A KR QUANTEC robot depalletizes high stacks of beer crates for Widmer Brothers Brewing. (video: KUKA)
The Craft Brew Alliance (CBA) is an American independent and publicly traded regional brewery created through the merger of the leading breweries along the US Pacific Northwest coast:
Redhook Ale Brewery
Kona Brewing Company
Since then, CBA has offered the beer varieties developed by all three breweries under a single roof. The craft beers from Widmer, the lively Hawaiian island brews from Kona, along with the brands from Redhook are very popular in the USA and boast a number of awards.
Innovative processes + innovative breweries = innovative beers
However, the breweries do not simply just offer popular and innovative beers. They also have cutting-edge production systems and innovative processes. As part of this, Widmer Brothers Brewing has recently acquired an industrial robot from KUKA. The six-axis robot from the KR QUANTEC series is tackling the unloading of beer crates at the brewery, located in Portland, Oregon (USA).
A new solution was needed to handle the increasingly shorter cycle times
As demand for the Widmer product increased, so did the production requirements and the associated work steps (such as packaging and palletizing the beers). not only, volume and speed mattered, but precision as well.
The previous bottle depalletizer at Widmer Brothers Brewing was a semi-automated system that was no longer able to handle the increasingly shorter cycle times – which slowed depalletizing operations and led to productivity losses.
Safety is the driver, KUKA KR Quantec unload the pallet
The biggest driver in a search for a new solution, was safety. “Unloading the crates by hand was problematic for safety reasons since the motion sequences are repetitive and caused injuries,” explains Rick Ginter, Director of Engineering at Widmer Brothers Brewing.
He notes that this made the work extremely tough and strenuous on the human body. An alternative had to be found. Beyond this, it had to be possible in the future to load the pallets to the full height and not, as was previously the case, just halfway.
A robot-based solution vs a conventional depalletizer
A conventional depalletizer was eliminated as a possibility from the outset due to the low ceiling height, the integrator and official KUKA System Partner Midwest Engineered Systems turned to a robot-based solution.
“The robot had to be able to move the upper layers of the incoming pallet load underneath an existing beam,” notes Ginter, explaining the challenge. The KUKA KR QUANTEC series robot selected by Widmer Brewing was programmed to easily avoid the beam and to unload the pallet stacked to full height. The decision to go with KUKA was based on experience: for seven years now, a KUKA robot has been working reliably on Widmers’ keg production line. “The robot has achieved excellent operating times there. Since then, maintenance and the ordering of spare parts have been kept to a minimum,” stresses Ginter.
Precise depalletizing process with short cycle times
At Widmer Brothers Brewing, the depalletizing process begins with the fork lift operator.
He places a load of bottles on the infeed of the five-zone pallet accumulating conveyor, at the end of which a pneumatic pallet pusher extends, sliding the pallet load across rollers.
At the end of the conveyor, the pallet enters the unloading zone of the robot and comes to a halt at the pop-up blade stop, where it is justified parallel to the direction of travel.
A pneumatic pallet pusher slides the pallet load over the rollers, thus justifying the pallet in the direction perpendicular to the conveyor flow. Using a universal vacuum gripper, the KUKA KR 270 R2700 ultra robot then positions itself above the top layer of the pallet load, takes the uppermost layer of cases from the pallet, moves to the layer separation conveyor and sets the layer down on the conveyor. This process is repeated multiple times.
The vision system in the process to verify the alignement
The layer separation conveyor meanwhile transfers one row at a time onto the case conveyor. The case conveyor pulls the cases away from the layer separation conveyor, this ensuring an appropriate gap between the cases. As the cases travel down the case conveyor, they pass under a vision system to determine whether they are aligned with the short or long side leading (and, if necessary, they are turned).
The case conveyor then leads in a spiral back towards the robot and upwards to the existing inclined conveyor. As soon as the robot is finished unloading the pallet, the pallet continues down the pallet conveyor, where it is placed on an automated pallet stacker and can be unloaded by a fork lift.
Flexibility is the trump card
The KUKA KR 270 R2700 ultra performs convincingly at Widmer Brothers Brewing through maximum flexibility and an ideal ratio of payload to reach. It easily lifts 270 kg and has a maximum reach of 2,700 mm.
Thanks to its six axes, it offers the agility to perfectly master the difficult installation situation due to the low ceiling height. It also scores points for its utmost precision in the loading and unloading operations.
As with all robots of the KR QUANTEC series, this model is characterized by up to 160 kg less weight and 25% less volume compared with its predecessor series. The lighter components allow greater dynamic performance and even shorter cycle times, as well as being stiffer than before.
20 percent increase in productivity
“Today, we can deliver all pallet loads for depalletizing at their full height and run at line designed speed. For our 12-packs of beer, this means a hefty increase of 20 percent in productivity,” sums up Ginter. Beyond this, cases no longer need to be unloaded by hand. Safety problems – such as employee back strain as well as joint and muscle injuries – have thus been eliminated from this part of the production process. “
We are very pleased with the integration by Midwest Engineered Systems and the KUKA robot; I would certainly use both MWES and KUKA robots in any future packaging automation products,” explains the Director of Engineering with an eye towards future solutions.