3D printing material resists harsh solvents

Most 3D printing materials do not need to handle harsh chemical environments. For two engineers at Whitford Worldwide, however, this was not the case. The manufacturing process often puts machine components into harsh chemical solvents. This need almost derailed the use of 3D printing.

Whitford Worldwide manufactures specialty coatings, with products ranging from non-stick coatings for pots and pans to non-corrosive layers for industrial parts. Under the same roof is Polymeric Systems, owned by Whitford, and manufacturer of epoxy sealants and adhesives. Jon Fetzer and Bobby Colmery work as process engineers at the companies. Because many of the machine components the company needs must be resistant to solvents, they usually send the components out for custom machining, a costly and time-consuming process.

One example was developing a better way to wrap extruded epoxy in plastic film. “It has always been a big problem,” notes Fetzer and Colmery, “and takes a little bit of black magic to get it to wrap to a satisfactory level. They went down several avenues to solve the problem, and ended up with an idea for a 3D printed wrapper.

However, due to a design change, they had to scrap that idea and start over. “We tried several iterations and couldn’t figure out how to get it to work reliably,” Fetzer explained. “We went to a new design, switched gears, and thought 3D printing was out.”

The team then arrived at a concept for a film rolling apparatus to guide the film around the epoxy extrusion. They sent the design to be machined by a third party machining resource and got back a quote of around $2000.

“After receiving a quote for $2000 from a machine shop to fabricate the apparatus, we determined that price was too steep for another imperfect design that will no doubt need more changing. We really loved the concept of 3D printing and thought ‘man, wouldn’t it be awesome if we had one of our own? We could do all this testing and tweaking in-house.’”

The two engineers laid out four essential criteria to justify the purchase of a 3D printer. The printer needed to be cost effective and user friendly, it needed to print functional parts, and its material needed to be solvent resistant.

“We looked into all types of printers; from $800 desktop printers to $140,000 industrial strength printers,” says Fetzer.

After selecting a few potential printers with the necessary capabilities, they started looking at materials. They received material samples from a few different vendors, including Markforged, and placed them in some of their harshest chemical solvents.

“We went through the process of elimination of materials,” Fetzer explains, “Some of them completely dissolved…we tested the MarkForged nylon and that eliminated all the other printers, really. It was the only one that held up to all the criteria that we had…the nylon went through a 26-hour bath in a really harsh solvent and it still looked beautiful.”

Markforged nylon proving its chemical resistance holding up to solvent baths.

The chemically resistant 3D printing solution they found was in the engineering strength nylon of the Mark One.

Once Fetzer and Colmery had narrowed their options down to the Mark One, the next challenge was convincing management that the purchase would be worth it. Many of the machines at the company are decades old and get the job done. A 3D printer would be the most modern piece of equipment, but nobody was familiar with its benefits.

“The whole 3D printing concept was foreign to us until we started looking into it,” Fetzer says. “We had to sell the concept first, before buying it.”

Everyone in management agreed that the roller assembly was vital to the epoxy manufacturing process, and that they needed to make it somehow. With the Mark One priced at about $5,500, and a single machined roller at $2,000, it was a fairly easy sell.

“When they saw the cost of that and the cost of the Mark One, we found other items we could invest in, and that pretty much sold it right there…,” Colmery says. “It was the cost itself, and that we no longer needed to rely on suppliers for some of our other parts.”

With the Markforged printer, both Whitford and Polymeric Systems could manufacture and prototype many chemically resistant parts at a fraction of the price it would take to get them made elsewhere. The cost of machined prototypes created for the film roller would have definitely exceeded the cost of the Mark One: “The Markforged has pretty much paid for itself…the number of iterations we made with that film wrapper, I don’t even know how much that would have cost. We definitely saved a lot of money.”

A 3D printed nylon roller for one of Whitford Wordwide’s manufacturing processes.

Upon receiving their Mark One, the pair immediately set it up: “we were printing something within the hour…it all went together perfectly and it just worked.” The two now incorporate 3D printed parts into other fixes: “a lot of things we see around here, we say ‘hey…maybe we can print that.’ It’s a great experience.”

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