Today’s carton packaging is made from sheets that are printed, finished, cut, and folded in a folding machine and usually glued by the manufacturer (pre-gluing). This is accomplished on high-performance pre-gluing machines with speeds up to 600 m/min. The glue that is used, cold glue, adheres without difficulty directly on bare paperboard material, but if that material already has a quality finish (such as a UV coating or laminated film), the places that will later be glued usually need to be roughened using an elaborate mechanical process (mechanical miller, sandpaper, brushes) in separate machinery. Otherwise, those spots must be masked before sealing.
Integrating Openair® Plasma technology significantly simplifies the process. Plasma jets are installed directly in high-speed pre-gluing machines where they pretreat the folding carton in the glue seam areas. The resulting increase in surface tension is enough to dramatically increase adhesion capacity; the cold glue that is generally used bonds regardless of the coating, varnish or surface sealing.