Injection Molding Vs. 3D Printing: The Differences
When it comes to comparing injection molding vs. 3D printing and making a manufacturing choice, several factors come into play. Both techniques offer distinct advantages and disadvantages. However, one must offer more benefits than the other to suit a specific project or application.
To help you make that important choice, we’ve compared the two methods side-by-side. First, we’ll see what each means then look at a point by point comparison before answering a few more questions about the two processes.
Injection Molding Definition
The injection molding process is used to mean a manufacturing technique where molten material, usually plastic, is forced into a molded cavity, often made of metal. The molten material cools and hardens until it takes the shape of the required desired or product.
The injection molding is one of the most popular types of part making technologies today, with manufacturers using it to inject mold everything from plastic toys to automotive parts.
According to a report released by Business Wire the injection molding market will grow with CAGR of 4.8% between 2022 and 2030.
3D Printing Definition
3D printing is a digital parts-making process that, using plastic or plastic-infused material, produces three-dimensional objects using a computer file. The object is brought to life by creating it layer by layer, which makes it an additive process.
Materials used for this method include plastic, metal, and rubber. Because it requires minimal tooling and setup, 3D printing is often used to quickly produce parts – and sometimes competes with injection molding in terms of benefits, as you’ll find out below.
Injection Molding Vs. 3D Printing
Now that you know the definitions of injection molding and 3D printing, let’s take a look at their pros and cons in more detail. This will include everything from the cost of each process to the materials used, parts strength or, in general, the advantages and disadvantages of 3d printing compared to injection molding.
1. 3D Print Vs. Injection Mold
In 3D printing, there’s usually no need for a mold, as the object is built layer by layer, usually on an open base. This makes 3D printing a great choice for one-off, prototyping and low-volume production of parts since lead times are much shorter.
The cost of 3D printing vs. injection molding is also relatively low, as the only major startup costs are material and printer acquisition costs. It also allows for more intricate shapes that may not be possible with injection molding.
Injection molding, on the other hand, requires a custom mold, which can be expensive and time consuming to produce. But once it is created, the cost per part is generally low, and large quantities of parts can be produced quickly and efficiently.
2. Injection Molding Vs. 3D Printing Cost
The cost of injection molding manufacturing process vs. 3D printing varies depending on the type of part and its complexity. Generally, parts produced by 3D printing are more expensive than those produced by injection molding, but this isn’t always the case.
3D printing is a better option for lower volume runs or one-off parts since the cost per part is lower than with injection molding. For larger runs, where the cost of the custom mold can be spread across a higher number of parts, injection molding is often more economical.
3. Injection Molding Vs. 3D Printing Strength
The strength of injection molding parts vs. 3D printing parts depends on the type of material used and the complexity of the part. That said, molded parts are normally stronger – and for several reasons.
Consider this: With injection molding, parts are produced in single shots per unit, in a controlled environment with a distinct pressure and temperature. This can yield parts that are stronger than 3D printed products.
With 3D printing, the parts are built from the ground up in a layer-by-layer process. This can result in weaker parts at the layer joints. So 3D printing is often used for prototyping or low volume runs of complex parts that would be difficult to produce with traditional methods.
4. Metal Injection Molding Vs. 3D Printing
Both injection molding and 3D printing work best with plastic parts, but metal injection molding (MIM) is becoming an increasingly popular option for producing metal parts.
Metal injection molded parts are produced using a mix of powdered metals and wax or other material binders. Injection molded metal parts, when compared to 3D printed metal parts, are stronger.
3D Printing Or Injection Molding?
The choice between 3D printing vs. injection molding comes down to the type of parts you need to produce and the quantities required.
- If you’re looking for a quick, one-off prototype or a low-volume production run of complex parts, then 3D printing may be more advisable: It offers shorter lead times and lower cost per part.
- However, if you’re looking to produce higher volumes of parts or need parts that are stronger with greater precision, then injection molding is the way to go.
- Because, except for the initial investment in the custom mold, injection molding cost per hour is generally low.
No matter which manufacturing technique you choose, it’s advisable to consider your options and determine what will work best for your application. Once you have a clear idea of what you need, the decision between injection molding vs. 3D printing should be much easier to make.
Will 3D Printing Replace Injection Molding?
While it’s true that 3D printing has become a very popular method in recent years, it’s unlikely that it will replace the injection molding technology entirely. The following points explain why this is the case:
- Injection molding remains the preferred option for higher-volume production runs and for producing parts with greater strength and other features.
- Both 3D printing and injection molding are often used in conjunction with each other, depending on the application.
- With ability to melt waste plastic and mold it to become useful products, injection molding is the ideal method for processing recycled plastic materials.
Therefore, whereas 3D printing can be great option for certain applications, it can only exist alongside injection molding. That being said, as both technologies continue to develop and refine, more and more possibilities may open up. But for now, the advantages of each process remain distinct enough to make a clear distinction between them.
The question whether to use 3D printing or injection molding depends on several factors. As we have seen, both methods are viable options and your project needs will dictate the best choice to make. Injection molding is best for high-volume production runs and offers great precision and strength, while 3D printing is ideal for quick prototyping or low-volume production with complex parts.