In today’s fast-paced production environments, achieving strong and reliable adhesion on plastic and other non-porous materials is a critical part of the process. Whether printing, coating, laminating, or extruding, success depends on the substrate’s ability to bond effectively.
That’s where corona treatment comes in.
What is corona treatment?
Corona treatment is a surface modification process that increases the surface energy of materials (most commonly plastic films) by exposing them to a high-frequency electrical discharge; the corona. This exposure alters the molecular structure of the surface, making it more receptive to inks, coatings, adhesives and laminates.
Without treatment, many materials have low surface energy and are chemically inert. In practical terms, that means inks or glues won’t stick. This leads to poor print quality, coating defects or delamination.
Why is corona treatment essential?
Improved adhesion
The most important benefit of corona treatment is enhanced adhesion. By increasing surface energy, the material is able to form stronger bonds with inks and adhesives, resulting in better print quality, longer-lasting finishes and more reliable product performance.
Versatility across materials
Corona treatment can be used on a wide range of substrates, including:
- Polyethylene (PE)
- Polypropylene (PP)
- Polyester (PET)
- Foils
- Paper and paperboard
- Metalized films
This versatility makes it ideal for flexible packaging, labels, medical films, and more.
High-Speed production compatibility
Corona systems from Vetaphone are designed to integrate seamlessly into high-speed production lines. With robust engineering and easy maintenance, they support consistent performance with minimal downtime.
Cost effective
Corona treatment is a dry, chemical-free process, making it more environmentally friendly than alternatives. It is also energy efficient, with low operational costs over time – especially when using optimised systems and intelligent control interfaces.
The process in practice
A corona treater typically consists of:
- A high-frequency power supply
- Electrodes
- A grounded roller
- A discharge area (aka – air gap)
As the substrate passes through this area, the electrical discharge modifies its surface properties without affecting its bulk characteristics. The result is a surface that is ready for the next stage, whether that is printing, laminating, extruding or coating.
Engineered for reliability
At Vetaphone, our systems are built to perform reliably over the long term. With modular designs, easy access for maintenance, and local support teams around the globe, we make surface treatment simple, efficient, and stress-free.
And….
Corona treatment was invented in 1951 by Danish engineer Verner Eisby, founder of Vetaphone. Tasked with solving the adhesion issues associated with printing on plastic, he developed a controlled electrical discharge process that modified the surface of the film. This innovation became the foundation of surface treatment technology used across the industry today.
