Why PET Strapping Damages Unprotected Carton Edges

Quick answer

PET strapping damages unprotected carton edges when strap tension, sharp strap edges, or load shift concentrates force on a small board area. Raising carton ECT alone often fails if the strap still bites the same unprotected corner.

Inspect the failure mode

Look for crushed corners, cut liner, strap imprint through print, and whether damage appears at tensioning, during transit, or after re-strapping at a hub.

Check tension and strap selection

Confirm strap width, thickness, tension setting, and seal type. Over-tension on soft single-wall cartons cuts edges even when the strap grade is appropriate for the load weight.

Add or correct edge protection

Use edge board or buckled U-protectors under strap paths. Protectors must be wide enough for the strap and long enough to cover the contact zone on each vertical edge.

Review pallet pattern

Overhang, voids, and leaning stacks let straps migrate into weaker panels. Photograph the finished pallet before stretch wrap hides the strap path.

Validate corrections

Trial one change set—protector + tension window + wrap—then ship a monitored lot. Do not change board grade, strap, and pallet pattern in the same uncontrolled trial.

RFQ

Damaged SKU photos; strap type/tension; pallet pattern

Carton board/ECT; edge-protector proposal

Load weight; route; re-strap exposure

Trial quantity and acceptance photos

Related PackTrades Knowledge

What Is a Buckled U-Edge Protector?, PET Strapping vs PP Strapping for Packaging Loads, Edge Board Specs for Furniture and Appliance Export, How to Source PP Strapping from China.