Marlen's DuraKut size reduction equipment

The old way of designing food processing and packaging equipment was for OEMs to take the reins, designing and testing the equipment in-house without involving customers in the process.

But the old way doesn’t work anymore. Processors face a growing list of challenges — food safety concerns and employee turnover, to name just a few. To meet these challenges, they need equipment that’s hygienically designed and easy to use, even for operators who might never have encountered the equipment before. 

Developing this equipment requires OEMs to seek out extensive customer input and to allow the design process to be guided by customer feedback and insights gathered from in-plant testing. “Our customers are running millions and billions of pounds of products. They're seeing things we can’t,” says Doug Wilson, director of engineering at Marlen. “Without that valuable customer feedback, you're designing in the dark.”

Marlen adopted this highly collaborative approach to create their new DuraKut size reduction equipment and OptiServ vacuum stuffing and pumping system. We spoke with Wilson to learn more about the process and how the resulting equipment sets a new standard for hygienic and user-friendly design.

The process: A whole new level of collaboration

When Marlen decided to redesign some of its equipment, the first thing they did was invite several customers to their facility for a voice of the customer event. “We took a full day to go through the designs and ask for opinions about what they liked, what they didn't like, and what's missing,” Wilson says. 

They also spent time talking with the clients who were investing the most in improving food safety about the challenges they encountered along the way. For example, one client had taken nearly 200,000 swabs to pinpoint the source of bacteria on their equipment. These conversations helped Marlen’s engineers understand where food safety problems were most likely to occur and eliminate these risks via sanitary design.

Once they had equipment that checked all of the boxes on paper, Marlen sent the machines to a customer’s facility to test drive them in a real-world processing environment. They gathered data on things like power consumption, product quality, yield loss, amount of fines, and disassembly time, and had the customer assess the equipment from a hygiene standpoint.

Marlen also watched how operators and maintenance technicians interacted with the equipment, which was sometimes quite different from what the engineers intended. Wilson gives this example: “If something is a foot off the ground and sticks out from the machine, it becomes a step. Engineers don't think that way. They think it’s a bracket that’s meant to hold the sensor. But for plant operators, if it's located at that spot, it’s a step.”

Based on what they learned during the testing process, Marlen made some adjustments to the equipment. The result, Wilson says, is machines that “pass or exceed every checklist of customer expectations.”

The results: Industry-leading design innovations

Here are the innovations that Marlen has brought to market with the DuraKut and the OptiServ.

Enhanced sanitary design

Even though sanitary design is one of the hottest topics in food processing equipment circles today, Wilson has noticed a general lack of understanding about what it means. “There's not a good design standard out there,” he says.

To help customers better understand this critical issue, Marlen is developing its own guidelines based on practical machine use and customer performance standards. This framework involves thinking of equipment differently comprising four zones. Zone 1 is the areas of direct product contact, Zone 2 defines areas above or near the product, and Zones 3 and 4 are parts of the machine’s frame, located farther away from the product.

Marlen created their initial designs based on this framework, with Zone 1 as the primary focus. “That zone should have little to no fasteners or laminated surfaces,” Wilson says. It’s also free of flat surfaces where water or bacteria can pool. “A true sanitary design means the machine exists with all angles.”

Once they had the design, they took it to their customers and asked if they saw any problems. Then they built a machine and sent it to a customer’s plant for testing.  “We had their entire sanitary engineering crew work the machine over,” Wilson says.  

The customers identified a few tweaks that needed to be made, such as some flat areas that needed to be angled and a bearing cover that caused a potential concern. “We fixed those issues immediately,” Wilson says. “We designed more fixturing to assemble the machines without flat surfaces, and we even came up with a better method of calculating the potential bacteria harborage.”

Marlen also realized that they needed to provide better training on how to properly clean the equipment. “We have some customers that use very high pressure,” Wilson says. This may effectively rid the machine of contaminants, but it’s “essentially atomizing the bacteria into the air so that it literally floats around the building and lands on the equipment you just cleaned.” 

Using hot water (over 140 ℉) is also important, especially when working with fats and other greasy materials that cling to the equipment. “It's just like your dishes at home. If you clean them with cold water, you can’t get most of the stuff off.”

Tool-less, faster disassembly

The cleaning discussions led straight to talking about the ease and speed of disassembly. When sanitation staff has to break down and clean equipment once or twice a day, downtime becomes a concern. So, Marlen reduced the number of components on the machines and eliminated the need for tools, thus speeding up disassembly and reassembly. “It’s a huge difference if you have to take off five parts instead of 50, or if you can just turn a knob or flip a latch instead of using a wrench,” Wilson says. 

As an illustration of this point, the new OptiServ has 300 fewer parts than its previous version, taking just under 3 minutes to assemble/disassemble instead of 25 or 30. Fewer components also means fewer areas where problems can occur. “Before, the Opti pump had one-third more components on it,” Wilson says. “So there were one-third more things that could go wrong.”

A simplified human-machine interface (HMI)

Talking about cleaning crews in turn led to talking about workforce challenges. This conversation produced one of Marlen’s most important, and most innovative, design changes.

One of the first things the company learned at the voice of the customer event was that the HMI wasn’t ideal. There was a language barrier preventing employees from operating the equipment properly. And even though the interface language could be switched between English, French, and Spanish, it was impractical to keep changing it for the various operators. 

“That steered us in a different direction,” Wilson says, “which was to design an all-icon based HMI.” Using internationally-recognized ISO symbols instead of words, the updated interface walks employees through how to take apart the equipment. “We took all the CAD models used to produce the machine and put them right into the HMI so the operators can see the steps to take the equipment apart and put it back together.” 

This change also helps orient new employees to more quickly prepare the machine for the sanitation process, something that’s becoming increasingly important as employee turnover intervals become shorter. Some of Marlen’s customers report a complete changeover of their sanitation staff every 3 to 6 months. 

The new HMI simplifies the process of training new employees and makes operating the equipment easy. “We only display what needs to be displayed at the moment,” Wilson explains. “An operator can easily start the machine, load a recipe, wash the machine, and put it back together.” 

This new HMI has made a huge splash in the industry. “I didn't realize how big of a deal it was going to be,” Wilson says, “but it’s been revolutionary because it’s so different from anything else that’s available.”

Electrical boxes that don’t leak

Another sanitary issue that’s widespread in the industry is the ease with which water and bacteria get into electrical boxes. “By nature, they have a gap all the way around them,” Wilson says. “There's a gasket inside that seals it.” But those seals don’t hold up well in the harsh environment of a food plant. Wilson notes that even though many of the products on the market have a NEMA 4X rating, “we've tested many of them to leak at a lower pressure.” 

The current solution for most companies is to install the boxes far away from the machine. That means they have to connect the boxes to the equipment with cables, risking the possibility of disconnection, increased troubleshooting time and machine shutdown.

Marlen knew they could build a better box, and they did. “We embarked on a project to build a box that’s sanitary and doesn’t leak,” Wilson says. “We were able to get the commercially available boxes to leak at 80 psi with a ¾” hose. We’ve tested the new box at 2,000 psi and it doesn’t leak even with direct spray on the seal. That's a big thing for not only sanitary design but also for the functionality and safety of the machine.” This will also reduce costly electrical component failures resulting in downtime. The new box is now available on all of Marlen’s new machines. 

Better energy efficiency 

The new equipment also uses far less power and water. The OptiServ, for example, is no longer a hydraulic system but rather is servo-driven. “At any one time, there's a servo accelerating and another servo decelerating,” Wilson explains. “We bussed the drives together to provide a network between them, so the motor that's accelerating can use up the energy of the one that's decelerating. Many people know this as regenerative braking, much like electric cars today.” 

In making this change, Marlen has tested at customer sites showing a 40% reduction in power consumption.

Improved precision

Finally, Marlen improved the precision of the new machines. “With the latency in hydraulic valve shifting and starting and stopping, it was very difficult to get higher levels of precision in the old Opti model,” Wilson explains. “The new OptiServ piston control is down to 1,000th of an inch. “That’s one-third the thickness of a human hair. That precision level gives us the ability to do things that we weren't able to do before.” 

The DuraKut went through its own share of modifications, reducing the gap between the blade and upper conveyor from about ¾” to ⅛” and adding a feedback mechanism. “We can now accurately control the amount of pressure we put on the product,” Wilson says. “And it articulates side-to-side so that it maintains equal pressure across the belt width.”

In practice, this translates into more precision. “Chicken breasts are the perfect example because they’re all different heights and there’s a thick end a thin end,” Wilson says. “Many plants don't orient the product, they just pour the product on the conveyor because they're trying to get high throughput. In the dicing process, what allows you to have a really good dice on a variable product is the ability to have tight controls holding the product while the knife is cutting through it.”

Marlen has been an innovation leader in the food processing space for decades. The newest evolution of their equipment proves that they continue to earn that distinction.

To find out more about Marlen’s design process and the new DuraKut and OptiServ machines, check out Booth #2049 at PROCESS EXPO.