Knowledge Base
2.0 Gluing Defect Types
Most corrugated box plants know that they get returned orders from their customers, but very few know the details of what the specific problems are that cause the order to be returned. Claims such as the boxes were stuck together, or the glue tab failed don’t help box makers identify the true problem.
Below are the 11 major types of gluing problems found in corrugated box plants that cause customers to complain and return orders. The first 7 problems typically result in glue joint failure, while the last 4 problems typically result in boxes being stuck shut or stuck together.
Glue Joint Failure:
No Glue: No glue has been applied to the box.
Mistimed glue: The glue has either started early or late, and the glue tab or quarter panel is missing glue in the intended adhesion area.
Glue Lines Missing: The adhesive dispensing system has not placed enough glue beads onto the corrugated box.
Scrap on Glue Tab: Scrap pieces of corrugated box are riding on the glue tab, have been glued on, and will subsequently fall off during the folding process, thus exposing a glue tab with missing glue.
Damaged Boxes: Glue tab has been damaged in the flexo-folder gluer, or in the handling process. The damaged glue tab will not have sufficient strength to hold the box together.
Skewed Box: Because the box is crooked or skewed, glue placement is not in the correct location. (Note: There would also likely be a folding problem as well)
Insufficient Glue: Glue beads have become very thin, and there is no a longer sufficient volume of adhesive to create the necessary bond.
Boxes Stuck Together:
Too Much Glue: Too much adhesive was applied to the corrugated box, and excess glue will now be forced outside the glue tab adhesion area. The excess glue outside the adhesion area will cause the box to be either stuck shut or stuck to other boxes.
Mistimed Glue: The glue has either started early or late, and the glue tab or quarter panel is missing glue in the intended adhesion area. (Particularly critical during quarter panel gluing)
Short Sheets: The corrugated sheet has been cut too short, resulting in the glue beads moving relative to the sheet’s edge.
Lateral Sheet Shift: The corrugated sheet shifted laterally in the machine, changing the placement and registration of the adhesive relative to the glue tab edge
