System Upgrades Push Precision to New Limits

By Troy Newport

If you close your eyes and think of a hospital environment you may recall the scent of cleaning agents, scenes of doctors and nurses dressed in personal protective equipment rushing to their next urgent duty, or specialized medical equipment that must remain spotless to protect the patients being treated. As it turns out, manufacturers that supply furniture and specialty equipment for the medical industry must be similarly concerned with precision and cleanliness.

Milwaukee-based Midwest Products & Engineering Inc. (MPE) was founded in 1978 as a precision metal fabricator for the medical and electronics industries. In 1983 the fledgling company opened a 2,000 square foot facility in Brown Deer, WI. By 1986, they were moving into a 40,000 square foot facility and adding another 10,000 square feet of paint and powder coating capabilities. MPE Sales Engineer Jeff Wasley says, “We started as a sheet metal manufacturer of medical carts and devices, so we always needed to have a finishing system. We started out with a wet paint system, but as [powder] technology grew and our medical customers added more stringent specifications to their products, we felt that powder coating was the way to go.”

Today their impressive operation has ballooned to a 220,000 square foot footprint with just about any design, prototyping, fabrication, and finishing capabilities you can think of. What hasn’t changed? They still specialize in designing, manufacturing, and coating products for the medical and electronics industries, and have an unrelenting focus on quality.

A dominant factor for maintaining quality, Jeff affirms, is cleanliness. One may think of cleanliness in terms of keeping the shop floor swept, changing booth filters when indicated, or even more proactive approaches to shop hygiene. For example, because they also have fabrication areas in their facility, MPE has invested in downdraft tables to use while grinding or performing other reductive processes to keep contaminants out of the environment. These kinds of precautions are certainly crucial to a quality finish and factors they take seriously, but for MPE it’s more than simply keeping their production space clean.

They also consider the condition of their substrates when delivered. Generally, they work with cold-rolled steel and aluminum. There are some instances where stainless steel and galvanized materials are indicated, but according to Jeff, more customers are turning to cold-rolled steel and aluminum. Luckily, he says, MPE is blessed to have a quality supplier. “It’s almost perfect when we get it in,” Jeff asserts. “They know our expectations,” he continues, “and so the surfaces aren’t scratched when it gets to us. There are a lot of cosmetic requirements from our customers, so it’s important we get [our metals] in the best condition possible.”

No matter the quality of steel you receive on your loading dock, however, the proper pretreatment equipment and processes must be in place to finalize preparation of your substrate for powder coating. This is where one of MPE’s suppliers became a crucial partner in evaluating and improving their processes.

Time for an Upgrade
In 2019 MPE began looking for additional opportunities to reinforce their production funnel with overflow work from other facilities. They learned a client had quality and Production Part Approval Process (PPAP) needs but unfortunately MPE didn’t have all of the data collection and tracking processes in place to take on the additional work. Although they are an FDA registered facility and have their ISO 9001:2015 and ISO 13485:2016 certifications in place, their system was simply more conventional and not designed for the stringent performance and reporting standards their client required. MPE engaged their suppliers to assist with planning equipment upgrades and improve their green and LEAN manufacturing methodologies even further.

One of the biggest chunks to bite off for this project was their legacy iron phosphate pretreatment system. They leaned on Chemetall, the Surface Treatment global business unit of the Coatings division of BASF, operating under the Chemetall brand. “Chemetall laid out the framework for changes to our existing conventional wash system to convert to a zirconium-based advanced pretreatment technology. They outlined changes needed to the washer that included adjustments to risers/ headers, nozzles, and adding and subtracting risers where appropriate.” Considerations for new reverse-osmosis and advanced media filtration systems were also critical for the project. “Reverse-osmosis systems are crucial for high performance coatings,” Jeff explains. “Most people think water is water, but the reality is, it’s not. In the Midwest, water quality varies significantly.” He adds with a laugh, “Water can be liquid rock in some areas of Wisconsin.”

MPE also worked closely with powder manufacturer AkzoNobel Powder Coatings to ensure their powder formulations would meet their client’s requirements. “We normally have around 150 medical grade powders on hand that we spray,” Jeff says. “Generally, the most collaboration we have with our powder suppliers is regarding antimicrobials or color matching.” Jeff goes on to explain that their OEM clients are very meticulous about color matching their furniture and equipment to be consistent with décor or other furnishings hospitals may already have in place. Their OEM clients also want their branding on their products, but labels can’t be used. Any recess or edge has the potential to collect germs, so MPE silk screens their clients’ branding on their products.

The Moment of Truth
After several months of planning, the project kicked off in November 2019. Jeff estimates the upgrade of the pretreatment system, from draining and cleaning the existing tanks, to installing the RO system, new pumps and monitoring, new spray nozzles etc., only lasted a few weeks total. “Brian [Groubert, chemical engineer for Chemetall] and the Chemetall team did most of the work and trained our staff on maintenance and operation,” Jeff shares, adding, “we couldn’t be happier with the transition.”

With the introduction of a new data collection and monitoring system, MPE became a completely paperless factory. Smart work orders are scanned into the central database and used to track parts through the finishing process. Masking instructions appear on a big screen TV for workers to follow. The entire chemical process is now automated, monitoring all five stages of the pretreatment line in real time. Every five minutes a timestamp is created, and all data points collected are fed into the database. MPE staff can now return to a work order and see exactly what happened to a part at specific times throughout the process.

Chemetall also helped MPE staff program soft and hard limits for the five-stage pretreatment system. Soft limits indicate when an action is taking place and starting to get outside of optimal parameters; a hard limit hit means an action needs to take place—such as pH level adjustments—and the system performs those adjustments automatically.

Jeff says the guidance provided by Chemetall allowed them to pass the stringent finishing standards of both medical and non-medical OEMs on the first round of testing. Currently, approximately 80% of their work is for the medical field. They coat neonatal incubators, imaging devices, infant eye care devices, carts that carry radioactive isotopes into CT rooms, surgeon consoles, and other specialized carts and devices.

When asked if their medical customers have the most stringent specifications and precise processes, Jeff posits some of their diversified industrial customers have even more stringent specifications. For example, some equipment they powder coat is used in salt mines, one of the most corrosive environments one can imagine.

MPE has been looking ahead to more facility upgrades in the future, including the addition of robotic sprayers and a batch booth for items that are too heavy or can’t make a turn on their line. They are also undertaking an internal quality improvement project to study the potential of using at least some reclaimed powder for their medical powder coating work. MPE reclaims powder for their diversified industrial customers, but has historically had to use virgin powder for medical applications to meet specifications. The project is still in its early stages, so the jury is still out on whether it will be possible. With a strong vision for the future, MPE seems to have what it takes to produce a high-quality powder coated finish for the medical industry and beyond.

Troy Newport is publisher, Powder Coated Tough.