Palletizing applications pile up for robots: robots, faster and cheaper than ever, can be competitive in many more palletizing applications than befor

When it comes to the end of the line, robots may be the end of the line.
Traditionally, robotic palletizing has been viewed as an intermediate step between strictly manual and fully automatic. For a robot to make sense at the end of the line, the application had to be low-volume and/or highly variable, with shifting pallet patterns that required great flexibility.
That's still true, of course. But reliability and other factors have improved in robotic palletizing systems to the point where, in some applications, they can compete directly as a alternative to fully automatic ram-based systems.
End users who are moving away from manual palletizing often have to choose between robotic and traditional palletizers. That's the choice faced by English Mountain Spring Water, Dandridge, Tenn., which supplies the Cracker Barrel restaurant chain with water in customized polyethyelene terephthalte (PET) bottles for diners and store customers.
English Mountain considered a conventional palletizer, but settled on a KR 180 robot system from Kuka Robotics, installed by Aidco International. The robotic system was only about $10,000 more than the conventional one, and offered more versatility, says company president John Burleson.
We felt that down the road, we could actually take [the robot] and put it anyplace in the plant and maybe even retool it to do some additional work," Burleson says.
Robotic future
Palletizing is "going away from hard automation and going more and more toward robotics," asserts Matthew Job, senior engineer for material handling, palletizing and packaging at Fanuc Robotics.
Robots can compete on equal terms with many conventional palletizers because they're more robust. It's not uncommon for a robot to be rated at more than 60,000 hours of mean time between failures.
"You look at a hard automation palletizer, there's drives and chains and pulleys and many different things that can break," Job says. "In a robot there's four motors and four [speed] reducers and beyond that, it's all linkage, so there's very few things that can go wrong."
FKI Logistex markets both robotic and conventional palletizers. Pat O'Connor, the company's product manager for palletizing systems, says the competition between the two has become more direct.
"I would say there is no question that robotic palletizers compete head to head with conventional ones," O'Connor says. "I think customer preference or customer fascination with the technology sometimes encourages the use of robots where conventional palletizers could be less expensive."
In some applications, robots compete by moving cases just like conventional palletizers do: in entire layers at a time. Kevin Alberts, regional sales director at Brenton Engineering, says some customers use robots to replace worn-out conventional palletizers. Such robot systems usually have layer-forming tables and robot end-of-arm tooling that allow it to pick tip and move a whole layer of cases.
"Application-wise, it's almost similar to a [conventional palletizer]," Alberts says. "We would still form a layer pattern and pick and place that pattern. With that, we have seen rates approaching--or exceeding, with small cases--100 cases a minute." End-user benefits can include a low-level case infeed, a flexible system footprint to fit existing room layouts, robot reliability and the flexibility to quickly adapt to product changes through user-friendly software.
O'Connor says FKI Logistex has had similar installations, but he doesn't believe that it represents the future of robotic palletizing.
"I think that over the long term, direct pick-and-place will be the solution, and not combining some alternate technology to try to get the robot to speed up," O'Connor says.
Flexibility advantage
Robotic palletizing still retains its traditional advantages. "The underlying advantage we have over any hard automation is flexibility," Job says.
The most common need for flexibility in palletizing stems from the need to change pallet loading patterns. Retailers are demanding a greater variety in both case sizes and load make-ups. Many retailers want what Kevin Kozuszek, marketing manager of Kuka Robotics, calls "rainbow loads," consisting of numerous product types.
Robots, of course, can handle this kind of variety much more easily than conventional palletizers. With the latter, changing a pallet pattern is a major mechanical project; for robots, it's a simple matter of programming.
How simple is a factor that varies among suppliers. Most of them provide the initial programming but allow end users to add new patterns as needed. In most cases, such programming would have to be done by electricians or other trained plant personnel. But some robot manufacturers are touting systems that allow pallet pattern programming through the operator interface, presumably by anyone on the plant floor.