Rough roads mean parts are in constant motion. Even when product is generously spaced, shocks and vibration can compress separating materials, letting surfaces touch and leaving marks. Adding more separation might prevent touching, but reduces volume utilization in the truck, pushing up shipping costs. Even if contact is avoided, vibration means movement against the dunnage material. That’s a problem with many types of parts, but especially when appearance is critical, as with Class A automotive components.
Polyethylene foam is widely used in dunnage. It compresses and recovers readily, so does a good job of absorbing shocks and vibration. Unfortunately though, it’s open-cell structure tends to rub, creating marks on paint and in metal and plastic.
For holding fragile parts and those where surface appearance is critical, cross-linked polyethylene (XLPE) foam performs much better. A closed-cell structure means no edges to abrade part surfaces, so coatings and finishes remain pristine, yet it’s still resilient enough to protect against shock and vibration.
Another benefit of XLPE is the ease with which it’s cut and shaped, as Merryweather demonstrated when producing inserts for specialized dunnage racking. That helps reduce spacing between parts while still ensuring they won’t touch or rub. Tighter intra-part spacing translates to improved weight or load utilization and the low density of XPLE foam also means the excess weight being shipped is minimized.
XLPE foam is available in a range of colors, which can be beneficial for easy product identification, and as a closed-cell foam, is waterproof if left uncovered while outdoors. Unlike wood, it doesn’t splinter, and has no sharp edges, so there’s little risk of people being injured while loading or unloading parts.
Minimizing shipping costs involves maximizing volume and weight utilization in the truck, but that’s not enough if product gets damaged in transit. By choosing the right material for dunnage it’s possible to pack individual pieces tightly yet still be confident in them arriving undamaged after even a long cross country journey. Precision cut XLPE foam is the material to use.