Formal transit testing exists and has its place, but most of what a packaging decision needs can be established without it. The point of a test is not to produce a certificate; it is to find out where the box fails before the customer does. That is achievable with ordinary equipment.
The drop test
Load the box to its rated weight, lift it to the height it will realistically be handled at, and drop it onto each face and each corner in turn. Note where it deforms and whether the closure stays shut. The corners usually tell you more than the faces.
The stack test
Load a stack to the planned height with the planned weight, leave it for the planned duration, and measure the height at the start and the end. Then strip it and look at the bottom box for permanent set. Creep is slow and a one-day test will not show it, so give it the real duration.
The route test
Put instrumented or simply well-documented loads on the actual lane and inspect on arrival. This finds the things a laboratory will not: the transfer point with the rough floor, the vehicle with the different internal height, the route that gets handled twice more than expected.
What to record
Photographs before dispatch and on arrival, dimensions before and after, and a note of exactly where any damage is. Without the before-and-after the arrival condition cannot be interpreted, because there is nothing to compare it to.
How many samples
Three is usually enough to see whether a failure is consistent or random. One is an anecdote and ten is unnecessary unless the result is near a limit. Where three behave differently, the process is more variable than the box.
What to do with the result
Where the box fails at a specific feature, that feature gets reinforced. Where it fails generally, the load case was wrong – usually the height or the duration. Where it passes with room to spare, the specification can probably come down, which is the outcome people forget to look for.
What a failure tells you
Where the box fails at a corner, the corner needs reinforcement – a formed vertical edge, a corner post, or a change in how the panel folds. Where it fails across a panel, the wall specification is wrong for the load. Where the closure opens, the closure is the problem, not the board.
Recording which of the three happened is most of the value of the test. A report that says “box failed” leads to a heavier board, which is the expensive answer to most of these problems and the correct answer to almost none of them.
How often to repeat it
When the part changes, when the box changes, when the route changes, and otherwise rarely. Testing is cheap but not free, and a fleet that is working does not need to be re-tested on a schedule. It needs to be re-tested when something that affects the load case changes.
What to do with a pass
Where a box passes with margin, the specification can probably come down – a thinner wall, less reinforcement, a lighter base. That is the outcome people forget to look for, and it is often worth more than the damage avoidance. Where it passes narrowly, note the load case it was tested against, because that is the limit the fleet is running to.
What we can do
We build PP corrugated turnover boxes and can send sample boxes for exactly this sort of test before any commitment. Tell us the load and the route. What a passed test leads to is how to run a real lane trial.