Used stackable plastic pallets

Why the bottom pallet matters

In a stack, the bottom pallet carries every load above it, at rest. That is the static load, the highest of the three ratings. One supplier lists 48 x 40 stackable pallets with dynamic ratings of 2,500 to 5,000 lb and static ratings of 3,000 to 30,000 lb. A static rating of 3,000 lb and one of 30,000 lb are different tools.

Checking a used stackable

Slow bending

Plastic pallets creep, which is slow bending under a heavy load held for a long time. Freezing can make some materials brittle. A used stackable that sat at the bottom of a tall stack for months may have a visible bow. Look for it before you reuse that pallet as a bottom pallet.

• Look for a bow along the long axis
• Look for splayed feet
• Look for stress whitening at corners

Stacking is a rating, not a shape

A pallet that looks stackable may not be rated to carry another loaded pallet on top of it. The static rating is the weight a pallet holds at rest on a flat floor, and it is the number that governs a stack. Read it from the plate on the bottom pallet of a stack, and ask what happens to the rating when the pallet is warm, wet or old. If the deck has bowed, the stack will lean, whatever the plate says.

Ask the seller whether the lot was stacked in service or only moved on a single level, since a pallet that has been stacked under load for months carries a different history from one that has not.

Signs a stack is going wrong

Watch the bottom tier. Bowed deckboards, runners that splay outward, a corner that has started to creep downward and a lean toward one side all say the load is working the plastic harder than its design allows. Plastic creeps, which means it slowly deforms under a steady load even when no single moment looks dangerous. A stack that stood straight on Monday can lean by Friday, so check stacks at the start of a shift, and break them down if the bottom tier is losing its shape.

Interlocking and non-interlocking tops

Some stackable pallets have a rim or lip that locates the pallet above; others are flat and rely on the load itself. A locating rim keeps stacks square but can crack when struck. Check the rim all the way round, because a broken section lets the next pallet slide and puts the stack at risk.

Questions to put to any seller

• Where did these pallets work, and what did they carry?
• How were they sorted, and who walked the lot?
• Are any welded, riveted or fitted with replacement parts?
• Can the maker's plate be photographed on several pallets?
• Will the description be sent in writing before payment is discussed?

Planning around the seasons

• Cold months bring brittle resin, so handle gently and avoid sharp drops.
• Warm months soften decks, so shorten stacks and keep loads in shade.
• Harvest, holiday and promotion peaks use pallets faster, so order earlier.
• Wet seasons add weight in the ribs, so allow a drying day before indoor use.
• Plan returns and exports for the weeks when dock space is free.

Words used on this page

Welding repair

Plastic is hard to glue, so cracked parts are normally welded.

Creep

Slow bending of plastic under a heavy load held for a long time.

Stackable

Loaded pallets can sit on top of each other, up to the static rating.

Fork pocket

Opening in the pallet where the forks go.

Dynamic load

Weight a pallet carries while moving on a forklift, pallet jack or conveyor.

What the sources say

• Static capacity is the highest of the three ratings; racking is often the lowest; dynamic is always lower than static. nelsoncompany.com
• Freezing can make some pallet materials brittle and reduce performance. nelsoncompany.com
• Plastic pallets can deform (creep) under heavy long-term loads and are hard to repair. en.wikipedia.org
• PHS lists 48 x 40 stackable plastic pallets with dynamic ratings of 2,500 to 5,000 lb and static ratings of 3,000 to 30,000 lb. phsinc.com

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