Bowing OSB Pallet
Tech Center to the Rescue: The Case of the Bowing OSB Pallet
The Problem: a load of oriented strand board (OSB) pallets were bowing.
The Nelson Technical Center encountered a wood pallet problem that was not only causing a big headache but was also costing our customer valuable time and money. Nobody liked that. Turns out, heat and cold were to blame.
Empty corrugated boxes do not sit flat on this pallet due to the bowing OSB top deck.
The Pallet: OSB Top Deck
The pallet was a solid wood block-style pallet with an OSB panel for the top deck. Usually, a bowing pallet is not a big issue. Once you load product on most pallets, the weight will flatten out any bowing. In this case, an empty single-bulk corrugated box was to be glued to the panel deck pallet.
When the box touched the middle of the pallet, it was lifted 1/2" from the pallet on the sides. Unable to glue the box, the customer could not ship the empty boxes to the next location for loading in product.
The problem was new. The customer had never before experienced this issue. Nelson went to the customer site to inspect the load.
The Culprit: Cold Weather
Some onsite troubleshooting led to the following discoveries. One discovery in particular proved to be crucial for identifying the issue. Here is what we found:
The box did indeed lift about 1/2� on the sides.
All pallets from older loads (some were still at the customer warehouse) were slightly bowed too.
Some of the older pallets had plywood panels rather than OSB.
Both plywood and OSB panel pallets revealed bowing issues.
The pallets were flat when assembled.
The problem load was made during a very cold month.
The Solution: HT Assembly Changes
After further investigation into the effect of the heat-treating (HT) process on OSB, The Nelson Technical Center discovered that OSB is likely to bow during the (HT) process. Since these pallets were made in very cold weather, we suspected the bow was worse because they were in the HT process longer than the previous pallet loads.
Here is how we fixed the problem:
By removing the OSB panels, the base pallet immediately returned to a flat pallet.
The OSB top panel was then reattached to the flat pallet for a flat OSB pallet.
Going forward, the OSB panel is added AFTER the base wood pallet goes through the HT process.
The Follow-Up: Success
Reworking the load worked. Since changing up the order of heat treatment vs OSB attachment during the manufacturing process, no further bowing issues have occurred.
OSB Panels Bowing?
Have bowed or warped pallets ever caused your company problems? Let's connect. Tell us about your problem or ask questions below.
Updated: 06/19/2025 | Published: 09/12/2013
by John Clarke
on Case Studies