In the pallet world, wood has always been king, traditionally claiming about a 95-percent share of the overall market. And for good reason; there's a lot about the material to love. "It is cheap, strong, and safe," says Laszlo Horvath, director for the Center for Packaging and Unit Load Design at Virginia Tech.
But wood does have its disadvantages. For starters, there's the risk of splinters and protruding nails. And because wood pallets can harbor insects, pathogens, and mold, there's the issue of sanitation. Drawbacks like these have driven interest in "alternative" pallets made from materials such as plastic, paper, and metal. "For pretty much every disadvantage that wood has, there is a pallet out there that helps users [avoid] that problem," says Horvath.
So what's the best type of pallet to use? As is often the case, there's no one-size-fits-all answer—the choice will vary with the application. What follows is a look at the strengths and weaknesses of each type of material and the applications to which it is best suited.PLASTIC: CLEAN BUT COSTLY
Next to wood, plastic is the most common material used for making pallets. Studies show that plastic accounts for 11 percent of the market demand, with 37 percent of pallet users employing at least some plastic units, according to Horvath. And interest in plastic is on the rise: In a 2013 report, the market research firm The Freedonia Group projected that demand for plastic pallets would grow at a double-digit pace through 2017.
Plastic pallets offer many advantages: They're impervious to pests and mold, they're free of splinters and nails, and they're easy to clean. Plus, they're lightweight. While wood pallets range in weight from 30 to 70 pounds, Horvath says, a plastic pallet can weigh as little as 10.
For these and other reasons, plastic pallets appeal to users across a broad range of industries, according to Curt Most of Orbis Corp., which manufactures plastic pallets. For example, food and pharmaceutical companies value them for their hygienic qualities, while many retailers prefer them for aesthetic reasons, particularly if they use pallets for store-floor displays. Companies that deal in high-end electronic goods often choose plastic because the pallets don't have any nails or protruding edges that can damage a product or its packaging, according to Most.
Plastic also has its downsides. Primary among them is cost. Plastic is typically more expensive than wood, especially if a company needs customized pallets (something other than the standard 48- by 40-inch footprint) that require unique molding and tooling, says Doug Gaier, director of regional sales for the pallet company Millwood. That makes them less than ideal for one-way shipments or applications where the pallet might get lost. In recent years, plastic pallet companies have responded to this concern by adding tracking devices and developing systems to help users keep tabs on their pallets. But the cost and the risk of "leakage" remain a deterrent for many companies.
Furthermore, although plastic is durable, it is not very "stiff," meaning the components of a plastic pallet will bend more than their wood counterparts will, says Horvath. This bending is sometimes known as "creep." And it's a bigger problem than it might seem, according to Horvath. "A lot of people say, 'Why do you care about the bending of the components if the pallet doesn't break?'" he says. The issue, he explains, is that if the components bend too much, it can result in the uneven distribution of stress on the top of the pallet. That, in turn, can compromise the integrity of the product—for example, causing bottles to leak or unit loads to become unstable.
A newer type of plastic pallet made from thermoset resins, as opposed to thermoplastic resins, may offer an answer to this problem. According to Fit Pallets, a maker of thermoset composite pallets, thermoset resins undergo a chemical change when they're molded, which strengthens the material and makes it less likely to bend or creep.
On top of that, thermoset pallets pose less of a fire risk than conventional thermoplastic pallets. Traditional thermoplastic pallets burn hotter and faster than wood ones and as a result, require a higher-capacity sprinkler system or a fire retardant. Thermoset plastic pallets, however, meet the UL 2335 classification for flammability (meaning they perform as well as or better than wood, and therefore don't require the costlier sprinklers) without the addition of fire retardants.PAPER: LIGHT BUT SHORT-LIVED
In recent years, another type of pallet—the corrugated paper pallet—has started making inroads in the market, according to Horvath. The Swedish furniture retailer Ikea, for example, made a big splash in 2011 when it announced it was switching from wood pallets to paper. The Freedonia Group estimates that corrugated pallets represent 11 percent of all market demand.
The main selling point of corrugated pallets is their low weight (roughly 8 to 12 pounds), which makes them easy to handle and reduces shipping costs. Ikea's pallets, for example, are 90 percent lighter than their wooden predecessors. This makes them a good choice for airfreight shipments and containerized loads, says Horvath.
The pallets are also 100 percent recyclable and, unlike wood, do not require any sort of heat treatment to prevent pest infestation. As a result, they're well suited to export use.
Corrugated pallets, however, have a short lifespan, which means users shouldn't look to get multiple trips from them. They also cannot handle heavy loads. Nor do they stand up to moisture.METAL: HEAVY GOING
Metal pallets are typically made from steel, aluminum, or some combination of the two. The market for metal pallets is still relatively small. According to Horvath, the material only represents 0.8 percent of the market demand and is being utilized by 7 percent of users. The Freedonia Group, however, expects that demand for metal pallets will grow at a faster rate than demand for pallets of any other material into 2017.
Both steel and aluminum pallets are strong, durable, and extremely easy to clean. Steel pallets, however, tend to be extremely heavy, often weighing over 50 pounds, according to Gaier. As a result, their use is largely restricted to specialized heavy-duty applications, says Horvath. For instance, the military uses steel pallets for shipping machinery and munitions.
Aluminum is lighter than steel, weighing on average less than 40 pounds for a standard 40- by 48-inch pallet, and offers a high strength-to-weight ratio, according to Peter Johnson, president of Eco Pact, a manufacturer of aluminum pallets. "Aluminum is also clean and sterile, and doesn't rust," he says. "Additionally, bacteria won't grow on it."
These qualities make the pallets well suited for industries such as pharmaceuticals, food, and industrial machinery, Johnson says.
Aluminum pallets can either be welded together or riveted, according to Johnson. Welded pallets are generally stronger but cannot be easily repaired. Eco Pact, however, makes riveted pallets with an interlocking design that improves the strength, according to the manufacturer.
While aluminum still commands only a small share of the market, Johnson says it's made headway over the last two years because of the material's cleanliness, safety (lack of nails, splinters, and protruding boards), and long lifespan. He expects demand for aluminum pallets to grow by 10 to 15 percent over the next five years.A BIGGER PIECE OF THE PIE?
It seems unlikely that plastic, paper, or metal could topple wood from its perch at the top of the pallet market—a seat it has held for more than 70 years. "Even when you combine all of these other alternative pallet materials, you're still only talking about less than 5 percent of the pallet market," says Millwood's Gaier. "Wood is still the most sustainable, best dollar-value material for a pallet."
Yet by any measure, the pallet market is huge and growing. The Freedonia Group expects North American sales to hit 1.3 billion units by 2017, with a total value of $16.9 billion. And a bigger market means more room for lots of different types of pallets. As makers of alternative pallets proliferate and innovate, it seems likely they'll be able to carve out a profitable niche for themselves. And companies that have not looked at their pallet choices recently may find it advantageous to re-examine their options.