3D vs. Injection Molding: Which Should You Use?

Comparing 3D printing vs. injection molding parts
Comparing 3D printing vs. injection molding parts
Resource: https://www.youtube.com/watch?v=xn_eVKm_2hM

The question of whether 3D printing or injection molding often comes up when creating parts and prototypes. To help you decide which process is right for you, we’ve put together a quick overview of 3D printing vs. injection molding. This should give you a better idea of the benefits and drawbacks of each method.

3D Printing

3D printing refers to a technology that can be used to create three-dimensional by successfully adding layer upon layer of a thermoplastic or thermosetting polymers. It’s also commonly called additive manufacturing for employing an additive process to create the object.

Injection Molding

Injection molding is one of the most popular manufacturing processes for creating plastic parts. It involves injecting molten plastic into a mold, which is then cooled and ejected to create the final product. Injection molding is capable of producing parts of different sizes and geometries.

Using a 3D printer to create parts
Using a 3D printer to create parts
Resource: https://www.ey.com

3D Printing vs. Injection Molding: Pros and Cons

What is the difference between 3D printing and injection molding? To provide you will a good overview of the two technologies, we will compare them for different considerations such as cost, part strength, and more.

3D Printing vs. injection Molding: Strength

Although a lot depends on the type for 3D printing materials, in general, printed parts are not as strong as injection molded ones. This is because the layers of a 3D-printed object are not bonded as strongly as a single piece of plastic that has been molded.

If you need a part that is strong enough to withstand stress or wear and tear, injection molding is usually the better option. However, if you are just looking for a prototype or a part that does not need to be very strong, 3D printing can suffice.

That means there are situation when 3D printing parts will be better than making them using injection molding, mainly owing to some other attributes discussed below.

3D Printing vs. Injection Molding: Speed

Injection molding requires extensive setup/tooling time before actual production can begin. This is because the mold needs to be created first, and then the machine needs to be set up for injection molding.

3D printing, on the other hand, is much faster. You can print a part as soon as you have the digital file of the model is ready. This makes 3D printing the better option if you need parts quickly.

Situations that may benefit from the faster part production of 3D printing vs. plastic injection molding include, but are not limited to the following:

  • When you need a part for testing or prototyping and time is of the essence
  • When you need a spare part or replacement for an existing product

3D Printing vs. Injection Molding: Cost

The cost of 3D printing vs. injection molding can vary depending on several factors. In general, however, 3D printing is more affordable for small production runs. This is because you do not need to create a mold, which can be expensive.

Injection molding is usually more cost-effective for large production runs, as the price per unit decreases with larger quantities. If you plan on mass-producing a product, injection molding is usually the better option.

3D Printing vs. Injection Molding: Flexibility

The 3D printing process offers more design freedom than injection molding. This is because you are not limited by the size and shape of the mold, and can produce different parts without having to go through a tooling process.

With 3D printing, therefore, you can quickly create parts with complex geometries that injection molding would take a long time to create.

That makes 3D printing ideal for rapid prototyping, especially where unique shapes and detail are required. However, if you need a standard part that can be mass-produced, injection molding is usually more cost-effective.

3D Printing vs. Injection Molding: Part Size

When it comes to the size of the parts you can produce, injection molding has the upper hand. This is because the molds used in injection molding are usually much larger than 3D printers an therefore, the size of the 3D printed prototypes and parts.

However, with advances in technology, some 3D printers are now able to print parts that are larger than before, especially when using an industrial 3D printer. Users can also print a part in multiple sections and then assemble it later.

Overall, though, if you need to produce large parts, injection becomes the better technology, plus the parts will have superior strength if injection molded.

3D printing machine
3D printing machine
Resource: https://www.youtube.com/watch?v=f4RGU2jXQiE

Injection Molding or 3D Printing: Which is better?

The answer to this question depends on your specific needs. In general, when it comes to comparing 3D printing vs. molding, printing is more affordable and faster for small production runs, while injection molding is more cost-effective for large production runs.

3D printing also offers more design freedom but mostly for smaller objects, while injection molding is better for producing large parts. Ultimately, the best option for you will depend on the factors mentioned above.

Will 3D Printing Replace Injection Molding?

It is unlikely that 3D printing technology will replace injection molding, as the two technologies serve different markets. However, 3D printing is becoming more popular for small-scale production, especially for prototyping and spare parts.

Injection molding will continue to be the preferred technology for mass production due to its lower cost per unit. With that said, it’s probable that both technologies will continue to be used side-by-side in the future, just like they are today.


3D printing and injection molding are useful technologies that are being applied in a variety of industries. Each method of producing parts has its own pros and cons, as well as best applications. Before settling on either 3D printing or injection molding, be sure to consider the factors mentioned in this article. Doing so will help you choose the best technology for your specific needs.

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