From nice-to-have to must-have

In our time, climate and environmentally friendly action and conscious decisions for sustainable packaging are increasing and forming decisive purchasing criteria. Accordingly, environmentally harmful manufacturing and disposal problems in the manufacture of packaging materials should be minimized and critical components of these materials that could be transferred to food or other filling substances eliminated. ACTEGA has been using PVC- and plasticizer-free sealants for beverage and food packaging for decades. They were first used back in the early 1980s for crown corks and aluminum closures, and have been utilized since 2006 for metal composite closures, since 2011 for Twist-Off® closures, and since 2016 for P/T closures as well. For the latter, PROVALIN® and ACTGreen® PROVALIN®, the world’s first PVC- and phthalate-free alternatives, were launched on the market. Exceeding the stringent EU regulations, they guaranteed a high level of food safety. Today, PROVALIN® can look back on a ten-year brand history. Initially, it had to develop step by step, but today it is a smashing success.

In the picture: PROVALIN® for Twist-Off® Closures

A look back

Although there had long been a need for PVC-free solutions for metal vacuum closures and the company had already had extensive experience developing PVC-free materials, the challenge was to find such a solution for Twist-Off® closures. Unlike with PVC-free crown caps or aluminum closures, new manufacturing equipment would have had to be designed specifically for these PVC-free metal vacuum closures. The conventional PVC Plastisol machines were not suitable for the newly developed materials. At this point, at the latest, it had become clear that the development would necessitate high investments on the part of the closure manufacturers, and many advised against it at the time. There was a hurdle that had to be overcome, which did not concern pure product development but required an adjustment of the environment in order to be successful.
Still, the ACTEGA team was certain that this was the right solution for the future. The use of PVC- and plasticizer-free sealing materials was of the utmost importance particularly when it came to canned foods for which metal vacuum closures were used, due to the issue of plasticizer residues in food. The EU regulations were tightened increasingly to prevent this from occurring. As a result, it became apparent that only plasticizer-free systems would be successful in the long run due to the toughening of migration limits alone. So it was essential to protect the PROVALIN® technology, and a patent application was filed in 2007.

Market launch

With an interested customer – Pano – and a purchaser – Dittmann – the conditions were optimal for ACTEGA to introduce the new product range. On the one hand, there was the technological knowhow and the required closure production equipment, and on the other, the requirements of a branded goods manufacturer. With these initiative partners, there was the technology push and market pull needed to lead the lengthy and complex development to a lasting and sustainable success. The cooperation with ACTEGA in Grevenbroich was another contributing factor. After all, a Twist-Off® closure consists not only of the metal shell and the sealing material, but also, among other things, of adhesive interior and exterior coatings. In addition, BPA-free materials had to be developed – another challenge, especially regarding the resistance to acidic filling materials. Today, such BPA-free pressure-sensitive coatings are available.

Research and development

The material formulations developed have to be intensively tested and inspected to ensure, among other things, their processability and functionality. While initially only one laboratory machine was available, today the ACTEGA team can look forward to new Sacmi machinery (ring liner technology), which will be available in 2021. With this machinery and the existing steam-vacuum capping machines, sterilization chambers, and pasteurization chambers, the complete cap production and filling processes can be mapped. This makes it possible to respond even faster, more effectively, and in a more targeted manner to constantly changing market requirements.
In this process, new challenges can continually arise. For example, on the part of the filling industry, where the topic of sterilization has been under discussion for some time, there is a demand to increase the temperature in order to shorten the sterilization time. The legislative side also keeps a close watch on things, for example, when FDA or the EU revaluates substances such as additives that come into contact with food, or migration limits shift

Application areas

The first area of application for PROVALIN® was oil-based niche products in the gourmet foods sector, including, for example, hot peppers in oil. Soon, cold-filled products were added. This presented yet another challenge, because filling is done in cold conditions. A new compound had to be developed that enabled the lids to be tight and the jars to be easy to open after being stored in the refrigerator. Technical questions about the sealing results on fast-running equipment had to be solved, as did issues concerning particularly soft materials that require less steam yet still seal equally well. Other requirements arising from the market are met by means of optimizations after intensive testing. In this way, the existing portfolio has been continuously improved and is constantly evolving.

From niche product to award winner

What began as a niche product is now an integral part of the market and has garnered considerable attention, which, among other things, has led to PROVALIN® winning several awards. In 2011, for example, PVC-free sealing systems from ACTEGA won the annual ALTANA Innovation Award. It received the prize for PROVALIN® and the corresponding coating systems. In the same year, the “metal screw cap Pano blue seal powered by PROVALIN®” won the German Packaging Award in the "Design, Features, Finishing” category. This was the first time that a PVC-free closure had become successfully established in this market segment. Seven years later, in 2018, the SOPURE 51 closure from Pelliconi with PROVALIN® received the Canmaker Gold Award for PVC-free Press-On Twist-Off® closure for baby food as part of the Can of the Year Award. Since 2020, this compound has been offered under the name ACTGreen® PROVALIN® for better identifiability as a green sealing material. Today, with more than two billion twist-off closures a year in the European market, the PVC-free closure has achieved general market penetration.

In the picture: [From left to right] Wilfried Lassek - Managing Director ACTEGA DS GmbH, Senior VP Metal Packaging Solutions, Dany Mängel - R&D PROVALIN®, Dr. Rüdiger Wittenberg - Head of Technology Group Compounds & Sealants

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