Is injection molding stronger than 3D printing?



1. Introduction

2. What is injection molding?

3. Strengths of Injection Molding

4. Limitations of Injection Molding

5. What is 3D Printing?

6. Strengths of 3D printing

7. Limitations of 3D Printing

8. Conclusion


As industries have expanded their applications in manufacturing in recent years, various materials have been created to meet production demands. Among these, injection molding and 3D printing technologies have gained a significant advantage in manufacturing because of their ability to produce parts quickly, efficiently, and accurately.

Injection molding and 3D printing are two manufacturing methods that are often compared regarding their strength in producing parts. While both have their advantages, many businesses must decide which option will work better for their product specifications. So, is injection molding stronger than 3D printing? Let’s explore the differences and similarities between these two manufacturing methods.

What is Injection Molding?

Injection molding is a standard manufacturing process used for mass production in various industries. It involves a small amount of melting thermoplastic, thermosetting polymers, and metals or ceramic powders located in a heating chamber, then being forced at high-speed into a mold cavity whose shape determines the desired output. Once inside, the material cools and solidifies, and the part can be removed from the mold.

Injection molding can produce large quantities of the same high-quality and accurate parts with efficiency, speed, and less need for human intervention. For example, it can produce parts such as electronic housings, handles, knobs, automotive parts, and medical devices.

Strengths of Injection Molding

1. Low-cost of production per unit

Injection molding requires high initial costs for tooling but can produce subsequent units at a lower cost per unit. The cost-effectiveness of injection molding ensures that businesses producing large orders of parts will produce high-quality parts at a much lower price than other manufacturing methods.

2. Faster production and consistency

Since injection molding works based on pre-programmed software that determines the exact size and shape of a product, once the manufacturing process starts, it can continuously produce the same products at a fast rate while maintaining consistent quality.

3. High-quality and accuracy

Injection molding offers the capability of producing parts with high-quality and accuracy. Due to its high-end molding process, each part has high accuracy, repeatability, and minimal defects.

Limitations of Injection Molding

1. High-cost Mold production

Injection molding requires high initial tooling costs. The higher the complexity and size of the part, the more expensive the tooling cost can become.

2. Lead time of put into production

The lead time from design to product fulfillment can take weeks, if not months to fulfill the order. It may require a significant amount of time to design and construct the precise mold needed for the production of the desired part.

What is 3D Printing?

3D printing, also known as additive manufacturing, is a process that builds parts layer by layer in a 3D printer based on design specifications. It starts with a 3D CAD (Computer-Aided Design) model creation, which the 3D printer can read and build. The printer uses a thermoplastic, thermosetting plastic, metal powders, ceramics, or other materials to produce the parts. 3D printing has revolutionized manufacturing and prototyping, as it allows engineers to create custom parts with complex geometries quickly and at a lower cost than in traditional machining.

Strengths of 3D printing

1. Fast production and Short Lead-time for Prototyping

Since 3D printing removes the need for tooling, production phase begins immediately after the CAD Data upload. It also enables rapid prototyping and reduces the lead time from design to the finished product. 3D printing can also provide useful insight into the final part's quality by creating a quick physical version of a design that can help identify and correct design improvements.

2. Customization

3D printing offers unique customization possibilities since it allows the creation of complex geometries that traditional manufacturing methods cannot accomplish. It can also produce parts in different materials and colors while maintaining high accuracy.

3. Cost-effectiveness

3D printing offers cost savings for small and medium-volume manufacturing because of its minimal setup, tooling, logistics, and production turnaround.

Limitations of 3D Printing

1. Limited materials

Although 3D printing uses an extensive range of materials, it is still limited to closely related materials like plastics, composites, and metal powders. The material quality can also degrade over time due to thermal factors.

2. Lower Strength and ability to sustain high temperatures

3D printing incorporates additive layering of materials, which can lead to weaknesses in the grain structure, causing it to be less strong than injection-molded parts. Additionally, most of the material is often limited in its ability to handle higher temperatures compared to injection molding processes materials.

3. Lack of accuracy and repeatability

3D printing's accuracy level largely depends on the printer's quality and is prone to human error. The quality of printed parts may vary, leading to inconsistencies between multiple prints.


Both injection molding and 3D printing can produce parts of varying qualities, accuracy, and consistency. However, injection molding remains stronger than 3D printing, mainly because it can produce higher strength parts compared to 3D printing counterpart.

Injection molding offers higher-quality and more accurate parts with more excellent consistency, making it ideal for industries where reliance on durable and high-quality parts are mandatory. However, 3D printing provides a manufacturing method that promotes customization of parts and unique design features.

The decision to use injection molding or 3D printing entirely depends on the product specifications and manufacturing needs. Companies should consider the strengths, limitations and product requirements when choosing their preferred manufacturing method.