What is Custom Injection Molding?

Custom injection molding is the fabrication of plastic components using customized design specifications. This service is offered by many manufacturers of plastics. The pricing varies, depending on the type of project involved, but generally custom injection molding is more expensive than using standardized components. People can present manufacturers with their specifications and the number of components they need to get a pricing estimate.

In injection molding, heated plastics are shot into a mold. As the plastic cools, it conforms to the shape of the mold and sets in place. The molds can be opened to release the components and they can be finished with trimming, sanding, and other measures if necessary. Injection molding is a very cost effective way for making plastic components, as molds can be easily swapped out as needed and people can produce plastics in different colors and with other characteristics by adjusting the mixture used in the injectors.

For custom injection molding, a mold is fabricated for a specific purpose, like encasing a given car part. The customer also specifies the characteristics of the plastic, including the level of hardness and flexibility, heat and cold tolerance, and color. A mockup will be made with the mold to make sure it works, and then the plastics company can start a production run, limiting the run to the number of components necessary. Usually, custom injection molding gets cheaper with large runs, as the cost for producing the mold and formulating the plastic is the same with one part or one million parts.

Once the custom injection molding is finished, the mold can be put in storage in case there's a future need. It can also be returned to the client in some circumstances, and in others may be destroyed. People can discuss what they want to happen with the mold during the initial consultation with the manufacturer. One advantage to keeping molds on file at the manufacturer with notes about the formulation used is the ability to easily generate new parts for replacements and repairs.

As with other custom fabrication jobs, it is advisable to consult several manufacturers to get price estimates on custom injection molding. It can also be helpful to seek out manufacturers specializing in similar kinds of plastics products, as they can be less expensive and may produce pieces of higher quality because they are familiar with the work. Someone who wants custom toys, for example, might not go to a manufacturer who focuses on producing plastic parts for medical equipment.