Boxes opening in transit or filling (pop-opens)
High severitySymptoms
Client reports open boxes; the bond looked fine in production
Probable causes
- Insufficient or misplaced adhesive
- board memory (stiff board levering)
- adhesive wrong for the destination climate (cold)
- insufficient pre-fold
The Print Guy · 2026-10-05
Other problems in this category
Folder-gluer · TPG-255
Flap not bonding with white glue (PVA/cold glue)
Boxes opening at erection or filling; glue peeling cleanly off the surface
Folder-gluer · TPG-256
Hotmelt not bonding (cooling before closure)
Hotmelt bead solidifying without grabbing the other face; peels off like plastic
Folder-gluer · TPG-259
Skewed box or misaligned flaps (fishtailing)
Closed carton comes out rhomboid; flaps don't meet
Folder-gluer · TPG-261
Crash-lock bottom malformed
Bottom won't erect or its glue points fail
Folder-gluer · TPG-265
Stepped hotmelt temperature profile (optimal setup)
Inconsistent bead, stringing, short open time or degradation with a seemingly 'fine' setup
Folder-gluer · TPG-266
Char in the hotmelt tank
Black specks in the bead; nozzles clogging often; burnt smell; darkened adhesive