Printing for potatoes

Additive Manufacturing

Printing for potatoes

By Nick Wright

Above: Idaho Steel CEO Alan Bradshaw says the ProX 500 3-D printer quickly creates custom potato forming tools for the machines the company fabricates.

Food processing machine maker adds 3-D printer to reduce time and cost of parts, freeing up fabricators

February 2016 – Founded in 1918, Idaho Steel has evolved with an industry whose demand is resistant to just about any economic condition: food. Based in Idaho Falls, Idaho, the company manufactures food processing equipment that is closely associated with the staple for which its home state is known: potatoes.

The company started out as a small fabrication shop. Fast forward to WWII. Idaho Steel’s machines were among the first to produce dehydrated potato flakes and granules for the Army. According to the company, many of Idaho Steel’s potato processing machines from 50 years ago are still in operation. Idaho Steel says in 1978 it introduced the potato industry’s first rotary former, a stainless steel machine that mass-produces the well-known Tater Tot.

In recent years, it has worked closely with the likes of McDonald’s, Ore-Ida and other household names in food to form potatoes into fries, hashbrown patties and other shapes. In 2008, Idaho Steel tweaked its Nex-Gem machine (the name of its rotary former) to quickly remove potatoes from the tool patterns that stamp them into shape. Over the years, Idaho Steel’s customers began requesting more complex potato shapes, which required the company to quickly create tooling patterns and ship them out. That made it possible for customers to continue around-the-clock food production with no downtime.

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This piston, used in a potato forming process, would take 250 hours to CNC machine from metal. Printing it takes 90 hours.

All of those parts and shapes traditionally were manufactured from a different plastic with CNC lathes and mills, which meant always having an operator at a machine, said Alan Bradshaw, Idaho Steel’s CEO, in a webinar. Moving through that manufacturing process was arduous, and took as long as 250 hours to fabricate a complete set of patterns and pistons. Some of those patterns had as many as 80 components to a machine, counting the fasteners that join the parts together.

These labor intensive tasks sent Idaho Steel in search of a faster way to produce potato-stamping patterns. It turned to 3D Systems, Rock Hill, South Carolina, for a 3-D printer to cut down tooling time. Initially, Idaho Steel bought a desktop 3-D printer in 2013 to tinker with the possibilities the technology offered.

Working through Intermountain 3D, a local dealer for 3D Systems machines, Idaho Steel bought a ProX 500 SLS (selective laser sintering) machine. Mind you, this isn’t a metal printing machine, rather one that prints DuraForm, which is 3D Systems’ hard thermoplastic. It has since cut down pattern production time by nearly a third. And, because operators aren’t needed to tend to the machine, they are freed up for other fabrication tasks.

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The pistons are the potato-forming component of Idaho Steel’s rotary former.

Faster fries

According to Idaho Steel, it would take 25 days to fabricate the parts for a complete set of potato patterns, figuring 200 to 250 hours divided by 10-hour shifts. Now, that time has been slashed to about 90 hours, or five days, without limitations of man-hours because the ProX 500 can run lights out regardless of weekends. These parts don’t need post-processing or assembly as they would have had they come out off the CNC mill. If a customer wants to test a sample shape, the ProX 500 produces it on-the-spot once Idaho Steel’s engineers draft a design.

The rotary formers hold 16 sets of pattern assemblies. By printing the parts, a complete set can be produced in just six hours. The pattern-piston assemblies are usually 18 inches long, Sales and Marketing Manager Jon Christensen said during a webinar in December 2015. “The ProX 500 was a perfect fit.”

With such a drastic turnaround in delivery times, the problem of scheduling fabrication and machining has been nearly eliminated, according to Bradshaw. “It’s been a substantial advantage for us. Making these parts from a single piece is huge for us and our customers,” he said during the webinar. Because there isn’t assembly required, the printed parts are stronger, as well. “It’s opened up our traditional CNC machines to take on other work that we wouldn’t have been able to do otherwise. We haven’t scaled back in man-hours or machining. We’ve just increased our throughput. Results for us have been good.”

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Parts are printed into a mold, after which they require no finishing.

For another part, Idaho Steel cut the cost of a CNC part down from about $500 to $50 with the ProX 500, because it was able to print threads instead of having them machined out. The company has also experimented with printing parts it otherwise can’t get off the shelf, as well as printing scale models of its food processing equipment to show customers.

Tough materials

The DuraForm thermoplastics are tough, and thus ideal for Idaho Steel’s applications, said Tom Charron, vice president of product marketing at 3D Systems. The material is known to be used in Lockheed Martin’s F-35. “They’re durable for production use, and the ProX 500 is a high production system so it’s good for larger volumes,” he said. There are no post-processing requirements, as SLS-produced parts need only be broken from the powder cake they’re embedded in. Users blow off the powder and hit them with a bead blast, then they’re good to go. No curing or washing needed.

Not only is a one-piece solution ideal for minimizing assembly, the SLS process plays into sanitary considerations—one of Idaho Steel’s top priorities. Anywhere the company can eliminate the potential for contamination risks, like from fasteners, is an added benefit. There is no porosity with the DuraForm, reducing the risk of bacteria, according to 3D Systems. Plus, according to Christensen, there is always the human factor: Fasteners can be overtightened (or not tight enough) and damage the parts.

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Idaho Steel has fabricated food processing machines since 1918.

Idaho Steel also revamped a housing piece for a laser that detects the material level of a hopper or bin and sends it to the control system. Before, Idaho Steel contracted another company to make this part, but it had quality issues. Using the ProX 500, Idaho Steel made some improvements and modifications. The opening at the top was expanded for easy access to the sensor, corners were smoothed and a plastic chain connecting the screw-top cap to the housing was printed into the part. This tethers the cap to the sensor, preventing it from getting lost.

Idaho Steel is just one fabricator that’s harnessing the advantages of 3-D printing, whether it’s plastic or metal. It’s a process that is gradually becoming another tool in a shop’s toolbox, rather than replacing existing processes. A look around Idaho Steel’s shop reveals that, despite its investment in 3-D printing, it’s very much a fabrication operation with over 100 employees. It has a Cincinnati press brake, Mazak CNC machines, and the trappings of a metalworking shop. But 3-D printing is finding its way into fabricating operations and making them more efficient.

As milestones go, 100 years in business isn’t an easy one to reach. With two years to go, Idaho Steel is poised to exceed it, so long as there are enough potatoes to go around. FFJ

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