Night delivery stacking: compression in the roll cage

At 02:15 the roll cages come off the tail lift three high, and the bottom cage has been carrying 54 kg since the depot loaded it at nine the previous evening. The cartons of pads inside are flat on one face. Nobody notices until the day shift opens one and finds sheets with a permanent crease down the middle and a thickness that has gone from 3 mm to 2.2 mm.

Compression is the quiet failure of pad logistics. Nothing breaks, nothing leaks, and the product is subtly worse for the rest of its life.

What compression does to a pad

An absorbent sheet works because of the void space between fibres and, in a polymer grade, between particles. Squash it flat and you reduce the volume available for liquid and the rate at which liquid can travel sideways. A pad that has been compressed by a third will still absorb, but it will absorb more slowly and hold less at the edges, which is exactly the behaviour that produces free liquid in a tray.

The damage is permanent. Fibres that have been crushed for twelve hours under load do not spring back to the original loft, even after a week in a warm store.

There is a visible sign, which helps on a receiving dock. A compressed sheet looks glossy on the face and slightly translucent at the crease. Bend a corner and it stays bent instead of lifting back. That is a sheet that has been under a cage since the depot.

Loading a cage for a night run

The fix belongs at the depot, and it is a stacking rule rather than a purchase specification:

• Pads never in the bottom third of a cage.
• No cage stacked more than two high, and never on a cage containing cartons.
• Cartons stood on edge, not flat, if they must go low.
• A rigid divider between the pad cartons and anything metal.

If pads must travel low, put them in the cage that goes on the tail lift last, which spends the least time under load.

Weight distribution inside the cage matters as much as stack height. A cage loaded with heavy chilled boxes at the front and pads behind will lean, and the pads take the shear. Load heavy at the base, pads at the top, and strap the cage even for a short run.

Receiving checks in two minutes

Open one carton per delivery and measure the stack height with a rule. Compare with the nominal on the specification. A 20 percent loss is a rejected pallet, not a note in the file, because you cannot recover the performance later.

Look at the carton corners as well. A crushed corner means point loading somewhere in the stack, and the sheets underneath it will be the worst affected. Photograph the cage before unloading; it is the only evidence you will have when the supplier asks how it happened.

The usage forecast that drifted

One store saw its pad usage climb by a fifth over three months with no change in sales. The cause was a delivery that had started arriving flat-packed at the bottom of the cage. Staff found the sheets harder to separate and used two at a time to get the same result. Two pads per tray for three months is a substantial overspend, and it was invisible because the pads still looked like pads.

The other symptom is a dispenser that jams. Compressed sheets feed two at a time, the operator pulls three to clear it, and the count drifts further. If your dispenser starts jamming on a delivery day rather than randomly, look at the cage before you look at the dispenser.

Set the stacking rule with the carrier in writing, check one carton on arrival, and keep the rule on the depot wall. It costs nothing and it protects a product that has no way of complaining. Storage and handling limits, including compression, are listed in the fresh food pad guide.