Packaging Robots Make Major Inroads in CPG Industry

Aug. 29, 2014
Whether they’re palletizing cans of automotive liquid and powder coatings or assembling hundreds of packages of mini gummi snacks per minute, robots are more appealing than ever to CPGs looking for greater packaging line speeds, reduced labor costs, and increased accuracy and efficiency.

Whether they’re palletizing cans of automotive liquid and powder coatings or assembling hundreds of packages of mini gummi snacks per minute, robots are more appealing than ever to CPGs looking for greater packaging line speeds, reduced labor costs, and increased accuracy and efficiency.

This year, PMMI—the Association for Packaging and Processing Technologies—released results from a survey on consumer product manufacturers’growing use of robotics in the packaging plant. The “2014 Trends in Robotics Report” identified seven developments in robotics technology that are strengthening the business case for their adoption:
• Advances in vision sensor technology;
• Innovations in end-of-arm tooling (EOAT);
• Integrated robot controls;
• Improved sanitary designs for direct food contact;
• Faster operating speeds and increased lifting capabilities;
• Safety autonomy; and
• Decreased costs.

Case histories bear out PMMI’s observations. At Trolli GmbH, vision technology speeds the packaging of multi-component gummi treats; and at Axalta, integrated controls allow for ease of programming and troubleshooting. These are just two of many case histories in Packaging World’s annual Robotics & Automation Special Report—a two-part gathering of machine-builder case histories and automation innovation focused on packaging machinery of all kinds. (Part I appeared in August 2014,and part two appears in the September 2014 issue.)

Fürth, Germany-based Trolli, a part of the Mederer group of companies, produces sweets such as gummi candies, marshmallows and soft licorice gums. Since the 1980s, one of the company’s most well-known products has been the Trolli Burger, a gummi candy made of several layers of fruit gum and sugar foam created to look like a hamburger on a bun. In May 2013, Trolli began operation of a new packaging line from Gerhard Schubert GmbH to automatically assemble and package a smaller version of the product—the Trolli Mini Burger—at 540 items per minute.

Loosely stacked in a hinged plastic tray, the three parts of the Trolli Mini Burger—the bun, the cheese and lettuce, and the burger and bun—are organized in a set order and orientation. To accomplish the required speed of 540/min, 1,620 individual candy pieces must be assembled into the plastic trays. Schubert has achieved this level of output with its TLM-F44 packaging line. In this case, the line comprises 17 submachines and features 18 TLM-F4 four-axis pick-and-place robots as well as a number oftwo-axis TLM-F2 robots. The packaging line integrates two Transmodule sections, one of which is a 30-meter rail section— the longest implemented by Schubert so far. The patented TLM Transmodule is a single-axis, rail-based robot with contactless energy and data transmission. A turning unit is located at each end of the rail section that enables unloaded modules to travel back to the other end on the lower track. On Trolli’s 30-meter rail section, 30 Transmodules transport the trays to the picking area and then on to the closing station. The second rail section carries the closed trays to an ultrasonic sealer. Individual Transmodules move autonomously, with a Transmodule moving cyclically to set down a tray. Multiple Transmodules then group together and act as a continuous chain conveyor for the pick-and-place process. Once the trays are filled, the individual Transmodules separate and transition back to a cyclical motion for removal of the trays. The result is high flexibility in a small space. The first two submachines each contain a multi-lane magazine with plastic trays. The associated TLM-F3—a robot equipped with a suction or gripper tool designed specifically to remove materials from a magazine—removes trays and transfers them to a TLM-F2 robot, which places them into the tool of a Transmodule. The tool takes two rows of 12 cups each. The Transmodules then move to the picker stations as a group, where the first three product belts feed the bottom piece of the Trolli Mini Burger. This is followed by three product belts each for the middle and top pieces. The feeders are arranged crosswise to the line. Scanners record the position, rotary orientation, and bottom or top surface of the fruit gums. TLM-F4 robots pick up the products. If the correct side is facing up, the robot places the product directly into one half of the plastic tray. If a burger element has to be turned, the product enters a turning unit immediately next to the product belt. Once the element is turned, it can be removed by the picking robot. The fruit-gum burger is complete at the end of the picker line, where the bottom and middle pieces are in one half of the tray, and the top piece is in the other half. The Transmodule then moves the trays to the closing station. There, a TLM-F2 robot removes a row of plastic trays and places them onto a table, where they are automatically closed. Another TLM-F2 robot then removes the packages and places them onto their sides intoa size plate of a Transmodule on the second rail section. The compartments of the tool hold the plastic tray closed.

During further transversal, each individual plastic tray receives a label from a Pago labeling system and is then printed with a batch number using a Wolke coder from Videojet. The code is then inspected by a Cognex camera system.

Closed, labeled trays are then removed from the size plate and are transferred to the sealing unit. To seal the trays, Trolli uses an ultrasonic system that provides a reliable seal, while ensuring ease of opening for consumers, despite the tray’s small tab. After sealing, a two-axis robot grips the packages and places them onto the discharge belt. The finished products then run through a checkweigher, followed by a metal detector.

Trolli CEO Herbert Mederer appreciates the high degree of flexibility afforded by TLM technology. A larger version of the Trolli Mini Burger and a Trolli Pizza have also been assembled and packaged on the new TLM line. “The Schubert line is accompanying our growth and gives us freedom to innovate,” he says. “We’re planning on making additional investments overseas.”

PLC robot control

For Axalta Coating Systems, headquartered in Philadelphia, the use of integrated robot and programmable logic controller (PLC) controls for the first two robots in its Front Royal, Va., facility provided the flexibility and ease of programming needed to help facilitate its transition to a new packaging automation system.

Axalta is a global provider of liquid and powder coatings for auto-architectural and decorative applications, with 35 manufacturing centers, seven R&D facilities, and 42 customer training centers around the world.

In late 2012, when the company began specifying equipment for a new can-filling line at the Front Royal plant, it turned to Intelligrated to supply empty can depalletizing and case palletizing equipment. Recalls Sam Saleh, sales engineer for Intelligrated, “We were asked to take a look at this in a conventional palletizing way. But, because of space constraints, eventually it evolved into a robotic palletizing operation.”

According to John White, electrical and controls engineer for Axalta, space had never been a challenge for the 30-year-old Front Royal plant before, so conventional palletizing and depalletizing were the norm. “However, this new line was designated for an area with restricted space, so robotics became a viable alternative,” he says.

Among the requirements for the new systems were flexibility to handle a range of can sizes and case weights; operating speeds in excess of the line’s filler speed (proprietary); and elimination of silicone in the robots’ EOAT. As White explains, car paint does not react well with silicone, so all of the system’s pneumatic, vacuum and blower components and can-handling surfaces had to be silicone-free.

In addition, White says, Axalta was very focused on having “a high-reliability machine, with minimal operator interface so that the operators could spend their time interfacing with the actual filling operation.”

To meet Axalta’s needs, Intelligrated installed two Yaskawa Motoman four-axis MPL300 robots, featuring a 300 kg payload and fast axial speeds and acceleration that reduce cycle times and increase production output.

Notes White, the key advantage of the systems is the way the controls are designed. “The systems take advantage of the MLX100 robot control platform from Motoman that provides an interface between the robotics control system and the PLC so that all of the programming can be done on an Allen-Bradley system using RSLogix software—instead of having both a Yaskawa interface and an Allen-Bradley interface for technicians to handle,” he says. “It just makes the troubleshooting easier for our technicians, who are familiar with the Allen-Bradley platform.”

With a traditional robot controller, programming and control of the robot is done with a proprietary robot language—in the case of Motoman’s DX100 controller, it would be INFORM (Instructions for Motoman)—while the rest of the peripheral equipment is programmed and controlled through the PLC.

“With MLX100, the system becomes much more maintenance-friendly, and easy to use and debug in case of any problems,” White says. “It also allows for a significant level of flexibility in our safety control system by using Allen-Bradley’s safety-rated PLC. We can have things shut down and start up in the way we want. It makes it easier for our operators, while still maintaining the level of safety that we need.”

Also suited to Axalta’s requirements, Saleh explains, is the depalletizer’s ability to initialize depalletizing of a partial load or partial layer of cans with the layer handling tool, to minimize waste in packaging and assist operators with container size changeovers. The robot uses a vacuum EOAT designed by TEPRO, while a clamp tool from Intelligrated is employed for the case palletizer.

Since installation in August 2013, the few problems encountered have been primarily related to the operations and support personnel’s learning curve, says White, and they have been “quickly and professionally” addressed by Intelligrated. And, he adds, the installation has provided the hoped-for hands-off operation. “The two robotics systems together have less operator interface than any other pieces of equipment. They just sit there and run.”

Axalta now has a growing appreciation of robotic systems capabilities. “Robotics is a resource we will continue to leverage for future manufacturing applications,” says White. “Robotics is a resource we will continue to leverage for future manufacturing applications,” says White.