Showing Off at Pack Expo: Mixed Pallet Loads

The need for more efficient order picking and stocking are spurring interest in automating the assembly of mixed pallet loads. These technologies will be demonstrated at PACK EXPO International, October 31-November 3, 2010, at Chicago's McCormick Place.

Automating mixed-load building addresses retailer demands for rainbow point-of-purchase display pallets and the desire to inventory smaller quantities of single SKUs. It also minimizes errors and reduces labor requirements in the warehouse. On the retail floor it enhances consistency and optimizes pallets to increase shipping, delivery and/or stocking efficiency.

“Grocery stores and convenience stores don't want to stock full pallets of the same SKU,” says Stephen Moseley, industry team leader for warehouse and distribution at Intralox, a supplier of material handling equipment capable of automating mixed pallet building. “C-stores, especially, are too space-constrained to handle dedicated pallets of product,” he explains.

The manufacturing side of the supply chain also finds mixed pallet loads appealing. “A lot of consumer packaged goods companies view warehouse automation as the largest opportunity [today] for efficiency and cost savings,” says Scott Smith, global director market development and emerging businesses at Hartness International, a supplier of palletizing and mixed case picking technology through its HartnessVertique (pronounced ver Tee Q) subsidiary.

“Order picking has always been one of the most labor-intensive functions in the distribution center environment,” explains Dan Labell, president of Westfalia Technologies, a supplier of warehouse management software, automated storage and retrieval systems and robotic palletizers. It's also been one of the most difficult operations to automate due to the multitude of package weights, shapes and materials typically involved. However, he reports, there are robotic solutions available to handle the different package types and software to provide the intelligence needed to sequence the right product at the right time to build a dense, stable mixed load.

Several companies, including Intelligrated Inc. and FANUC Robotics America Inc., offer end-of-arm tools that enable the robot to handle thousands of SKUs.

Payback can be significant. “It's not uncommon to reduce pick labor 60% to 70%,” reports Labell.

Mixed loads often take the form of pallets where each layer consists of a different flavor. “Full layers of the same product make a nice loading platform for the next layer,” explains Brad Leonard, vice president, packaging innovation and sustainability at CAPE Systems Inc., which will introduce pallet pattern and packaging design software at Pack Expo.

Increasingly, however, product is mixed within layers, adding to the complexity and presenting a challenge Leonard equates to assembling a three-dimensional jigsaw puzzle.

“The more packaging types, the more challenging it is,” agrees Labell.

Mixed loads also increase the number of “touches” a product experiences. Now instead of shipping homogenous pallets built at the end of the packaging line, product may be palletized in a homogenous load, depalletized and repalletized in a mixed load, increasing chances of damage, particularly with the source-reduced packaging being adopted to meet sustainability initiatives. “When combined with lightweighting, these additional touches present some real challenges,” says Smith.

Mixed Load Systems

Mixed pallet loads are generally built in the warehouse. “There aren't many applications where you have different packaging lines feeding the same palletizing space,” explains Leonard of CAPE.

Mixed load systems consist of software for decision making and hardware for arranging product to build a dense, stable pallet load. Hardware frequently involves robots with highly flexible end-of-arm tooling that gently handle a wide range of package types, sizes, shapes and weights.

Basic systems may stage incoming product for use in a mixed load. More sophisticated systems depend on product being picked in the proper sequence so it arrives in the order the pallet requires. The most advanced systems possess the intelligence to work on the fly to create the best possible arrangement of randomly arriving product.

An integrated system from Intralox, based on its activated roller belt technology, handles corrugated cases and other packages rapidly and gently. Capable of depalletizing up to six layers per minute, the system can handle complex interlocking layer patterns with up to 80 cases per layer. In this scenario, an Intralox pallet layer descrambler singulates and orients product from single-SKU layers so a right-angle sorter (DARB) can transfer them into a buffer or storage system. Single SKU storage accumulation lanes with up to six lanes per drive hold product until it's needed.

When an order is received, the system releases the buffered cases in the proper sequence through a perpendicular merge so the Intralox pallet layer former can stack the mixed load pallet. If needed for the stacking pattern or merchandising requirements, a touchless case turner can be installed after the perpendicular merge to rotate cases into the proper position for the pallet layer former.

A mixed-load palletizing system from Intelligrated for a Discount Auto Parts distribution center in Gallman, Miss., now part of Advance Auto Parts, consists of pallet carousels, a gantry robotic palletizer and order management software. Under direction of the software, the carousels rotate pallets to the proper location, the gantry robot picks a layer of product and transfers it to the appropriate pallet to create a rainbow load. As positions are emptied, the software alerts the operator to replenish the carousel.

Since mixed load palletizing typically begins with case picking, Hartness plans to demonstrate two case picking technologies in a loop in its booth at PACK EXPO. The demo line consists of a robotic HartnessVertique hybrid palletizer, a robotic case picker and 16 patented storage towers, which deliver cases on demand to the loading area. Proprietary VPS software interfaces with order systems and configures the pallet according to rules related to product size, weight and delivery sequence. The hybrid palletizer relies on robotic layer forming to gently position each case in the proper orientation and reaches speeds of up to 90 cases per minute. By eliminating traditional slat dividers and bump turns, robots handle virtually any pallet pattern with no mechanical changeover.

FANUC Robotics will introduce a mixed case palletizing suite capable of building mixed pallets three ways. In the first, algorithms tell the robot in real-time the best stacking pattern for randomly arriving product. In the second, a preplanning mode interfaces with up- and downstream systems to analyze the order, optimize the load and provide picking instructions so items are delivered to the robot in the proper sequence. The third option combines the preplanning data interface capabilities with an algorithm that tests the pallet load design to confirm the robot can build it. It's also possible to switch between preplanned and real-time modes on the fly. For example, says Don Faulkner, director, Automated Systems Group at FANUC, “If we are running the preplanned scenario and a particular case is missing or out of sequence, we can switch immediately to the real-time mode to load the product in the best possible position and then revert to the preplanned sequence for the next pallet,” he explains.

Westfalia combines a modular software suite with high-density storage, pallet conveyors, picking and robotics. Its Savanna.NET warehouse management system (WMS) works at the management level to control robots, generally from KUKA Robotics Corp., as well as product movement and tracking. Equipped with standard interfaces, the software integrates with virtually any programmable logic controller as well as enterprise resource planning systems. For firms with an existing WMS, the basic warehouse control system module can control automated processes such as conveying, storage and retrieval and link to the host system.

Software provider CAPE Systems plans to unveil CAPE Pack, version 2.11 at PACK EXPO. An updated module automatically calculates mixed pallet load solutions using algorithms and loading restrictions for each pack. Mixed loads also can be designed manually using a drag-and-drop function in the editor tool.

TOPS Engineering Corp. will demonstrate software for three mixed pallet variations: display pallets; pick, sort and palletize; and sequenced order picking. The latter can be manual or automated. In an automated system, the software coordinates the action of a robot and an automated storage and retrieval system to arrange product on the pallet in reverse order of how it will be removed by the route driver or store personnel. For direct store delivery, arranging orders by stop minimizes handling for the driver and reduces the chance of error, while expediting the stocking process for store personnel. The hardware- and software-agnostic software works with any robot or upstream software programs for warehouse management, order entry or enterprise resource planning.

Beginning to Build Mixed Pallets

Suppliers of hardware and software that enables assembly of mixed pallet loads agree accuracy, flexibility and scalability are essential attributes for any mixed load system.

“The first step is to define needs,” says Bill Natsch, director of robotics integration at Intelligrated Inc., a supplier of robotic depalletizing and palletizing systems for mixed-load applications. Will layers be homogeneous or mixed? What rate is needed? Will end-of-aisle or rack displays be involved? How are products delivered to the pallet building point? What software is in use, and how does it interface with other systems? How much surge capacity is needed to address periods of high demand? Each answer “plays a role in determining the best equipment [and software] for the application,” he explains.

“It also may be necessary to overhaul the replenishment system,” says Martin Clark, director of business development and marketing at Intelligrated. Otherwise, replenishment can be a bottleneck, especially if the warehouse is some distance away and its systems are performing other tasks. In addition, good visibility regarding upcoming orders is essential. “If you know a certain pallet configuration needs to be built at a certain time, you can be prepared,” explains Clark. “Working in real-time is more challenging,” he notes.

Scott Shannon, packaging team leader, North & Latin America at Intralox, advises, “Think toward the future. Packaging is evolving very quickly. Don't just think in terms of current package types and rate requirements.” Without this kind of forethought, “a system based on today's packages could be almost obsolete within18 months,” he warns.

A scalable solution also accommodates higher levels of automation as needs change, allowing end users to build a fully automated system that would not be affordable initially.

Along with scalability, the system needs to accept new products with minimal effort. “We don't see any slowing in SKU proliferation, so the product mix you have today will probably look very different in two years,” explains Smith of Hartness.

Dick Motley, manager, National Distribution Group at FANUC, recommends selecting a supplier with demonstrated expertise and asking them to demonstrate how its solution would handle the application. “Ask to see a graphical representation of how orders would be processed,” he advises. It's important to know what pallets will look like, how dense they'll be and how many will be needed.

“Simulation may uncover certain bottlenecks or negative design elements that need to be solved before actually building the equipment,” explains Westfalia's Labell.

Bill Rehring, founder and president of TOPS Engineering, agrees and recommends going one step further in the supplier vetting process. “Build a sample and test it to make sure it works,” he advises.

“Up-front planning is essential to establish a clear understanding and clear expectations of what the automation is going to do,” concludes Motley.

Hallie Forcinio is a business writer based in Cleveland, Ohio.