In order to meet the demands of innovative packaging design, paper converting companies have started manufacturing cartons for the food industry, boxes for electronic equipment, promotional folders, boxes for high-class perfumery and cosmetics with new materials such as PET, PP and polythene paper:
- PET is transparent and versatile and is typically used for medium/high range products
- Polypropylene (PP) is resistant, soft to the touch and has excellent transparency and is replacing PVC in the manufacture of collapsible cartons
- paper + PE is typically used in the food industry and especially for frozen food boxes.
These materials have created new glue and ink adhesion problems compared to traditional cardboard boxes.
Folder and gluer lines
In folder-gluer lines for the manufacture of collapsible boxes, the glue is applied along the folding edge of the box, in well-defined strips with a maximum width of 10 mm. Due to the smaller surface area, the plasma nozzle treatment system is more effective than the corona treatment.
Implementation of the air plasma treatment on folder-gluer lines is simple and requires little maintenance. The torch is mounted in line before application of the glue to activate the surface and help glue adhesion.
The treatment is also available with two nozzles for gluing multiple points according to the box design.
- increases the surface tension and eliminates any impurities thereby increasing glue adhesion
- does not produce ozone and only needs compressed air to direct the discharge on the zone to be treated
- reduces the amount of hot-melt glue needed or uses cheaper cold glues with excellent results.