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Column: Informed Conveyor Decisions Start with Pallets

June 1, 2005
"One of the challenges is that a pallet might be selected because it's the right platform for some other piece of material handling equipment, yet wrong for the conveyor on which it will travel."

Astory in Hytrol Conveyor's (Jonesboro, Ark.) newsletter this month caught my eye. Under the title of Pallet Handling Load Application ... Part 1 was advice for making the right conveyor decisions. It boiled down to asking two key questions: What does the conveying surface (bottom of pallet) look like? And, what is the load weight?

The newsletter points out that while pallets might look similar, they are not and that impacts the conveyor decision. With the changing variety of new pallets entering the flow each year I wondered how a material handling manager could ever reach a conveyor-purchase decision. I figured I should get to the bottom of this subject by contacting folks who make their livelihoods determining the right pallets for the job. What intrigues me is how palletpurchase decisions are made. Is it all about money, what the pallet costs, or how the pallet performs that's the driver?

Ralph Rupert is a packaging engineer who makes his living teaching and doing research at the Center for Unit Load Design, Virginia Tech, in Blacksburg, Va. Each spring the center offers a short course in unit load design. Rupert says the course is offered to anyone, with particular emphasis on folks who have packaging and pallet-use in their job functions, but are not always packaging engineers.

My first question, whether pallet users and equipment buyers ever discuss what might be the most appropriate conveyor, met with some hesitation.

"Well," says Rupert, "not often enough—if at all." Apparently, the final pallet selection, even after specification from the guys who will be using the platforms, remains, in many cases, a function of the bean counters.

Phil Smith of the Smith Companies, Pelham, Ala., says the part of the equation that's missing in pallet selection, is the fact that pallets are not used in the controlled environment specifications presume.

"You have guys tossing pallets off the loading dock, landing on edge, for example," says Smith. "The durability and reuse the pallet owner gets [or doesn't get] are never figured as part of the cost. The pallet buyer should factor in maintenance float and cost of repairs, which can be substantial in large systems."

Matching the right conveyor to the right pallet depends on the kinds of pallets coming into the building.

"One of the challenges," says Rupert, "is that a pallet might be selected because it's the right platform for some other piece of material handling equipment, yet wrong for the conveyor on which it will travel."

Opting for a stringer-type pallet because it's less expensive and can be handled easily by lift trucks is fine, until it has to move on a conveyor that requires a perimeter-based shipping platform.

"And what do you do when you receive a load on a nine-post, nestable pallet," asks Rupert. "Then you need a belt conveyor—or anticipate a lot of damage."

I asked if these were the kinds of things he and Mark White, the director there, taught in the unit load design course.

"These things and a lot more," says Rupert. "We spend a lot of time on the interactions of pallets and material handling equipment."

Out where the rubber meets the road, John Clarke, a former instructor at the Center for Unit Load Design, is putting into practice what he told students for many years. Clarke's employer, the Nelson Company ( Baltimore), provides transport packaging goods and services. "A lot of what I do," says Clarke, "is work with people on this subject of interfacing the pallet with racks and conveyors."

Clarke says the key to success is to look at the entire picture. It's not always a matter of investing more money in heavier pallets. "I'm working with a company now where we've recommended adding another arm to its cantilevered racks to get the added support it needs. It won't cost them all that much more money, and it will make a huge difference in the rack's ability to support more weight."

Clarke notes that in his years in the business he's yet to work with a conveyor manufacturer on the challenge of matching the conveying surface to the conveyor in selecting structural and drive capacity of the conveyor.

Why is that? "Usually," says Clarke, "a company says, 'here's the conveyor ...' and we have to work with what's there."

An important point that Clarke makes is that the pallet/conveyor selection process is a three-legged stool. The manufacturer of the conveyor or material handling equipment and the manufacturer (or provider) of the pallets, have to work in harmony with the end user, also known as the customer.

Smith agrees. "A key element in many material handling systems is the pallet, yet it's never a consideration when a warehouse is built. We [pallet makers] have to stay closely tied to people on the frontlines who are in at the beginning of any building project."

Clarke's of the opinion that education is critical to finding the solution to pallet and equipment design problems. "If a progressive equipment company learns more about pallets, it is better able to serve its customers and becomes more competitive."

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