Hybrid Palletizing solution Hits the sweet spot for Hershey

July 1, 2008
At the Hershey manufacturing facility where packaging systems engineer Alex Diaz works, there is only one constant: constant change. The plant manufactures

At the Hershey manufacturing facility where packaging systems engineer Alex Diaz works, there is only one constant: constant change. The plant manufactures Hershey products for an assortment of brands including Hershey®’s, Kit Kat® and Cadbury®, with a wide variety of low- to mid-velocity SKUs that can change seasonally, weekly, and even daily based on demand from the Hershey marketing team, retail stores, and consumers.

For a company demanding this much flexibility, its packaging, logistics, and material handling solu­tions must be up to the task. This was the chal­lenge when the Hershey engineering group looked to material handling integrator FKI Logistex to successfully revamp and automate the palletizing operations at the Hershey facility.

Until 2005, everything at the Hershey plant was hand-palletized, resulting in low palletizing rates and high manual labor costs. “We had three to four people palletizing per line, per shift, for three shifts a day,” says Diaz. “So we’re talking about 12 to 15 people palletizing at once, depending on how complicated the patterns were.” Employees were also doing a lot of heavy lifting — some boxes in excess of 50 pounds — leading to ergonomic issues and safety concerns.

When Hershey’s increasingly wide variety of prod­uct SKUs and packaging configurations started to require faster and more flexible palletizing, Diaz and fellow Hershey engineers knew it was time to make the switch to an automated system. Automated pal­letizing promised increased capacity, decreased labor costs, a safer work environment, and the versatility Hershey required for its diverse product line.

fitting Big flexibility into a small space
Diaz, along with project manager Dennis Empson and staff engineer Matt Eroh, teamed up with long-time material handling partner FKI Logistex to design an automated palletizing system that could handle Hershey’s low- to mid-velocity SKUs — ranging from one to 40 cases per minute. Keeping in mind that the entire system would need to fit within the tight space constraints of the plant’s approximately 7000­square-foot palletizing area, the team weighed their two best options: con­ventional and robotic palletizing.

Almost immediately, it became clear that conventional palletizing, while fast and cost-effective, would not work with Hershey’s space restric­tions. “To implement a multi-line system with conventional palletiz­ers, you need enough accumulation conveyor to accommodate up to two full pallet loads on each line, depend­ing on load lengths and production rates,” explains Mark Conreux, the senior project manager from FKI Logistex. “Hershey’s eight produc­tion lines required significantly more conveyor than they had space to accommodate.”

Robotic palletizing, on the other hand, offered a more versatile op­tion by enabling Hershey to send three different lines to one robot and palletize in three different posi­tions at once. This greatly reduced the amount of conveyor required, but posed a problem of its own: The robots could not keep up with the production rates of Hershey’s higher-velocity SKUs.

Hershey and FKI Logistex quickly realized that a combination of robotic and conventional palletizing was the best solution to meet Hershey’s requirements, given the limited floor space available. The team worked together to design a system that sends mid- to high-velocity SKUs to an FKI Logistex A-780 case pallet­izer, and low-velocity SKUs to one of three Motoman EPL 160 jointed-arm robots.

A partnership between FKI Logistex and Motoman Inc. facilitat­ed Hershey’s transition to robotic pal­letizing, a technology not previously introduced in this facility. “Most companies focus their expertise on either conventional or robotic pallet­izing,” says Diaz. “But the experience FKI Logistex has with both technolo­gies made the integration very easy and was the main reason that we chose to use a combination of both to meet our palletizing requirements.”

According to Conreux, who has personally overseen the installation of many conventional palletizers and ro-bots, putting them together just made sense. “We gave Hershey the best of both worlds and developed a unique palletizing solution for its product line,” he says.

A fully integrated solution
The new system includes a wide range of FKI Logistex technologies, including the A-780 case palletizer; photo-eye Accuglide™ accumulation conveyor, gravity roller conveyors; chain-driven live roller (CDLR) con­veyors and motor-operated turntables; a high-speed, laser-positioned transfer car; and high-speed V-Belt live roller (VBLR) conveyors. The stand-alone PLC control system features fully cus­tomized code work by FKI Logistex.

Diaz and his team were especially impressed with the FKI Logistex photo-eye Accuglide powered roller conveyor, which provides zero-pres­sure accumulation of cartons. “The Accuglide conveyors are excellent,” says Diaz. “And the fact that FKI Logistex was able to integrate all their conveyors with the rest of their equip­ment made it much easier for us to get the complete package.”

Conreux adds that FKI Logistex of­fered Hershey the breadth of product line to choose the equipment that best suited their requirements for the low­est cost. “A lot of integrators make the same claim, but they do not manu­facture all of the equipment. Many times they force their limited product line into an application instead of applying the best available solution. At FKI Logistex we manufacture a wide range of products, giving us the flexibility to provide exactly what the customer requires.”

Conreux notes that one of the biggest challenges of the project was finding an end-of-arm tool for the ro­bots that could handle Hershey’s wide variety of SKU sizes and weights. Although FKI Logistex typically designs and manufactures the tooling for the robots they integrate, Conreux and his team decided to outsource the end-of-arm tool based on the product specifications for this project. They chose to use a UniGripper® flexible vacuum tool from Tepro Machine & Pac System, which activates specific vacuum areas to create the necessary lifting forces for each package, based on the shape and location of cases programmed into the system. “I’ve installed some other robots, and this was by far the easiest-to-use and most versatile end-of-arm tool I have ever worked with,” says Empson.

Palletizing system features Built-in flexibility for future change
The new palletizing system gives Hershey the capability to easily inte­grate the remaining hand-palletized lines into the automated system by adding a spur conveyor and possibly a fourth robot based on future demand. This built-in flexibility is something that Diaz agrees should be standard on all material handling systems.

“Most of the SKUs that we started the project with were not being pro­duced by the time we got the system running,” says Diaz. Three new pat­terns were added to the A-780 palletizer before FKI Logistex even arrived on-site, and up to 50 percent of product sizes and patterns were changed before installation was complete. Because of these packaging changes, Hershey commissioned FKI Logistex to install pattern genera­tion software for the A-780, which Hershey had chosen not to include in the original system design.

“At first, when our packaging department came to us with a new pattern we had to e-mail it to FKI Logistex to make changes to the PLC code,” explains Diaz. “This process required an engineer to analyze the new pattern requirements, ensure that existing patterns would not be ad­versely affected, program the changes, and then upload the code back to us. With the FKI Logistex pattern gen­eration software, the Hershey plant operator can directly program the new pattern into the palletizer, test it, and have it operational in a matter of hours.”

The FKI Logistex pattern genera­tion software is controlled by an easy-to-use touch screen display directly connected to the A-780. After enter­ing a password-protected “utility” mode, Hershey plant operators can add new patterns and make changes in real time.

“The pattern generation software is a recommendation I would give anyone for this type of system,” con­tinues Diaz. “It gives us the flexibility to make changes ourselves and get the new packaging configurations up and running quickly. With six new SKUs it pays for itself.”

FKI logistex offers training for Hershey Plant operators
As part of the contract, FKI Logistex provided on-site training on the new system to Hershey personnel. Select Hershey mechanics also visited Motoman for additional training on the robotic palletizers. More than 30 Hershey employees received training, including all of the plant’s forklift operators and electrical technicians.

“Once we reached the point where the operators were comfortable with the system, we’ve been running ef­ficiently,” says Diaz.

“And the fact that Hershey has yet to call FKI Logistex to make adjust­ments to the system is a testament to just how well the training worked,” adds Empson.

From the kitchen to the consumer
In the main hallway of the Hershey manufacturing facility, an overhead system of FKI Logistex conveyors and merges bring cartons of finished Hershey products to the palletizing room from various production opera­tions around the plant.

SKUs with high production rates enter on the high-speed line, which leads directly to the FKI Logistex A-780 case palletizer. A bar code scanner identifies each SKU and its associated pattern, letting the A-780 immediately palletize up to 7 cartons per minute. Positively driven, heavy-duty FKI Logistex chain-driven live roller (CDLR) conveyors and a motor-operated turntable direct each complete load to a stretchwrap­per capable of handling up to 60 loads per hour.

Lower-velocity SKUs enter the pal­letizing room via three lines of case conveyor. Cartons are scanned and sorted at up to 2 cartons per minute by FKI Logistex Sortrac air-oper­ated right-angle pushers into seven lines feeding three Motoman EPL 160 jointed-arm robots, or bypass the robots to an optional hand-pal­letizing lane. The robotic portion of the system uses an FKI Logistex laser-positioned rail-running transfer car to transfer the palletized loads to the turntable with high speed and accuracy. The turntable then directs the palletized loads to the stretch-wrapper.

The entire system feeds a single drop-off point, where fork trucks take the loads to the storage area until they are shipped to a distribution center (DC) for direct retail to mass markets.

All the products in the automated palletizing process are palletized on cardboard slip sheets instead of tradi­tional wooden pallets. “By removing a pallet dispenser we saved two things: space and money,” Diaz explains. “We do not ship on pallets, so the forklift operators only need to drive one type of forklift now instead of two.”

Hershey engineers Beat the clock
Hershey and FKI Logistex faced an aggressive timeline for installa­tion of the new palletizing system. Once the installation process began, the Hershey team tore out conveyors, vacuum lifts, and other hand-pallet­izing equipment and employed hand palletizing in other areas throughout the plant.

Crews worked multiple shifts and overtime in a very tight space, but their hard work paid off. “We installed the entire system in five weeks and had it commissioned in three and a half weeks,” says Diaz. Working long hours, Hershey engi­neers checked the wiring of the entire system in less than three days, an impressive feat.

FKI Logistex provided Hershey with technical support during instal­lation and commissioning to help the team get the project completed. “We had an FKI Logistex Customer Service Engineer (CSE) come out who was excellent on both the con­ventional palletizer and the robot,” says Diaz. “He got up to speed very quickly and worked with us to move the project to completion.”

safe, Reliable, and easy-to­maintain solution Provides a Real Roi
Since the completion of the project in June 2006, Hershey has seen increases in palletizing speed and efficiency, and has had no major problems with the equipment or the system itself to report. The equip­ment, which has proven to be reliable, is saving Hershey a great deal of money on manual labor costs, as well as greater potential savings from reducing ergonomic complaints.

Hershey engineers are happy with the system’s performance, and Empson has called the palletizing solution the “latest and greatest” in Hershey material handling systems. Conreux agrees that this has been a very successful project for everyone involved. “We would certainly do this type of project for Hershey again,” he says. “FKI Logistex has had a great relationship with Hershey for many years and we look forward to continu­ing to provide them with the best material handling solutions on the market.”

Throughout the course of his first major material handling project, Diaz says he learned a lot about adapting to new technologies and being prepared for future change.

“Basically, nearly everything you plan has changed by the time you implement it,” notes Diaz, referring to the constant packaging changes he faced during the project. “Change comes quickly,” he continues, “and you have to adapt to it as quickly as possible to be successful.”