Two boxes can look identical from the outside and behave completely differently, because everything that determines whether the part arrives intact happens on the inside. Dunnage is not an accessory to a returnable box; on a lot of projects it is the majority of the engineering.
Start with the part, not the box
Decide the contact points before deciding the container. Where can the part be touched, where must it not be touched, and how does a person lift it? Those three answers set the layout. A dunnage set designed from the box inwards always ends up with a contact where nobody wanted one.
Location versus support
Location stops the part moving. Support stops the part deflecting. They are often confused, and one component frequently does both badly. A part held only at its base will rock at the top; a part supported everywhere will be slow to load. The usual compromise is firm location at two points and gentle support under the centre of mass, and it is worth drawing those two roles separately.
Drop-in, lift-out, slide-in
How the operator places the part decides the cycle time, and cycle time decides whether the dunnage gets used properly. A drop-in set with clearance is fast and allows a little movement. A slide-in set is slower and holds much better. A lift-out set needs vertical clearance above the box, which is fine in a low-bay plant and impossible under a mezzanine. Choose this before the geometry, not after.
Materials for the dunnage itself
The container and the dunnage do not have to be the same material. Board dunnage is light and cheap and wears at contact points. Foam is gentle and compresses over time, changing the fit. Machined plastic is durable and expensive. Hybrid sets, using board for structure and a soft facing only where the part touches, are the usual answer and are usually the cheapest way to get both properties.
Making the wear points replaceable
Something in every dunnage set wears out first, usually the soft facing or the locating pin. If that component can be replaced without replacing the set, the dunnage life matches the box life. If it cannot, a whole set gets scrapped because of a worn pad. Designing for the wear point is the single highest-value decision in the whole exercise.
Loading errors and how to make them impossible
Operators load parts the wrong way round, especially on a busy shift. The reliable answers are asymmetric geometry, meaning the part physically will not go in backwards, and a clear visual marker. Instruction cards help and decay. Anything that relies on the operator reading something is a temporary fix.
Keeping the set with the box
A dunnage set that can be lifted out will be lifted out, used elsewhere and lost. Captive, tethered or keyed sets survive. This is the failure mode that kills more returnable programmes than damage does, and it is covered further in keeping dunnage with the box.
Testing before a fleet
Build one set, run it for a month on the real route, and inspect the part and the dunnage afterwards. Look for shine marks on the part where the dunnage touches, which show you where the movement is. Ten of those marks will tell you more about the design than any amount of analysis.
Getting the operator’s view first
Before drawing anything, watch someone load the current packaging for an hour. Where they put their hands, where they hesitate, which operation they do twice. That hour produces more design input than any specification, and it usually reveals a step that no procedure mentions, such as turning the part over on the bench before it goes in.
Then build the first set with the operator and let them use it for a week before it is signed off. The changes they ask for are usually small, obvious and invisible from a desk, and they are the difference between a set that is used properly and one that is quietly worked around.
What we can do
We design PP honeycomb board boxes together with the dunnage inside them, and where the set is steel or machined we design the box around it. Send the part, the annual volume and a description of how it is lifted, and we will propose a layout before quoting a box.