Corona Discharge Treatment Within the Packaging Industry
The Packaging industry has for a long time used Corona surface treatment (also known as Corona discharge treatment) to improve ink wetting and adhesion properties for printing, laminating and other requirements.
Corona treatment is basically an electro chemical process that occurs when the electrical discharge of Corona treatment meets the slightly waxy or oily material surface in the presence of oxygen (air). The waxes and oils migrate to the material’s surface after extrusion or indeed moulding, where they lay – simply getting in the way of inks, adhesives and bonding. Corona treatment is used to clear these from the surface as well as provide a slightly oxidised face that is much more receptive to inks and adhesives etc.
Corona treatment is a must-have process for a myriad of Packaging manufacturing applications, for instance:
- Food manufacturers needing to freshen or prepare surfaces prior to laminating – this could be laminating materials for food sachets or cartons such as those used for fruit juice or soups;
- Plastic Packaging manufacturers needing to prepare surfaces of carrier bags prior to printing;
- Product containers such as oils of cosmetics are often Corona treated to aid the bonding of applied labels and other container decoration;
- The Label manufacturing industry has become a major user of narrow web Corona treatment systems for labels in Polypropylene, Polyethylene and other materials, usually for optimum print quality of speed of wetting and drying;
- Extruded films and webs, for which Corona discharge treatment has long been the most efficient and cost effective solution.
We have had a number of customers, old and new, contacting us as they move to using modern water based ink and adhesives, often as replacements for their existing solvent type processes. Typically the water based solutions require further improvements to the surface energy levels over and above those used in their solvent process. This sometimes needs a Corona treatment system upgrade which can be a new system or tweaks and subtle modifications to their existing equipment. It’s not unusual to find the customer has issues or gremlins undermining the actual treatment level achieved, even if their system still operates up to full (max) power. A short phone conversation often leads to genuine improvements in the treatment level applied, sometimes a site visit and physical checks on the system is the best option.
Corona treatment is – and should be – a very controllable, manageable and safe process. This relies on a few key criteria and getting these right makes the world of difference; it goes without saying that well designed equipment and ongoing technical support will be key to a peaceful life!
As UK partners for AFS & Softal, with experience of all the other Brands, we can safely say that their sound design principles, ingenuity, top quality and reliability means they are respected by every other manufacturer.
If you’re in Packaging industry and you need help with surface treatment, do call us on +44 (0)1844 355221 or email us at firstname.lastname@example.org