Rapid Injection Molding

Rapid injection molding is a manufacturing process that uses a combination of rapid CNC technologies and traditional injection molding to produce low-volume production runs of plastic parts, quickly and cost-effectively. It is often used as an alternative to traditional injection molding methods, which can be expensive and time-consuming due to the need to create steel molds.

In rapid injection molding, aluminum molds are used instead of steel molds. Aluminum molds can be manufactured more quickly and at a lower cost than steel molds, which helps to reduce the up-front cost and lead time of the production process. Rapid injection molding can produce parts in as little as 15 days, with part quantities ranging from 50 to 10,000 units. There are a wide range of materials suitable for injection molding, including ABS, polycarbonate, nylon, and more. In addition, aluminum molds can be modified more easily than steel molds, allowing for faster design iterations and changes.

Typically rapid injection molding is used to produce prototype plastic parts before manufacturing with traditional injection mold steel tooling. However, there are many applications beyond just prototyping!

Often in manufacturing lines it is critical to hold parts in a particular way, whether it is for transporting finished parts, holding the parts during fabrication, or holding parts during inspection. In many cases these part fixtures need to be cleaned or disposed of when finished, which requires large quantities. With rapid injection molding it is possible to create large quantities of custom part holding fixtures at a low cost, and continuously order more with short lead times.

As a custom equipment designer, this offers a low cost option and a high degree of functional flexibility. For example, fixture parts can be produced with durable material, like glass filled nylon, and incorporate custom features, such as threading to mate with tooling like lead screws (photo above). Parts can also include over-molded parts, snap features, alignment features, etc. to help with the product fabrication process. When compared to producing thousands of similar custom parts from steel or aluminum, rapid injection molding can offer significant cost savings.

Additionally, rapid injection molding can be used to produce actual consumer products! It is particularly useful for startups, as it allows companies to quickly produce small quantities of parts without having to invest in expensive steel tooling. Businesses can benefit from holding lower inventories and quick lead time to fill orders.

There are certain things to consider when deciding if rapid injection molding is the right process for the application.  Some of the main considerations are as follows.

In summary, rapid injection molding can be a valuable tool for projects that require quickly producing functional prototypes, or low to medium volume runs of plastic tooling or holding parts. The process is a good fit for volumes somewhere between custom CNC metal parts, and traditional injection molding methods. Engineers should add rapid injection molding to their box of design tools!

If you enjoyed this content, hit the subscribe button below so you never miss a post. It's free!