The Injection Molding Process: Design, Colors, and Materials

Injection molding allows manufacturers to customize parts with extreme precision. This includes design, shape, and color in a variety of materials that ultimately impact the function of the component. It’s also an efficient method for producing thousands or even millions of metal or plastic parts in succession.

To appreciate the design of components produced you must understand the basics of the injection molding process. The information below covers the materials used in injection molding and how companies design, shape, and color them. Keep reading to find out more.

Injection Molding Design Basics

Injection molding involves melting metal or plastic down. It is then injected through a sprue and a system of runners into the cavity and core of a mold, where it cools. It allows you to produce almost any size or shape in a component.

Two main reasons injection molding companies choose these processes are efficiency and low cost. Once you design and produce the molds, production costs are very low. The more items you produce the cheaper per-unit costs become.

The injection molding process also produces very little scrap. This is because metal or plastic remnants can be remelted and reused in the next process.


In theory, any material that you can melt down and will cool to a solid state is suitable for the injection molding process. The most common types are metals and plastics.

Steel and aluminum are typical products used in metal injection molding. It is ideal for making complex components that are resistant to corrosion.

It also produces hermetically-sealed parts that are perfect for secondary operations. These include machining, heat treatment, plating, and others.

There are dozens of thermoplastics used in injection molding. Common ones are acrylonitrile butadiene styrene (ABS), nylon, polyethylene, and polypropylene. Each offers distinct advantages in terms of cost, weight, flexibility, and other properties.


In plastic injection molding, you can add color to the finished products. You do this through one of several different methods.

Color compounding involves mixing a pigment into the plastic resin while it is being produced but before the molding process. This is one of the cheapest and easiest ways to add color, but it does have limitations in the ability to tweak color during molding.

Solvent coloring and dry pigment mixing involve spraying wet or powdered pigment on uncolored plastic pellets. This allows you to save money by using less dye since you are only coloring the outside of the plastic. But it can result in imprecise coloring if the right solvent vs. pigment ratio.

Master batching involves mixing densely pigmented pellets with uncolored ones. The downside to this process is that you cannot use colored pellets alone in the molding process. So, you must have both types on hand to achieve the desired color.

Like other molding processes, the range of coloring techniques allows you to select the one that is best for your product. A prominent injection molding company can further advise you on these options.

Learn More About The Injection Molding Process

Now that you have an idea of how the injection molding process works, you can decide if it is right for your business goals. It is a great way to optimize customization to create parts that look and function like you need them to.

Nova is a world-class producer of injection molded parts to both automotive and non-automotive industries. To meet our clients’ varied and unique product needs, we offer custom injection molding as well as secondary value-add manufacturing. Reach out to us today to learn more about our services or to schedule a free consultation.

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