Palletizing and De-Palletizing Applications

Robotics have been a staple of manufacturing for decades. Improvements to end-of-arm tooling, software, and vision systems have pushed flexible robotics downstream of manufacturing to perform palletizing and de-palletizing tasks. Subsequent to manufacturing, robots also apply packaging and ready these packaged goods for transport by stacking assemblies onto pallets for distribution.

“I see exciting developments in logistics and distribution applications. Recent enhancements of software and gripping technology help assemble unique, custom built-to-order pallet loads of different size items,” says Richard Motley, Senior Account Manager at FANUC Robotics America Corp. (Rochester Hills, Michigan).

The proliferation of new packaging and the ergonomics of palletizing and de-palletizing jobs provides manufacturers and distributors increased incentives to deploy robotics. Palletizing and de-palletizing applications show promise for continued growth within the robotics industry.

From Hard to Flexible Automation
Conventional palletizing systems have dominated the market for decades but integrators see a trend moving towards robotics, says Terry Zarnowski, Schneider Packaging Equipment Co. Inc.‘s (Brewerton, New York) Sales and Marketing Director. “The biggest trend we see is a movement towards robotics from conventional palletizers. Robotic palletizers provide flexibility and the ability to palletize different stock-keeping units (SKU) with minimal or no change over. Existing conventional palletizers are aging and we have been getting more requests from our customers to replace conventional systems with robotics.” Conventional palletizers cannot handle multiple SKUs effectively.

Until relatively recently, Zarnowski says, a manufacturing line ran a dedicated product over the course of several years. “Now, we see much shorter runs of products that might be on the market for only a year or two. The manufacturer will change something about the product or it’s packaging to make that product more marketable to consumers.” Those changes require flexibility, a feature most old-style conventional palletizers lack, says Zarnowski. “Palletizing and de-palletizing applications have really taken off and is the largest growth sector of our business. We have shipped hundreds of robots for these applications in recent years.”

As conventional palletizers make way for robot-based palletizing and de-palletizing, the process is less centralized using smaller robots. “We see the decentralization of palletizing and much more end-of-line palletizing. We see the movement towards this configuration and a movement away from the traditional configuration that used bigger robots in large-scale palletizing work cells,” notes Rick Tallian, Consumer Industry Manager at ABB Inc. (Auburn Hills, Michigan). “This configuration allows end-users more versatility in system design and reduces material handling expenditures on equipment such as conveyors.”

New Packages for New Products
The inherent flexibility of robotics lends itself to the rapid growth in handling new packaging designs, says Earl Wohlrab, Palletizing and Robotics Systems Product Manager with Intelligrated Systems Inc. (St. Louis, Missouri). "Packaging types have changed quite a bit over the last several years. These new packages are increasingly difficult to handle. Packaging is moving away from rigid corrugate casing."

Wohlrab says more environmentally friendly packaging with more desirable graphics for consumers continues to impact the palletizing and de-palletizing market. "Those changes lead people towards robotics." The speed of robotics is always increasing and will soon rival conventional case palletizers when manipulating less rigid packaging, Wohlrab concludes.

Likewise, Thomas Herndon, General Manager at FIPA Inc. (Cary, North Carolina) speaks of future products wrapped in new packaging types that robots will be called on to handle. “New packing designs and new products have to be handled somehow. The people who design new packaging intended to catch a consumer’s eye are not the ones who design the machine that will pick it up. Packaging materials are changing, becoming more porous due to the use of recycled products. Consumers want green packaging.”

Herndon turns his attention to new pallet designs. “The pallets themselves have changed, with less wooden and more plastic pallets. New style pallets for frozen foods allow air circulation throughout to ensure the product on the pallet is frozen evenly.” Like new packaging designs, Herndon says developers of new pallets did not consider how plastic pallets will be handled. “Some plastic pallets are just a grate, which are difficult to grab by the edges if wedged next to each other.” These grate-like pallets cannot be grasped by vacuum grippers but require more complex expansion grippers for manipulation, Herndon says.

Traditional wood pallets can simply be lifted from the top by vacuum-actuated foam grippers, explained Herndon.

Similarly, Sridhar Karnam, Product Marketing Manager at Adept Technology Inc. (Pleasanton, California) talks about changing pallet configurations. “Pallets are getting smaller. Each production line is not only capable of processing parts but palletizing them for shipment. In the last few years, end-users have been asking for palletizing robotic systems for food packaging applications.”

Robotics and compliant end-of-arm tooling facilitate manipulating products not yet in production nor in the marketplace. “Robotics help in planning for the future for products not in the pipeline yet. We cannot imagine new products to be introduced in five years. Manufacturers need a tool able to handle those future products,” says Herndon.

Flexible robotics require flexible, adaptable grippers, says William Symanski, an Applications Engineer with Schmalz Inc. (Raleigh, North Carolina). “Universal tools are designed to handle a wider range of products and have better palletizing software. Distribution centers require multiple ways of gripping up to 20,000 SKUs. One tool is able to handle an entire pallet layer of products.”

Grippers must not only deal with a high mix of products that might change frequently, but also extremely irregular shapes, says Lisa Maitre, Senior Project Engineer with Kawasaki Robotics (USA) Inc. (Wixom, Michigan). “Advancements in the of flexibility of robot tooling for palletizing has greatly benefited palletizing applications. New styles of vacuum tooling using foam pads instead of suction cups makes possible the use of the same tool for a broad range of products, including non-uniform products.”

Load, Unload
Increasingly powerful vision systems play an important role in palletizing and de-palletizing applications, especially the latter, says Motley. “Vision plays a big role in guiding the robot in de-palletizing applications. The robot can de-palletize by layer or pick items individually.” Motley says while vision is also used in palletizing work cells, vision is less important due to products having a more well-known location through the use of conveyors and bar codes.

Tom Sipple, Material Handling Product Marketing Manager at the Motoman Robotics Division of Yaskawa America, Inc. (Miamisburg, Ohio) has a similar take on the function of vision in de-palletizing work cells. “Vision does not play much of a part in palletizing but is a big part of de-palletizing. When bringing in layers of product into a de-palletizing work cell, the vision system takes an image to locate products and guides the robot into the ideal position for de-palletizing.” Vision is a powerful part of the solution in de-palletizing applications, concludes Sipple.

Products often shift location on a pallet during transportation, making robotic de-palletizing more challenging upon arrival, points out Robert Rochelle, Food and Packaging Industry Specialist at Stäubli Corp. (Duncan, South Carolina). “Vision is a necessity in de-palletizing operations as product shifts in transit. Vision can eliminate the need for conveyor crowders or to sort a variable product mix on an in-feed sorting device.”

When building a mixed pallet, the robot’s software algorithm should take into account unloading sequences, says Sipple. “Robotic technology can deliver mixed product pallets, although the throughput is not as high as conventional palletizing systems. When putting mixed products onto a pallet, the robot software must consider many factors, such as the ideal unloading sequence, products subject to crushing, stability and how irregularly shaped products can be stacked.” To illustrate his point, Sipple warns against placing canned goods atop of bread.

Skill-Building
Robot users and integrators have several opportunities to educate themselves on palletizing and de-palletizing applications. Adil Shafi, President of ADVENOVATION Inc. (Houghton, Michigan) will conduct a one-hour webinar, Palletizing/De-palletizing-Robot Basics, beginning at 12:00 PM EDT on Thursday, May 24.

“The webinar will cover flexible tooling, hard tooling, mechanical, vacuum, vision and traceability. The webinar will show several application videos of how these things work,” Shafi said in previewing the webinar. “I will present a background of the topic of palletizing and de-palletizing, through application videos, a brief power-point presentation, and a panel discussion.” Shafi will tailor the webinar for both palletizing and de-palletizing experts as well as novices alike. The webinar will look at single product and mixed-load palletizing, order flow and fulfillment, throughput, among other subjects.

Players in the robotics market have another opportunity to find the latest and greatest products in palletizing and de-palletizing applications at Automate 2013. Automate, the premier trade show and conference for all things robotic, is co-located with ProMat at Chicago’s McCormick Place, January 21-24, 2013. These shows promise to be a one-stop shopping venue for manufactures’ automation needs.

“Schneider will show our newer palletizing products, including a high-level robotic palletizer. This system takes up minimal floor space and palletizes at very high speeds,” says Zarnowski. “The work cell is a hybrid of the best attributes of a high-level conventional palletizer and the best attributes of a robotic palletizer: flexibility, speed, compactness, and ease of use that our customers want.”

Several participating companies will have a presence in both Automate and ProMat. “Schmalz will have booths at both Automate and ProMat. We will show universal tooling, systems with a wider work envelope, to handle a wider range of products,” foretells Volker Schmitz, President of Schmalz.

Building an Application
Ergonomic issues of workers lifting and reaching comprise incentives for manufacturers and distributors to consider investing in robotics for palletizing and de-palletizing applications. “Palletizing is a repetitive task, an ergonomic concern. Throughput with a robot is much higher than with a person using a lift assist,” says Maitre.

In a similar vein, Motoman’s Tom Sipple says, “Handling cases over a day means handling a lot of weight. Distributors have great difficulty to get and retain people to work in these conditions. Turnover rates are very high as are the costs of training and retraining workers. Just one back injury can cost as much as one robotic palletizing system.”

Palletizing and de-palletizing applications are a continuing bright spot for the robotics industry. “Palletizing and de-palletizing applications are definitely a growth area. In 2009, the whole robotics industry declined by 50 percent. Despite that decline, palletizing and de-palletizing applications grew by 3.5 percent,” recollects Adept’s Sridhar Karnam. “This application grows by as much as seven percent a year and we see five to seven percent growth in palletizing and de-palletizing applications in the next five years.”