Question 1

Why do corrugated cartons pop open after hot melt application?

Accepted Answer

Cartons pop open primarily due to an open time mismatch, insufficient compression time on the auto-packer, or thermal shock during transit. Using a formulation with higher hot tack or upgrading from EVA to metallocene ensures a permanent fiber-tearing bond.

Question 2

What is the difference between EVA and Metallocene hot melt adhesives?

Accepted Answer

EVA is a cost-effective, versatile copolymer suitable for standard corrugated board. Metallocene polyolefin offers a lower polymer density (yielding 15-20% more glue mileage per kg), resists nozzle charring and thermal degradation at 170°C, and provides superior bonding on highly recycled boards and freezer packaging.

Question 3

What is the recommended application temperature for industrial packaging hot melt?

Accepted Answer

Standard packaging hot melt adhesives operate between 150°C and 175°C. Low-melt variants operate at 120°C to 135°C to conserve energy and prevent heat deformation on delicate substrates.