While 3D printing and plastic injection molding are immensely different manufacturing processes, they both hold valuable places in modern manufacturing. They have a lot in common too. They are both meant to make a designer’s vision a reality as effortlessly as possible. Both are primarily used in producing complex plastic parts and components, among many other things. Even though they can get you the same or similar result, they are considerably different manufacturing processes.
For one, 3D printing is an additive process. As it manufactures objects by building them up layer by layer, you can observe the building process as it happens, which is always beneficial when testing a brand new design. In plastic injection molding, first, an object’s inverse is formed out of a material that is safe to handle the molten plastic. Afterward, the molten plastic is poured into individually carved molds. Once the plastic cools down in the mold, the finished object is ready to use. It’s essential to realize that there are significant differences between the two manufacturing processes and our short overview will definitely help you to determine which one will work better for your application. Without further ado, here is an overview of the two manufacturing techniques altogether with their pros and cons.
Plastic Injection Molding
This manufacturing process is widely used when there is need a large number of plastic parts or components to be made at one time. It’s frequently used in mass production, where a single element has to be reproduced with strict fidelity for a huge number of finished items. The chances are that you use something that was built using plastic injection molding technology every single day. For example, the handle of a screwdriver is precisely like the handle of every other screwdriver from the same brand, with the same bumps and dips for grip. That’s because the company used an injection molding technique to ensure that all of those design quirks stay the same on however many screwdrivers they sold to stores.
- Plastic injection molding is one of the most efficient manufacturing processes for producing large quantities of the same thing. The plastic parts created with injection molding are always virtually identical, no matter how many you want to produce or how long you repeat it. Repeatability is one of the most significant advantages that this manufacturing technique offers to anyone who needs branding consistency.
- Another great advantage of plastic injection molding is that the finish of products is always looking smoother than those that have been 3D printed. Instead of building up the material in layers, injection molding creates one smooth outer layer all at once through its pouring method.
- Injection molding is excellent in mass production. Producing lots of clones of the same part or component is invaluable when manufacturing on a large scale. If you have the up-front costs of the operation covered, the price to produce each part or component will go down exponentially once you start creating them.
- Plastic injection molding can produce bigger parts than 3D printing. Even though it has its limits for each piece’s size, injection molding can work on a bigger scale because of the industrial range of its tools. This is a significant benefit for objects that will see heavy mechanical or manual use.
- Plastic injection molding produces more scrap than 3D printing. This is because of the mold, and whenever a shape is carved out of a larger piece of material – there are going to be some scrap leftovers.
- Purchasing injection molding tools will make a significant financial impact on your company at the start of the project. The right solution here is to work with an outsourced third-party company that embraces plastic injection molding manufacturing of parts.
- It’s difficult to impossible to change anything about your design once the production is finished.
As you already know, 3D printing creates an object by printing thin layers of the filament on top of one another to form a finished product. 3D printing rises from the same family of processes like injection molding and is a valuable step in the beginnings of its stand-alone way to build finished products.
Photo from Pixabay
- 3D printing is frequently used and offers precise speed and cost benefits for low-quantity applications such as prototypes development. Because of the very little machine setup time and no need for costly mold tool construction, 3D printing is widely used to create top quality one-off prototypes.
- As plastic injection molding is time-prohibitive because of the lack of a mold to be developed and manufactured, 3D printing can get parts to you in a matter of days. Besides, it can remain cost-effective in quantities up to several hundred pieces.
- 3D printing technology is excellent for the production of highly complex parts. 3D printing allows for more complex geometries and unique contours to be created. Even though for higher production runs injection molding will likely need to be incorporated at some point, 3D printing is the more facilitative process for testing the limits of a particular design.
- Three-dimensional printers are somehow limited to what they can print size-wise to the printer’s physical dimensions. You can still use a 3D printer to print parts that go together for a bigger whole, but that will add countless hours of work that you may or may not have.
- Compared to other manufacturing technologies, 3D printers are limited in their ability to create more than one object. They are additive, which means they build their objects layer by layer instead of all the layers being poured at once like in plastic injection molding. That being said, it takes hours to create a single finished object and is certainly not the top choice if you need to mass-produce a plastic part or component.
In case you’re looking to manufacture a lot of the same things in a short period, and you already have a bulletproof design, plastic injection molding is the way to go. If you need lower barriers to start your production and experiment with your product designs without running a whole batch – you will be okay with 3D printing technology. They both come with particular advantages and disadvantages for different steps of the producing process, so take your time, consult with reputable professionals, and find the most suitable way to bring your creations to life.
Author | Emily Forbes
An Entrepreneur, Mother & A passionate tech writer in the technology industry!