Palletizing (or skidding) freight not only assists in the consolidation of packages, but also greatly reduces the chance of damage or loss by reducing the handling of the individual boxes. The recommended rule for stacking of boxes (or cartons) on a pallet is the column stack. This will increase the top to bottom compression strength of all boxes on the pallet. Misalignment of boxes will reduce the boxes’ compression strength, so alignment is important.
The exception to this rule is if the product inside the boxes is rigid (such as pails of paint), then interlocking the boxes will increase stability. These would be stacked corner-to corner and edge-to-edge. Overhang of boxes from the side of the pallet is not only inadvisable, but will exponentially increase the chance for damage of boxes and products.
Pyramid stacked loads are not recommended, as the top boxes are exposed to damage from other shipments. Level surfaces provide maximum strength and stability and give the best chance that the shipment will remain intact. Pyramid shaped loads may cost more to ship (dim weight rules) and also may be subject to being broken down and/or delayed in transit.
Wooden pallets are the most common (and cheaper) option for palletizing freight. Forklifts and pallet jacks are used to move pallets while in transit, so the quality of the pallet can greatly impact the security of the freight. Pallets should always be in good condition and of the proper size to accommodate the freight without overhang. Four-way entry of all pallets is advised.
Plastic pallets are an option and, though more costly, they are reusable for a longer period of time. Due to their design of a solid bottom deck, the freight is better protected from forklift damage. The plastic surface, however, is also slippery, which makes handling and placement more difficult. Another consideration is that plastic pallets are heavier than wood.
Corrugated pallets are another alternative – they weigh less, are easily recycled, and are not subject to the international restrictions on non-manufactured wood products. However, these pallets have not shown to stand up to the normal rigors of transportation, so they are not recommended.
- Crating is the best protection for the safe transit of sensitive or fragile products, if constructed correctly, using quality lumber
- We recommend using quality plywood for crate construction – not OSB (oriented strand board) or MDF (medium density fiberboard)
- All wood should be ISPM 15 compliant when shipping internationally
- Knots in the lumber should not be too large, nor should they be in a critical location (where fasteners are anchored)
- Diagonal braces should be used on each panel to increase the strength and integrity of the crate
- All fasteners (nails, etc) should be driven into the side-grain of the wood, never the end-grain, to increase the holding power
- Crates should always be constructed using Interlocking corners
Many countries have restrictions on wood products – heat treatment and/or chemical treatment – to avoid possible insect infestation. Most of these countries have adopted the ISPM 15 Rules as their guideline for restrictions on imports. Keep this in mind when constructing crates for shipments with an ultimate destination outside the USA.