When it comes to discussing additive manufacturing versus injection molding, oftentimes there is a stigma that makes them sound exclusive. That couldn’t be any further from the truth. In fact, 3D printing may be changing the injection molding process for the better by allowing for must custom designs and quicker problem-solving. Let’s explore this combination of traditional and nontraditional manufacturing techniques.
There are certainly advantages and disadvantages to additive manufacturing and injection molding alike. For most, the finish quality and reproducibility time of injection molding wins out on a production scale. While some may forecast that 3D printing will improve and overtake the injection industry, the more likely result is a meshing of the two technologies.
Here’s the problem with injection molding: the molds are expensive and often take weeks to develop. 3D printing, on the other hand, can develop a custom product in minutes or hours. The other burdening factor is cost. Molds for injection molding can be costly, in the tens to hundreds of thousands of dollars. Due to the costliness of IM molds and their development time, making changes is essentially impossible.
Injection molding manufacturers are now beginning to hybridize the IM mold making process by combining 3D printing with the process of IM. 3D printing is used to create injection molding prototypes. In other words, manufacturers can quickly print sides A and B of a mold and clamp it in place using traditional equipment. The molten plastic gets injected into the 3D printed mold, but the conditions have to be heavily altered when working with this new printed mold material.
This biggest difference in molding criteria you might expect comes when dealing with the plastic temperature. ABS printed molds will break down if continuously exposed to the high heat of IM, so the time between cycles has to be lengthened by up to a minute. This extended time allows for the ABS mold to cool and minimizes defects.
These unique problem-solving techniques are allowing injection molding manufacturers to utilize 3D printing in the design and prototyping process. It is hard to imagine 3D printing overtaking IM as a plastics manufacturing technique due to accuracy, speed, and repeatability. However, meshing the two technologies together arguably creates a better manufacturing and design process.
So, the future injection molding involves a lot of additive manufacturing – and both industries are better off because of it.