If popular culture is any bellwether, a clear winner already exists in the battle between 3D printing versus injection molding. However, in the real world, 3D printing, or additive manufacturing, and injection molding rarely compete for industry attention. If anything, the two manufacturing processes are so complementary, you almost can’t have one without the other.
It’s understandable, since 3D printing sounds – and often looks – like something out of science fiction. It regularly appears in movies and on television, usually as the solution to an outrageous plot, leaving viewers with the impression that 3D printing technology is a bit of a miracle.
There are amazing examples of how professionals across industries are using 3D technology. The “miracle” may be how engineers can turn a CAD model into a working prototype within hours, and, in many cases, a final product within days. This is a boon to the health care industry.
Quick turnaround times are crucial in healthcare, where medical manufacturers use 3D technology to create all manner of medical tools and anatomy-based, patient-matched products, such as complex knee replacements with porous materials that promote tissue growth and integration.
Additive manufacturing solutions are growing in popularity, too. U.S. hospitals with centralized 3D printing facilities have grown from three in 2010 to more than 100 in 2020, providing point-of-care product development for hundreds of patients. During the coronavirus pandemic, 3D printing techniques were used to design and produce better-fitting masks and even create 3D printed swabs for COVID-19 diagnostic use.
Injection molding machines are the workhorses of the high-volume plastics industry, a $360 billion trade in 2020. Plastic injection molding, like its flashier cousin, also plays a critical role in the U.S. medical industry.
Like 3D printing, the health care industry relies on medical-grade plastics injection molding manufacturers to produce everything from laboratory instruments and surgical equipment to implantable components. Clinicians rely on the manufacturer’s ability to provide tight-tolerance production, in which every micron makes the difference between patient success and component failure.
Medical manufacturers benefit from an abundance of available plastics materials, even when factoring in the need for stringent federal compliance and contaminant resistance. These materials offer exceptional durability and heat resistance, making some medical tools nearly unbreakable and immune to repeat sterilization.
While both injection molding and 3D printing are critical to health care, each technology is employed in a multitude of other industries. And every project has a reason to use one process over the other - or use both in tandem.
Additive manufacturing, for example, has evolved from the rapid prototyping of component models into a solution specializing in low-volume production runs. Rapid prototyping still plays an important role in the design process, allowing designers to print, test and modify parts as often as necessary – faster and more cost effective than injection molding. This flexibility allows for low volume runs, but the 3D printing cost vs injection molding makes high volume production runs untenable.
Other benefits include:
Today, 3D printing is a $16 billion industry yet remains less than 1% of the global manufacturing market. In many ways, additive manufacturing is still in its infancy when compared to plastics injection molding.
Injection molding traces its roots to the late 19th century and has evolved into one of several integral manufacturing methods supporting everything from electronics to the automotive industry. Plastics injection molding is both affordable and high-quality, and has, in many ways, become the go-to for advanced technological and scientific applications.
Manufacturers typically run into budget trouble, however, if the process requires several part iterations. Steel-made molds cost money and take time to produce. For this reason, injection molding is considered less flexible than its younger cousin. It is the right choice, however:
Most manufactures find that the decision to use 3D printing or injection molding is rarely a one or the other choice. Ideally, they are used in conjunction with one another, complementing the process. Some manufacturers, for example, enlist 3D printing to create tools to assist with injection molding, finding that this helps reduce development time and lower tooling costs.
Essentium, an additive manufacturer based in Pflugerville, Texas, combined 3D printing and injection molding to rapidly develop face mask frames for frontline workers during the coronavirus pandemic. Using 3D printers, the company tested parts against various weather elements, checked for color fastness, and subjected prototypes to different post-process surface finishing to establish predictable and repeatable results for the final injection molded part.
Any manufacturing process, including injection molding, is only as efficient as the machines that do the work.
While 3D printing and injection molding work well side-by-side, the loss of a machine part to failure can increase time and cost. They keep things running smoothly, Parker provides solutions, assistance and an array of plastics injection molding components.
The same applies to both an injection molding machine and a hydraulic press: a solid industrial hydraulic motion controller teamed up with DCP Technology and Parker’s high-performance servo-proportional valves will support a more efficient, quieter operating, high-performance machine.
Article contributed by our Fluid and Gas Handling Team and Rashid S. Aidun (top) who draws on his electrical and fluid power background to create custom drive controlled pump solutions. Prior to joining Parker 16 years ago, he worked as industrial manufacturing and fluid power and controls engineer for various OEMs. He has a BSME from Syracuse University.