Corrugated Ink Adhesion Testing: The Tape Test and the Standards Behind It
The ink on a box has one job: stay there. Through printing, stacking, shipping, and a customer s warehouse, the print must survive — and it usually fails in one of two ways: rub-off (surface abrasion) or lift-off (poor adhesion to the board). Corrugated s rough surface makes adhesion testing different from folding carton testing, and the standards define what "good enough" means.
The Scenario: The Ink That Came Off in the Rain
A customer complained that box logos rubbed off during humid shipping — the ink had decent rub resistance dry, but moisture exposure weakened the bond. The plant added a wet-rub test to its QC and switched to a moisture-resistant ink for that account. Complaints stopped, and the wet-rub test became standard for all humid-lane customers.
Pain Points
- Dry rub tests miss moisture-related adhesion failures — the failure mode in humid shipping.
- Tape tests done inconsistently (different tape, pressure, speed) produce unreliable results.
- Corrugated s rough surface makes some ink lift look worse than it is — interpretation needs a standard.
- Without a standard, QC and customer disagree on what acceptable adhesion means.
The Solution: The Adhesion Test Toolbox
Three tests cover adhesion, with the standards that make results comparable:
1. The tape test for lift-off (ASTM D3359 method) A pressure-sensitive tape is applied to the printed surface, pressed consistently, and pulled at a defined angle. The percentage of ink lifted classifies adhesion (5B = no lift, 0B = complete lift). On corrugated, tape test the flattest printable area and compare within the same board grade.
2. Rub testing for surface abrasion (Sutherland-style) A weighted felt block rubs the print for a defined number of cycles; the ink transfer onto the felt and the print s appearance grade the rub resistance. Test dry, and add a wet-rub variant for humid lanes — moisture is a separate failure mode.
3. Cross-hatch on flat areas for detailed diagnosis The cross-hatch tape test (scribe a grid, tape, pull) localizes adhesion failure to specific zones — useful when a design element fails while the rest holds.
4. Build the QC standard and log it Define pass criteria per ink and board grade (e.g., "≥4B tape test, no visible rub after 50 dry cycles"), test at first article and per shift, and log results. The standard turns adhesion from argument into data.
The Result: Wet-Rub Test Saves the Account
The humid-lane account moved to moisture-resistant ink validated by the new wet-rub test, and adhesion complaints stopped. The plant now runs tape + dry rub + wet rub on every first article, per-shift on high-volume jobs, and its adhesion log shows a 90% reduction in print complaints within two quarters.