According to the Corrugated Packaging Alliance, “in 2012, 91 percent (29 million tons) of the corrugated packaging used in the U.S. was successfully recovered for recycling, maintaining its top position as the most-recycled packaging material.”
While finding fewer boxes in landfills is great for the environment, the higher recycled content of corrugated containers can make it difficult for end of line packaging operations. That’s because packaging tape doesn’t always stick well to recycled corrugated cartons.
Why is that?
Three factors come into play:
The structure of the box fibers.
Take, for example, a brand new corrugated box. Here, virgin kraft fibers are used to create a top sheet that is porous, providing areas where the adhesive can be pressed down and entangled with the fibers, the staple length of which are longer and more entwined than recycled fibers. With recycled cartons, the fibers have been chopped up and repulped. This results in smaller fibers that must be packed tightly together with fillers to create a top sheet. These tightly packed fibers create a less porous surface, which makes it difficult for the tape’s adhesive to penetrate.
The tape’s ability to bond to the surface.
The adhesive on packaging tape is designed to entangle deep within the fibers of the box. Given the intricacies of sticking to smaller fibers, many tape manufacturers have designed specialized packaging tapes for sealing recycled corrugated cartons.
Proper application of the tape.
Pressure-sensitive packaging tapes are just that – they require some type of force to properly bond to the surface. This pressure is particularly important when sealing cases, but even more so when sealing less porous surfaces such as recycled corrugated cartons.