While surface treatment might not be the first topic that comes to mind in label printing, it is as vital as any other. The success or failure of a print run can often be determined by the substrate. This is where surface treatment – be it corona treatment or static control – comes into play.

Surface treatment, like most technology, evolves. The need for it in 2025 is no different than it was in the 1950s when Verner Eisby established Vetaphone.

“The principle is simple,” says Kevin McKell, CSO, Vetaphone. “If you need a liquid, which could be ink, lacquer, or adhesive to adhere to a non-porous substrate, like plastic film or foil, you must ensure that the surface energy of both is closely matched, otherwise the liquid will not ‘wet out.’ Failure to do so will result in poor adhesion and a faulty end-product that will require a costly reprint. Whether a liquid ‘wets’ a material well or poorly depends on the chemical nature of the liquid and the substrate to which it is applied, and it is measured in dyne/cm.”  

There is an inherent downside to bypassing this process, too. “Skipping treatment, or failing to verify its effectiveness, leaves converters vulnerable to adhesion failures – everything from ink smearing to delamination – which leads to costly waste and dissatisfied customers,” explains Melissa Lang, senior vice president, Jemmco. “However, when treatment is done correctly and confirmed with reliable dyne testing, the payoff is significant: cleaner, sharper print quality, stronger and longer-lasting adhesion, less scrap, and greater profitability. Ultimately, effective surface treatment and testing are essential steps in protecting both the production process and the end product.”

“Simply put, the downside of not having optimal static control or automated static control is that productivity and safety decreases,” adds Joe Overman, president, TAKK Industries. “Rejections, downtime, and waste can increase.  When the capabilities of high performance Adaptive Intelligent static controls are implemented, the negative effects of static electricity are greatly eliminated.”

The higher the dyne level, the better the ink or lacquer will adhere to the substrate. The process of corona treatment modifies the molecular structure of the substrate by directing a high-frequency discharge at the surface from close-range. By disrupting the carbon molecule chains on the surface, oxygen is introduced with the result that the newly created carbonyl groups have higher surface energy. “This improves the chemical connectivity (dyne/cm) between the liquid and the substrate and allows better adhesion,” says McKell. “Different substrates have different native dyne levels, and different dyne levels are required for different applications. For example, water-based ink requires a higher dyne level than solvent-based, while coating and laminating can require even higher dyne levels.

“If the principle remains the same as ever, the technology that we see in today’s market is far more sophisticated in its control and capability,” adds McKell. “This is in response to the general trend across printed packaging for added-value techniques that make for greater on-shelf visual impact. These additional techniques have brought about the development of new substrates that have more complex chemistry and therefore require more careful and sophisticated processing.  

“With line speeds continuing to increase, securing adhesion of inks, lacquers, and adhesives to these new substrates require a detailed understanding and fine control of the surface treatment process if converters are to get it right first time, every time,” states McKell. 

To facilitate this process, Vetaphone has developed the VE1A-M model, which combines the higher speed and higher power (corona dosage) requirements. 

“There is a misconception in the industry that higher dosage requirement equates simply to higher power,” notes McKell. “What’s needed is carefully controlled application of the corona discharge so that the delicate substrate is not damaged. The key to this dates back to Verner Eisby’s original patent in the 1950s, which allows the generator to monitor the treatment process and optimize the correct frequency to ensure the most efficient discharge. This gives the best treatment to the substrate. The generator will automatically monitor the output and self-match to any material, altering the frequency to ensure an efficient discharge.”

Jemmco supports surface treatment through two key areas – treater sleeves and dyne testing. The JemmTron SRS Sleeve from Jemmco is designed for the demanding conditions of corona treating, with an optimized silicone formulation that offers excellent durability and ozone resistance. Its replaceable design means converters don’t need to send rollers out for recoating – operators can simply install a new sleeve in-house. 

“This translates to longer service life, fewer interruptions, and lower overall operating costs,” explains Lang. “On the quality assurance side, our ASTM-standard dyne pens and solutions – available from 30–70 dynes/cm – provide converters with a simple, affordable way to verify treatment and avoid costly adhesion problems. In addition to sleeves and testing tools, we also supply epoxy and ceramic corona treater rolls, replacement electrodes, and high-voltage wiring, giving converters a complete resource for maintaining their systems.”

For Vetaphone, one of the key benefits for optimizing this process is that it prevents excessive heat, which is vital when dealing with sensitive substrates.

So much for corona – but what about plasma?  This is a debate that is becoming more prominent in discussions with converters as packaging becomes increasingly sophisticated.  

“First, let me quickly explain the difference,” says McKell. “Where corona works in ambient conditions, plasma requires a controlled environment to allow dosage of inert gases that are fine-tuned to each substrate and its intended use. Plasma also produces higher dyne levels that are easier to maintain. This is particularly useful with a substrate like BOPP that is notoriously difficult to treat. For more than 95% of applications, corona treatment provides the perfect solution – but in special cases, where the substrate has a complex structure and downstream processing has specific requirements, the answer will be plasma grafting.”

So, which is better, corona or plasma? According to Vetaphone, the answer is they are not directly comparable. Effectively, the only similarity is that they are both surface treatment techniques, but each uses a different method. And while the corona process relies on the “free” ambient air, plasma requires far more investment in the technology and consumables (gas) that are required to make it work. This is why most plasma installations are with major international groups that use it for developing new packaging. Its value is both as an R&D tool and also in specialist commercial applications.

“I mentioned dyne levels earlier, and dyne drop-off is a function of the additives in each substrate that over time migrate back to the treated surface, resulting in the need for subsequent bump or boost treatment before further processing,” remarks McKell. “Getting this right is critical and the reason we invested in and opened our Test Lab facility back in 2020. It offers a unique opportunity to converters to run tests under controlled laboratory conditions prior to committing to the expense of commercial production. The same facilities are available to ink, lacquer, and substrate manufacturers, too, each of which is under close market scrutiny to ensure that their new products meet or exceed the current international standards.”

If the fundamental need for surface treatment is unchanged, the technology surrounding it has adapted to the changes in market demand over the years.  

Trending technologies

As the demands for surface treatment increase, suppliers have gone to great lengths to ensure proper runs on sensitive substrates. According to John Kalinowsky, electromechanical project engineer, Corotec, modern surface treatment systems are smaller and more compact, modular, and multi-functional. There are also portable treatment systems. Power density control and atmospheric pressure/room-temperature treatment have become hallmarks of these units, as well. 

“Custom systems and automation are commonplace today, too,” says Kalinowsky. “Data collection is present, and there is also an emphasis on environmental friendliness.”

With faster speeds and more intricate substrates, the demand for surface treatment is greater than ever. The downsides of not utilizing surface treatment are a greater possibility for defects, lower quality print, and more limited options for material and inks.

“Prepping the material with a corona surface treatment is essential on some combinations of materials and inks, and beneficial to many others,” notes Kalinowsky. “The treatment will reduce defects such as smudging, flaking, and fading, and can improve the print resolution across a range of printing techniques. Increased surface energy will also expand the options for inks that will reduce defects and provide more environmentally-friendly solutions. Corona treatment can also eliminate other surface pre-treatments, such as chemical primers, to reduce production costs and time.

“I would suspect that an ever-growing number of materials, inks, and adhesives has led to an increased demand for surface treatment to improve compatibility between substrates and inks/adhesives,” he adds.

For Jemmco, reliability and quality assurance are paramount for surface treatment success. “Converters are placing more emphasis on aftermarket solutions that extend equipment life and provide reliable, verifiable results,” notes Lang. “It’s not just about treating the surface –  it’s about confirming that treatment is effective, which is why quality testing tools are so critical.”

As in other segments of the label converting industry, automation has made its presence felt in surface treatment. “Automation has been a driver of innovation in static control surface treatment,” states TAKK’s Overman. 

“To further support the trend toward automation of control systems in label converting, TAKK Industries offers the advantages of our new X-Series Adaptive Intelligent Static Elimination systems, which deliver automated, precise static control for the label and packaging industry,” he adds. “The ability of automatic Adaptive Intelligent static controls to continuously monitor and ensure maximum static elimination enables in-process or finished goods to be produced at optimal throughput efficiency while minimizing unwanted waste or profit loss due to unsellable materials or products.”

TAKK Industries has engineered a number of products to support this market. The company’s X-Series Adaptive Intelligent Static Elimination systems offer automated, precise static control for
label converters. 

“These systems continuously monitor and adjust to reduce surface charges to the lowest level, ensuring optimal static elimination,” explains Overman. “The X-Series, a first-of-its-kind, features ultra-high ionization output and comes in three models for varying static elimination needs.”

To meet market demand for new solutions, Corotec has developed several products. Corotec specializes in custom corona treatment and plasma jet solutions. Based on the core technology in its power supplies, the company designs and engineers each system to meet the objectives of its customers.

The Compact Uni-Dyne is a compact unit, while Corotec also offers multi-functional units that feature a wide web with a switch kit for treating metallic and non-metallic substrates.  

Modularity is a key feature in the surface treatment market, as well. Corotec’s modular units include the Uni-Dyne with a tethered power supply. The Uni-Dyne also comes equipped with an easy-change electrode drawer.

For specialty treating systems, Corotec has unveiled automated cup treaters that feature plasma jet with an automated linear actuator system. Corotec also features HMI control panels for improved consistency and data collection. Ozone destruct units, ranging from 100 cfm to 7500 cfm, have been designed to virtually eliminate ozone emissions into the atmosphere, too.

Corotec recently launched its NoZone Ozone Destruction System, which is now available in the aforementioned sizes of 100 cfm to 7,500 cfm. Designed for demanding environments, such as corona treatment stations, x-ray and e-beam sterilization lines used in food packaging and medical device manufacturing, NoZone is touted as the smart solution for eliminating excess ozone before it becomes a safety or regulatory issue.

Built with safety and performance in mind, NoZone is engineered to tackle ozone at the source. Its negative pressure airflow design eliminates the risk of ozone leaks – even at poor duct connections – by pulling ozone-laden air through a specially designed canister before it ever reaches the blower. This not only ensures thorough ozone removal but also significantly prolongs blower life.

According to Corotec, what sets the NoZone system apart is its catalytic reaction process that destroys ozone molecules without degrading the catalyst, delivering tried and proven, consistent performance. Dual filtration at both the inlet and outlet keeps the system running efficiently, while optional monitoring tools like a manometer and ozone sensors offer real-time diagnostics of filter health and ozone concentration levels.

“With increasing OSHA and local environmental regulations limiting ozone emissions, having a reliable ozone destruction system is no longer optional – it’s essential,” says Kalinowsky. “Ozone is not only hazardous to human health when inhaled, but it also rapidly corrodes metal and sensitive equipment components. NoZone gives manufacturers peace of mind by reducing exhaust ozone to below 0.1 ppm, helping maintain both compliance and a safer work environment.”