ProMach Filling System Boosts Weight Measurements
Using EtherCAT and PC-based automation from Beckhoff, ProMach Filling Systems' new XACT-FIL packaging machines enhance accuracy and efficiency while reducing footprint 30%
Two or three peanuts may seem like a trivial amount, but to food companies producing thousands of canisters of snack nuts each day, the cost of every pecan, cashew and almond can add up quickly. To protect the bottom line for end users, machines used in the food packaging industry must not only be sanitary and reliable, but also extremely accurate. One instance of this, recalls Cezary Mroz, vice president of engineering for ProMach Filling Systems, was when a customer demanded extreme accuracy for a machine that filled containers with nuts.
“This continuous motion machine filled containers with 3 pounds of nuts. The containers came off a scale, and the customer wanted an accuracy by weight of half a nut,” he says, adding that they eventually settled on an accuracy of one. “The challenge here was that we didn’t have a nut cutter.”
Meeting customer demands while adding functionality led ProMach and its Federal product brand to introduce the XACT-FIL™ machine line in 2017. ProMach encompasses a family of more than 30 packaging machine product brands serving manufacturers of all sizes in the food, beverage, pharmaceutical, personal care and household and industrial goods industries. ProMach brands operate across the packaging spectrum, but Federal primarily designs and manufactures filling and capping systems. The history of Federal dates back to 1946, before the Waukesha, Wisconsin, company joined the ProMach family in 2012.
As an important addition to the comprehensive range of ProMach solutions, the XACT-FIL is a multi-model line of next generation weight fillers. XACT-FIL machines use a feed screw to load containers onto a carousel. The machines support high-density polyethylene (HDPE), polyethylene terephthalate (PET), metal and glass containers as small as 1 ounce and as large as 5 gallons. Next, a filling turret dispenses liquid food products, such as hot sauce, milk and olive oil, and non-food products, including paint, chemicals and automotive lubricants. Different models support hot, cold and ambient fill operations.
Scales throughout the machine measure the weight of a container thousands of times per second, providing a fill-weight accuracy of plus or minus half a percent — or better. Then the container moves to the capping turret to be sealed. Because the XACT-FIL line offers greater versatility than previous systems, ProMach engineers had to upgrade to new automation and control technologies capable of supporting a faster and more reliable machine.
ProMach's mission to reduce machine footprint and increase efficiency
Beyond the typical challenges of creating efficient and accurate weight filling systems, ProMach engineers needed to minimize space requirements and the number of cables when designing the XACT-FIL. Space constraints have always been a concern in plants and factories, but in recent years, every square inch of footprint eliminated makes a system more competitive. Of course, reducing the number of cables corresponds with the smaller footprint trend. In the food packaging industry, having fewer cables also promotes improved hygiene. Food packaging machines require regular, thorough cleanings, so fewer cables reduces the burden to maintain a sanitary environment.
“More cables also create more entry points for equipment failure, so a single cable to run a device is better than two,” Mroz adds.
Coordinating the machine’s rapid yet precise loading, filling and capping sequences requires powerful automation, motion control ad I/O systems. In addition, all hardware and software must communicate with the utmost precision, as high quality, non-contact filling is one of the machine’s main selling points. In this process, the liquid never touches the container above the fill line or the exterior of the nozzle, which prevents liquids from dripping on the outsides of containers and keeps the machine clean.
“With non-contact filling, the nozzle hovers above the opening, usually about a quarter of an inch,” Mroz says. “Strict attention to hygiene and avoiding cross-contamination is critical, so non-contact filling is simply the cleanest approach.”
All of these considerations created a tall order for ProMach, and Mroz and his team did not have time to waste. The XACT-FIL project had a firm deadline: The machine needed to premier at Pack Expo 2017, but at the beginning of the year, they still had not finalized the design. However, Mroz believes that innovative thinking and the right technologies create ideal solutions: “If somebody says it can't be done, my response is, ‘Well, then you haven't been thinking creatively.’ Control technology is not the limiting factor.”
Have your fill of innovative automation
With the XACT-FIL deadline looming, Mroz and his team turned to Beckhoff Automation in February 2017. The ProMach engineers worked extensively with Beckhoff sales and support engineers, and even travelled to the company’s U.S. headquarters in Savage, Minn., to test the weight filler prototype. The application support that Beckhoff provides to customers on-site and over the phone sets the company apart in the industry, according to Thomas Retzlaff, Wisconsin area sales manager for Beckhoff. “For the engineers at ProMach to get this level of service from other vendors, they would have to purchase an expensive support contract,” Retzlaff says. “This factored into their decision to utilize Beckhoff solutions in the XACT-FIL design.”
Soon, Mroz and his team at Federal designed a system that uses a Beckhoff CX5140 Embedded PC with a four-core Intel® Atom™ E3845 processor. Mroz explains that the embedded PC’s dimensions of 142 mm x 100 mm x 92 mm quickly reduced cabinet size: “When many people see the CX embedded controller, they ask me, ‘Where’s the rest of it?’ It’s exceptionally compact and powerful, which is exactly what we needed.” This helped ProMach improve the reliability and throughput of the XACT-FIL, adds Kurt Schneider, applications engineer for Beckhoff.
“Beckhoff continues to increase the processing power of its entire line of PC-based controllers to ensure that customers do not face any limitations when working with our portfolio of solutions,” Schneider says.
The CX5140 runs TwinCAT 3 automation software, and Mroz appreciates that the open hardware platform also runs any add-on software that works on Windows and easily communicates with legacy systems. Mroz explains that the benefits of TwinCAT became more apparent due to its unique runtime licensing: “Our original project included our base PLC and HMI programs, and we thought that would cover all of the machine functions. However, as the project grew, we needed to include motion control. A runtime license was simply added to make the application ready for motion. It’s nothing more than electronic keying.” As a backup, a CFast card programmed with all PLC and motion control projects for the XACT-FIL ensures that even if the machine encounters a problem, the machine can continue to load, fill and cap containers with a quick swap of the solid-state media if needed.
Machine operators control and monitor XACT-FIL units via a Beckhoff CP3918 control panel, which boasts a 19-inch touchscreen and multi-touch functionality for advanced HMI. This stainless steel model is mounted to a pole beside the filling turret, making it easy to see the screen and monitor the machine functions at the same time. “The multi-touch panel is very sleek and simple, and the resolution on the screen is brilliant as well,” Mroz says. “Beckhoff offers multiple multi-touch panel form factors that work with the scalable HMI software options to provide solutions for any screen size and performance level we need to implement.”
For motion control hardware, ProMach selected Beckhoff AM8841 servomotors to operate the filling turret, capper and feed screw. These stainless series servomotors on timing screws reduce the amount of torque needed and support IP69K wash-down environments. The final design boasts a unique lubrication and vibration-free Accu-Cycloidal™ gearing system developed over many years by ProMach.
Mroz found that AX5000 series servo drives with built-in mains filter and regen capabilities from Beckhoff provided compact hardware to implement the three-axis motion system: “With other drive vendors we tested, we would have had to use a wider servo drive form factor meaning the doors wouldn’t close in the compact enclosure we used in the XACT-FIL to maintain small machine footprint. However, the AX5000 servo drives are very narrow and fit perfectly.” In addition, one cable technology (OCT) provides power and feedback signals to the motors through one cable, further reducing footprint.
Serving as the drives bus and the I/O system, EtherCAT industrial Ethernet communication facilitates real-time communication while further minimizing form factor. Retzlaff says the high-density 16-channel HD EtherCAT Terminals proved especially helpful in reducing footprint: “Rotary fillers have considerable space constrictions, so the incredibly compact HD terminals are perfect for this application.” It is especially important with non-contact filling to ensure that each container is handled with great accuracy and each machine component activated at precisely the right time.
Mroz explains that the real-time networking capabilities of EtherCAT eliminate common mistakes on the production line: “EtherCAT delivers by far the fastest, most widely adopted industrial protocol available in terms of device variety.”
Weight-filling system tips the scales toward success
Ingenuity on the part of ProMach, combined with PC-based control solutions from Beckhoff, created an extremely fast, versatile and easy to use weight-filling machine geared for the demanding packaging marketplace. While providing a design just as durable and hygienic as previous ProMach solutions, the XACT-FIL reduced its required part count by 25% and overall machine footprint by 30%. In addition, EtherCAT roughly quadrupled the number of weight measurements per second, increasing it from 1,200 to 5,000.
“EtherCAT and TwinCAT allow the valve output I/O and the load cell measurements to be synchronously scanned with the PLC code cycle time of 200 microseconds,” Schneider says. “This provides tighter overall valve response and accuracy.”
The ProMach and Beckhoff engineers completed the first XACT-FIL in time for Pack Expo 2017, and in addition to shrinking size requirements and using open platform PC-based controls, the machine provides a plug-and-play solution. This was something Mroz always wanted to accomplish but was unable to do so until partnering with Beckhoff.
This showcases the flexibility of Beckhoff technology in creating a modular weight-filling system, according to Retzlaff. “Beckhoff focuses heavily on R&D for new technologies. As a result, we were able to equip ProMach with the best, innovative solutions in automation and controls to perfectly fit this application and others,” he says.
Mroz believes there are no limitations to what PC-based control technology and a can-do mindset can accomplish. However, it is easier for ProMach, as an international company, to build and sell equipment when its automation and control technology vendor can provide components and support worldwide.
“We have experienced many advantages due to cost savings and the quality of the technology itself, but another benefit is that Beckhoff is a global company,” Mroz says. “Because we can get support wherever and whenever we need it, I’m not losing any sleep worrying about whether a machine will power up tomorrow or the next day. Beckhoff has harnessed all the benefits of PC-based systems to help us provide a reliable, highly accurate and internationally recognized weight-filling solution.”
Are you interested in enhancing your new machine designs with PC-based automation? Contact your local Beckhoff sales engineer today.
James Figy is the Senior Content Specialist for Beckhoff Automation LLC.
A version of this article previously appeared in Packaging World.