University of Bayreuth, Press Release No. 032/2023, 27.03.2023

On the way to unbreakable and at the same time lightweight glass bottles

The Keylab Glass Technology at the University of Bayreuth is currently researching the production of glass bottles that do not break. They are using a process that is also used for smartphone displays.

Glass bottles are superior to other types of packaging in various respects and usually have a more favourable eco-balance. And yet many people prefer to reach for PET bottles or metal cans on the supermarket shelf. This is because glass bottles have two disadvantages: they are heavier and break if they fall awkwardly. A glass bottle that doesn't break when dropped and is significantly lighter - that was the goal with which the founder of the start-up "Soulbottles", Paul Kupfer, approached the University of Bayreuth almost three years ago.

Glass that does not break has existed before: such a process had been developed in the GDR, but production was discontinued a few years after the fall of the Wall. However, the team at the Keylab Glass Technology at the University of Bayreuth, led by Prof. Dr.-Ing. Thorsten Gerdes, is now building on this process. "The 'trick' to increasing strength is to treat the bottles in a molten salt bath in which an ion exchange takes place," Gerdes explains.  "This is a process that is also used for all smartphone displays to increase the chance that the filigree glass panes will survive a fall here too."

Smartphone displays, however, unlike drinking bottles, are quite different in terms of manufacturing. "We have developed a new process that is not only faster but also has a significantly improved eco-balance," explains Gerdes. This new process is also to be patented.

Prof. Dr.-Ing. Thorsten Gerdes' team was able to prove that this procedure for increasing strength also works for drinking bottles in the last two years in the ZIM project (Central Innovation Programme for SMEs) together with the special plant manufacturer Füller Glastechnologe Vertriebs-GmbH. The "Strongbottles" project is funded by the Federal Ministry for Economic Affairs and Energy and runs until the end of August.

However, as the results are very promising, the business partner "Soulproducts" has now launched a crowdfunding campaign ( to finance the production plant. 

Prof. Dr.-Ing. Thorsten Gerdes was on hand as keynote speaker at the crowdfunding kick-off event. "As an engineer, development is naturally close to my heart," he says. But when our research results in a product that is ready for the market, that's even better."

Refillable glass drinking bottles, which are designed to last a very long time, are becoming increasingly popular as society becomes more aware of the need to save resources by avoiding waste. For years, this awareness has led to a trend reversal towards greater sustainability in product packaging, to which the "Strongbottle" will contribute in the future. The company "Soulproducts" wants to bring the bottle, which was developed together with the University of Bayreuth, to the market as the "Soulbottle Ultraglass".

Gerdes Rennecke

Prof. Dr.-Ing. Thorsten Gerdes

Telefon: +49 (0)921 / 55-6504

Jennifer Opel

Jennifer Opel (im Mutterschutz / Elternzeit)Stellv. Pressesprecherin

Telefon: +49 (0)921 / 55-5357