Ask Steve
August 23, 2024
Question from Jim: How much does poor pallet quality affect load containment?
Hi Jim,
Thanks for sending in your question. This topic finds its way into almost every Load Containment Lab Test Report we do for customers. So, it is something everyone should consider when developing their load containment standards.
Thanks for sending in your question. This topic finds its way into almost every Load Containment Lab Test Report we do for customers. So, it is something everyone should consider when developing their load containment standards.
Let me use a metaphor to illustrate the pallet’s role with respect to load containment. Would you build a $2B 100-story skyscraper on a bed of quicksand, or would you build it on solid bedrock? Absolutely, it would be on the bedrock! You are diligent in the development and manufacturing of your product, why would you stack your finished goods on anything less than bedrock?
Traditionally, pallets have been constructed from repurposed lumber, and then used and reused until there is very little left of them. There are standards for certain common pallet types, however, not every pallet manufacturer abides by those standards. That means pallet quality can be a hit or a miss. As an example, there is a specific nail design that grips the wood more effectively than a common nail, however, a large percentage of pallet manufacturers do not use them. As pallets are used, boards break, nails become exposed, and the structural integrity is significantly diminished. When the pallet degrades, it is no longer able to support the load effectively.
To properly anchor the stretch film to the pallet, the end boards on the deck of the pallet should provide a “grip point” at each corner. If those boards are broken, or missing, the stretch film is only gripping the ends of the long “stringer” board. If the stretch film is properly unitizing the load and a significant side force is applied, such as a high impact force, the load will tilt (but the layers will not shift), placing more concentrated energy at the pallet corners. Without the grip point of the top deck boards, the stretch film can “slip” up and off the stringer. The stretch film will maintain a unitized load; however, it will no longer be attached to the pallet and thus it is more likely that it will shift on the pallet when normal transportation forces are applied during the rest of its journey. Exposed nails or splintered boards can also puncture the stretch film as it is wrapped, and unless you are using our Rapid Bander, the chances are the web will immediately break when punctured. This can greatly impact your plant’s output.
How your product is shipped will also determine the amount of pallet degradation that occurs between points A and B. For instance, when you ship full truck loads, properly loaded and secured, you will see the least degradation. However, shipping LTL is like pulling the pin on a hand grenade, when the product is unloaded at its destination, it can look like an explosion happened. We found that products shipped LTL only a few hundred miles from Arizona to California were cross docked eight times! That is 16 times that it was loaded on a trailer or removed from a trailer. I will let you in on a little secret I learned; the forklift operators who work in the terminals are not incentivized by how carefully they move pallets, just how fast they do it. Rail shipping provides another set of challenges altogether, and as you can imagine, one solution does not cover them all. A successful Load Containment Standard needs to be developed based on due consideration of all the variables.
As you know, we study the physics of load failures, not just to isolate the cause, but to develop methods to prevent them from happening in the first place. We have been quite successful while also significantly reducing the amount of film traditionally used, eliminating web breaks, and improving machine throughput. (Amazing what a little science can do…) I have said that when you break it all down, you are really buying load containment. Your investment in a achieving a contained load is based on its value, criticality, and weight. That means that you consider the price of stretch film per wrapped pallet, vs per pound or roll. Considering it in those term puts everything on a level playing field. The type and quality of the pallet you use should be matched to your selection criteria rather than simply the cheapest – because it does matter.
There are pallets made from alternate materials such as plastic, some even have RFID tracking incorporated. They are superior, but they do represent additional cost, and the logistics of returning them add to your overhead. If your product’s weight and/or value are significant, and you are unsure which is right for you, there are resources that can evaluate your application and provide a pallet design for ultimate load containment, much the same way we do with stretch wrap. A friend and collaborator of mine, Laszlo Horvath is the Director of the Packaging and Unit Load Design school at the Virginia Tech College of Natural Resources and Environment and has made great strides in improving pallet design. Like me, he is all about the science of load containment.
Thanks for asking!
