom injection-molded plastic parts or find the appropriate off-the-shelf solution for a variety of sectors. With experience in finishing other types of materials ourselves and a variety of plastic options, we can leverage a breadth of institutional knowledge and determine the best manufacturing processes for your application.

If you’re interested in learning more about how to make your rubber seal project a success, get a custom quote. Our team will connect you with an experienced representative and an engineer to go over your specifications and technical requirements and find the perfect masking solution for your needs.

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