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How Injection Molding Works

Alyssa Mertes

Published: May 11th, 2020

Have you ever wondered: "How are promotional products made?" You might have a scientific mind or maybe you're just curious about your custom items. Either way, we're here to give you all the details about one of our favorite processes: injection molding.

But what is injection molding? Injection molding is the shaping of rubber or plastic articles by injecting heated material into a mold. It's time to dive into the injection molding process and how it's used to create your fabulous promos!

How Does Injection Molding Work?

If you'd like to truly understand the injection molding process, you'll need to become familiar with the hopper. No, we don't mean Dennis Hopper (the guy your dad really liked in the movie Easy Rider). We actually mean the hopper used for injection molding.


Small pellets are inserted into the hopper where they are filtered through and mixed with color dye. These colorful pellets are pushed into a heated barrel, melting them down into a moldable goo. The goo is then injected into molds the shape of your promotional products and cooled to harden. And voilà, you're left with a beautiful promotional product to call your own!

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Bernie eating popcorn

Some promotional products require a runner to complete the molding process. These runners support the product as it is being shaped. Once the product is cooled, the runner is then reused as pellets to restart the injection molding process for a new product.

What Products are Created Using Injection Molding?

Of course, not every custom item we offer is created using injection molding. But some of your favorite promotional products go through the hopper and come out as branding beauties! Take a look at some of the promos that are created by injection molding:


Plastic pens - Who doesn't need to write out a to-do list or sign an autograph from time to time?


Frisbees - From the beach to the college campus, the custom Frisbee is an essential product to have on hand.


Pill containers - Custom pill boxes have a place in everyone's medicine cabinet, storing everything from antibiotics to vitamins.


Bandage dispensers - For those who are especially accident-prone, you can't go wrong with personalized bandage holders.


Water bottles - Not only are custom water bottles eco-friendly, they're also an extremely popular promotional product!

Bernie breaks it down

Injection molding is a nifty process for shaping plastic or rubber. Whether you're looking for custom Frisbees to toss out to college students or personalized water bottles for your thirsty customers, you have injection molding to thank for your favorite promos!

Quality Logo Products are experts on all things printed and promotional. Let our team of awesome, incredibly good looking, and fun promo nerds help you select awesome promotional swag today!

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Alyssa Mertes

Alyssa Mertes

Alyssa is the Lead Copywriter at Quality Logo Products. As a promo expert, she's uncovered the world's first custom tote bag, interviewed the guy behind rock band ACDC's logo, and had a piece published by the Advertising Specialty Institute, a leader in the promotional products industry.