Reusable packaging adds value

Tempered glass is nothing new. Thermal tempering of glass greatly reduces the likelihood of breakages as well as the risk of injuries. These are just some of the reasons why thermally tempered glass has been most commonly used over the years in car windscreens, where it sometimes proves to be a lifesaver. For glass packaging, however, this process had reached its limits – until now.

Controlled thermal treatment of a glass container consists essentially of rapid heating and cooling. The glass is first heated homogeneously (i.e. evenly over the cross-section) to a temperature of between 600 and 700 degrees Celsius. It is then shock-cooled by blowing air onto its surface. Because the glass surface cools first and contracts as it does so, the hardening causes compressive stress on the outer layers and tensile stress in the inner layer of the container’s cross-section.

Thermal hardening of glass containers could not be implemented in practice until now. Bottle design and quality imposed physical limits that made it impossible to produce tempered container glass profitably. But now, a solution is at hand: a new technology pioneered by the Vetropack Group. For almost ten years, research at the company's Innovation Centre has focused on a process for hardened lightweight glass bottles. The result: the Echovai technology – which, for the first time, enables thermally controlled hardening of glass bottles and makes their production economically viable.

The Echovai process places particularly high demands not only on the quality of the bottles but also on the production process and equipment. “Only high-quality, uniform bottles can be tempered successfully, because they are thermally treated to build up inner tension,” according to Daniel Egger, Head of Innovation at Vetropack. “What’s more, we adjust the entire curing process very precisely to the individual container and its shape. So this is a sophisticated, technologically demanding process – which is why we’ve opted for a phased rollout.”

30 percent less weight

The first phase began in 2019. Since then, several million of the bottles hardened with the new process have been sold to Mohrenbrauerei, the Austrian pilot customer, and subsequently refilled. The bottles produced by Vetropack for this Vorarlberg brewery deliver a decisive benefit: in the 0.33-litre returnables segment, the use of Echovai bottles (210 grams) saves around one third of the weight of the existing standard bottles (300 grams).

“We don't just look at the individual bottle; we consider – and optimise – returnables as a system,” Erich Jaquemar, Strategic Account Manager at Vetropack Austria explains. “That means we coordinate the bottle and crate design as well as the pallets and logistics. Only then can we generate maximum benefits for brand owners in terms of sustainability and total cost of ownership.”

Lower total cost of ownership, CO2 emissions fall to a quarter

With these goals in mind, the lightweight glass bottles were designed with less height than the standard – a factor that significantly impacts the logistics effort as well as the carbon footprint. Food retailing in Austria accepts pallets with a maximum height of 1.6 metres. With standard bottles, this allows a maximum of five crates to be stacked, whereas the Echovai crates can be stacked in six tiers.

 “This vastly reduces costs for logistics,” Jaquemar points out. “Customers save about one fifth of their costs per use cycle.” In the meantime, pilot customer Mohrenbrauerei has presented a life cycle assessment that illustrates the effects on logistics outlay. For the Echovai-bottled beer varieties, the CO2 savings were around 1,000 metric tons per year– so CO2 emissions per bottle dropped to just one quarter of the volume for the conventional 0.33-litre returnable bottle.

Alternative for manufacturers in the non-returnable segment

This innovative process is set to pave the way for a radical change in the market, because it is likely to promote the switch from non-returnable to returnable containers going forward. Echovai is not only an alternative for beverage producers who already sell their products in returnable containers. Especially for manufacturers in the non-returnable segment, the bottle weight is a deciding factor. Since returnable bottles have to last longer and are exposed to repeated stress, they previously had to be sturdier and heavier, and thus had to respect certain limitations in terms of design. Brand owners, however, usually want to keep the unique features of their bottle.

More robust – less abrasion

Another important attribute of these lightweight glass bottles is their robustness, which has now been proven. Extensive laboratory tests have verified the performance of the Echovai containers (as regards internal pressure resistance, impact resistance and other parameters). The results point to a significantly longer life span. In industrial use, too, the bottles break far less frequently: the reject rate during filling, at 0.14 percent, is significantly lower than the typical reject rate of between one and two percent for standard bottles. As an added benefit, the Echovai containers show hardly any wear on the contact surfaces (scuffing) after three years and up to twelve use cycles. “The bottle is robust, which is also a plus in terms of food safety,” Jaquemar comments.

After ten to twelve use cycles, the internal pressure values for the bottles correspond to the specification for new glass – which is not the case with standard bottles. The Echovai bottles also scored better results on the pendulum impact test than heavier conventional bottles. “Based on the test results and Echovai’s strong performance in the pilot project, we expect demand to rise sharply,” Jaquemar notes. Currently, Vetropack is still producing these stable lightweight glass containers exclusively at Pöchlarn, Austria. In the second phase, we are exploring the possibilities for installing Echovai technology at other locations. And for the third phase, Vetropack plans a wide-scale market launch with licensing of technologies and know-how to third parties as appropriate.

“In the long term, we’re aiming for a more user-friendly return and refill system with 100 per cent bottle reuse,” says Daniel Egger. “Also, we’re already working on a solution to optimise traceability of the Echovai bottles.” Thanks to a specific data matrix code on each bottle, any desired data will be linked to the product unit in future. This will make it possible to interlink different parts of the value chain that are currently viewed separately, and to track them along the entire supply chain – from production to bottling, all the way through to the end customer. Seen in this light, therefore, Echovai also heralds the dawn of a new era of digital interconnection.