Plastics Assembly Expert Joins Development and Production via 3D Printing

As the automakers centered in Detroit have been chasing electrification and faster, more agile product development, a manufacturer on the other side of the state of Michigan has felt a shift in the supply chain for polymer parts. In the past, vehicle development was slower, more in line with the lead times expected for injection mold tooling. If new plastic parts couldn’t be sourced in time, automakers often had the option to pull from inventory developed for previous years’ models to get cars into testing and fulfill early purchases. But electric vehicles often don’t have this luxury; whether developed by startups or legacy OEMs, EVs tend to be new vehicle platforms without legacy parts to fall back on — and they are being launched into the market at accelerated rates, creating a demand for faster production.  

Indeed, the overall vehicle design cycle has dropped from four years down to two, says Andrew Roderick, senior applications and sales engineer at Extol, the aforementioned manufacturer located in Zeeland on the west side of Michigan. If an injection mold takes 3 to 6 months to obtain, that means a wait that was once maybe an eighth of the total development time might now take up to one-quarter of the entire cycle. And if legacy inventory isn’t a viable option for these new vehicles, automakers are left scrambling for parts and their suppliers are challenged to deliver them.

But for Extol, this shift and the timeline compression it brings present an opportunity. The company has been in business for more than 35 years providing automated systems that perform various joining operations on plastic parts, often parts that will go on to be used in cars. But now Extol is no longer only assembling discrete parts made elsewhere; it is producing its own, through Multi Jet Fusion (MJF). The polymer 3D printing process has turned Extol into a parts producer, and one uniquely positioned to serve the accelerated timelines of the development of vehicles and other products.

3D Printing Supports Different Lifecycle Steps

Extol’s primary business segments are plastics assembly technology and custom automation systems to apply it. The company has deep understanding of the options available to unite different plastic components, from laser, ultrasonic and hot plate welding to its proprietary NanoStake process. These joining techniques are provided to customers within fully tooled and automated machines; the company will also provide joining services for low volumes of parts — a few hundred or a couple of thousands — while the machines are in production.

Customers for plastics joining technology and services range from Tier One and Two automotive suppliers to medical device manufacturers to consumer goods providers. Although Extol’s additive manufacturing capabilities are much newer than these other technologies, the customer base making use of the company’s three MJF printers from HP does have significant overlap with its typical clients. Companies feeling the pressure to bring products to market faster, to iterate designs while at the same time pursuing sales, and to put off mold purchases for as long as possible are finding a solution in polymer 3D printing — and they can access that solution through a supplier they might already know.

“It’s the same customer base to some extent,” Roderick says. “But we’re now supporting different parts of the lifecycle.”

Rather than stepping in at the end of development to help automate joining processes that support production, Extol is now jumping in at the beginning of a product’s lifecycle, and taking part in the early stages of product development. This has entailed developing frameworks and methodologies to get at customers’ true goals. It has meant being open and flexible with design changes, collaborating with clients to get it right. And it has meant taking on part production to support both initial and ongoing sourcing needs.

Previously, Extol might have been receiving hundreds of prototype injection molded parts to assemble with prototype tooling at its Process Development Center in Zeeland. Now, it is leveraging 3D printing to produce short runs of maybe 20 or 30 parts at a time before proceeding with assembly. The production capability means that customers can develop new products faster and get functional parts into testing sooner, before investing in mold tooling. This 3D printing work perhaps sits somewhere between “functional prototyping” and “bridge production,” but either way, the deliverables are functional, end-use parts just provided in lower quantities lower than full scale.

Meanwhile, bridge production also offers opportunities to enhance the design. The automotive interior cartridges pictured above  represent a large 3D printing production job for Extol; there are four SKUs in the job (right and left versions of two components) and the full production run amounted to 52,000 parts, or 95 MJF builds. But unlike a typical serial production job where parts are made identically every time, additive as the production technology allowed the automotive customer to continue to iterate (in this case, three different times) even as it started to put cars into testing and into the market. 

Sometimes the changes are even faster. A production run of bezels for automotive sensors, for instance, saw the same number of design iterations within a much smaller quantity. 

“Within 500 parts that we printed, they made three changes,” says Kyle Harvey, business unit manager for additive manufacturing. This is not just additive manufacturing taking over production; it is a different kind of production all together.

Joining New Markets

Automotive applications make up about 60% of the work currently being performed on the Multi Jet Fusion 3D printers. But this 3D printing capacity is also allowing Extol to find new business opportunities in additional industries, beyond those it has traditionally served.

“We’re adding value for the customers we already have, and diversifying business at the same time,” Harvey says.

The orthotics and prosthetics market is among those diversification opportunities. Newer customers include Fited, which provides scoliosis braces, and Spentys, a supplier of braces, splints and similar devices. These parts are production products as well, but they are needed in batch sizes of just one — each item is unique to the patient.

They are also larger parts, which can pose difficulties in build planning. Fewer parts per build means less efficiency and reduced printer utilization, which hinders Extol’s ability to scale. “Making one large part is easy, because you can pack other small parts in around it,” Harvey says. “But making 100 is challenging; it fills the build and takes up too much space.”

Fitting a single part as large as a scoliosis brace into the MJF build volume is possible, but not efficient. The solution to this challenge is something the company already knows well: joining. Rather than print each brace whole, Extol divides the print into 10 to 15 discrete parts. These smaller pieces can be more easily nested into the envelope with other jobs for better printer utilization; their smaller size may also lower the build height and therefore reduce print time. Once depowdered, the parts are ultrasonically welded together to achieve the same result.

“We’re not scared of assembly,” Harvey says, and this allows the company to realize the benefits of printing parts in pieces. “Splitting large parts saves cost, improves throughput and makes printing faster.”

Functional Parts, Fast

Currently more than 90% of the 3D printing performed at Extol is for outside clients, but the company has benefited from this technology internally as well. It has also become a valuable tool in developing and manufacturing the company’s own automated systems including its NanoStake and Infrastake products. The NanoStake product alone has 10 different 3D printed components, made with technology from HP, Formlabs and Origin. Handles, button covers, HMI casings, custom fixtures, robot end of arm tooling (EOAT) and more have been produced through 3D printing for the automated joining equipment the company provides.

Perhaps the most striking example of how 3D printing has accelerated and improved Extol’s own equipment development is a component not even visible in the final product: a tiny electronics holder used in the company’s NanoStake products. These systems perform precise heat staking, a process that quickly heats and cools a punch to form a plastic boss into a stake that holds parts together. The electronics holder was originally designed for injection molding, but the company decided to pursue production through 3D printing instead. This choice opened the door to new design possibilities as well as rapid iteration through the company’s in-house Formlabs printers. The initial AM design to launch took only two weeks, and design improvements for manufacturability continued even after launch.  

The part is now produced using Origin technology by an outside provider, but its journey illustrates what might be the great promise of additive manufacturing for new products. AM may never deliver quantities competitive with injection molding, but its benefits are more relevant early on, in the development phase of the lifecycle. The ability to obtain functional parts right away through 3D printing gives OEMs the power to accelerate their timelines, to iterate designs, and to arrive at the best possible product as quickly as possible, whether it be a piece of industrial equipment or the next generation of electrified vehicles.