A pallet is a flat structure used to transport goods in a stable manner. This is done by a variety of machines, including:
- Front loaders
- Jacking devices
Pallets are similar to skids, except they have boards on their bottom deck. Goods are typically secured to a pallet in some manner, including straps, shrink wrap and stretch wrap.
Pallets were invented in the early twentieth century and have largely replaced older forms of crating such as barrels and boxes. One of the most significant advantages of pallets over these other forms is their ability to be used with modern packaging containers such as the intermodal containers and corrugated boxes used in bulk shipping.
Pallets are commonly made of wood, although they can also be made of other materials such as metal, paper, and plastic. The best type of wood for making a pallet depends on factors such as its design and cargo.
How Design Impacts What Kind of Wood Pallets Are Made From
A pallet’s design reflects its purpose, which includes:
- General use
Additional parameters in a pallet design include the type of fasteners used, which are usually nails or staples.
Stringer & Two-Way Pallets
Pallets may be classified as stringer or block pallets, depending on the number of liftable sides. The simplest and most inexpensive design is a stringer, or two-way, pallet, which is liftable from only two sides.
Stringer pallets are generally considered disposable items and are usually thrown away after being used once. These pallets are rarely resold.
Block & Four-Way Pallets
A block, or four-way, pallet is liftable from all four sides, requiring a slightly more complex design but offering greater strength. Block pallets may be color-coded to indicate their load capacity and other parameters.
They’re considered a reusable item, so block pallets typically require a deposit to the supplier and are often resold.
How Contamination Affects What Kind of Wood Pallets Are Made From
Wood is an organic material, so it poses a risk of biological and chemical contamination that isn’t found in other materials such as metal or plastic. Wood can carry bacteria and insects, which is a critical consideration when the pallet carries food and pharmaceutical products.
The International Standards for Phytosanitary Measures No. 15 (ISPM 15) is a measure developed by the International Plant Protection Convention (IPPC) that specifically addresses the use of wood to transport consumable products. The Food and Drug Administration (FDA) also provides specifications on pallets used to transport materials regulated by that agency.
Softwood is preferable for these applications because they can be dried in a kiln before use to reduce the moisture content, resulting in cleaner lumber. This property allows softwood to be used in the transportation of pharmaceuticals and food.
Various Kinds of Wood Pallets Are Made From
The manufacturers of wood pallets generally classify their pallets as being made of hardwood or softwood, rather than wood from a particular species of tree.
Softwoods grow faster and are therefore less expensive than hardwood. Stringer pallets are usually made of softwood since they’re frequently discarded after the trip. Block pallets are more likely to be made of hardwoods due to the greater strength they require.
The most common kind of wood pallets are made from in the United States is softwood, more specifically southern yellow pine (SYP), according to a USDA study. This study shows that SYP accounts for 18.9 percent of all wood used in the US. This study also shows that oak is the most popular hardwood, collectively accounting for 17.1 percent of lumber usage.
SYP is one of the most inexpensive types of lumber throughout the United States, making it a popular choice for softwood pallets. It’s also much lighter than oak, which can be a critical factor in shipping. SYP’s biggest disadvantage for the use of pallets is its softness, which is why it’s structurally weak.
Additional types of softwood available in the United States include other species of pine, Douglas fir, and spruce.
About 600 species of oak exist throughout the world, although only a few species are suitable for commercial lumber.
Oak lumber in the United States is generally classified as white oak or red oak, both of which include more than ten species. Oak is a high-density hardwood that’s readily available in large quantities. This density makes the wood very hard and strong, although it also makes it much heavier than softwoods.
Other types of hardwood used to make pallets in the United States include maple.
Pallets are more difficult to construct from hardwoods like oak, but it’s also the preferred choice of material for block pallets that will carry heavy loads.
The lumber used to make hardwood pallets is typically left over from making furniture because its quality wasn’t high enough. Its high strength allows the boards in hardwood pallets to be thinner than those used in softwood pallets, making them less bulky.
One disadvantage of hardwood is that the grains begin to separate from the rest of the wood as it ages, resulting in a slightly fuzzy appearance. However, this property shouldn’t be an issue for pallets.
Other Types of Wood Pallets Are Made From
The kind of wood pallets are made from varies greatly by country since pallets are generally made of the most inexpensive wood locally available that will handle their expected load. This practice means that pallets are often made of woods that might be considered exotic in other countries.
For example, pallets made of mahogany are quite common in India, but this wood is unlikely to ever be used to make a pallet in North America.