Case Study: Wood Pallet Mold Solution Required Redesign

Switching to kiln-dried pine can be an easy fix for hardwood pallet mold problems. The not-so-easy part is making sure the pine supports handling requirements with the same strength and durability.  

Problem
A customer identified a mold problem using hardwood pallets.

Design Limitations
Due to end-user requirements, the pallet had to remain a standard 48 x 40 size.

Strength Analysis
Running a PDS (pallet design system) analysis on the design, we replaced the hardwood with kiln-dried pine to address the mold issue. When switching the species to a less dense material such as pine, strength is sometimes an issue. In this case, strength numbers were close and we proceeded by testing a few sample pallets.

Sample Testing
Testing several pallet samples revealed issues with the design while using pine. The leadboards on the pallets were being pulled off or pushed back after just a few uses. We reviewed the pallet handling environment and discovered the customer's product didn't fit the perimeter of the pallet. This left 8" exposed on either the front or rear of the pallet. With no weight on the exposed leadboard, a forklift easily pulled the board off when not raised properly.

Redesign
We next tested more samples with butted leadboards to help support the product near its edge and prevent the leadboards from being pushed back. Unfortunately, the boards continued to be pulled off the pallets. After further study, a fourth stringer was added to the pallet to provide more nails. Samples were provided and they fixed the durability issues.

Results
In this particular case, the kiln-dried pine lumber was strong enough to hold the weight of the product while sitting on the floor (a static load). When the product was being transported on conveyor systems, forklifts or racks, the dynamic capacity of the pallet was under requirements and necessitated a modified pallet. The new pine pallet design has successfully reduced damaged caused by mold and handling issues.

End users often require product or raw materials to arrive on standard 48 x 40 wooden pallet even though it may not be the best fit. Problems such as over-hang or under-hand can damage product and pallets. Has this happened to you?

Ask us how pallet redesign could help solve your handling problems. Add your story in the comments below.

Post by: Jonathan Haynes, Sales Representative