Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Glasstec 2014: Lead-free glass decor

07.10.2014

Whether on baby bottles, beer mugs or perfume bottles, imprints on glass consist mainly of lead oxide. Fraunhofer researchers have developed printing inks for glass that do not contain any toxic elements. At the glasstec tradefair from October 21st to 24th in Düsseldorf, they are going to present the new imprints (Hall 15, Booth A33).

The perfume bottles seem almost like little works of art: made of stained glass, elegantly formed and decorated with imprints. But the decorative graphics and fonts that are emblazoned on them really make an impression: They are made of special glasses containing up to 50 percent by weight of lead oxide, which can be dangerous to one’s health.


The lead oxide free colors have a high color brilliance and are chemically resistant.

© Fraunhofer ISC / K. Selsam-Geißler

To decorate the bottles, manufacturers grind these special glasses together with inorganic pigments, print them as pastes on the base glass and melt them on. As a result, the colors are just as durable as the glass itself. Beer mugs, baby bottles and pharmaceutical glass products, such as vials, are decorated and labeled in about like the perfume bottles are.

In the future, a new EU Directive will banish the potentially unhealthy lead oxide from the logos. But this is far from simple: in order for the printing inks to hold permanently, they have to be made of chemically resistant glass. However, they usually contain a lot of silicon dioxide, and therefore have to be melted above 1600 degrees Celsius – a temperature that the base glass would not withstand without becoming deformed.

The added lead oxide lowers the melting temperature to below 600 degrees Celsius, thereby creating viable processing conditions. As a last resort, manufacturers are replacing the lead oxide with bismuth oxide. However, that, too, is problematic: Bismuth is dangerous to one’s health as well as to the environment. It also multiplies the price of the imprints.

Colorful decor without pollutants

A new development by researchers at the Fraunhofer Institute for Silicate Research ISC in Würzburg and the Forschungsgemeinschaft Technik und Glas e.V. FTG can change that. "We have developed lead oxide free decorative paints, which do perfectly well without toxic substances," says Anika Deinhardt, researcher at the ISC. "They are easy to process, have high color brilliance and are chemically resistant. In addition, they do not contain any rare or expensive elements."

The basis of these novel decorative paints is a glass that consists mainly of zinc oxide. Further constituents are aluminum oxide, boron oxide and silicon dioxide. The researchers gave this basic glass system – almost as a short form of all the elements – the name ZABS. Zinc oxide ensures that this glass already melts below 650 degrees Celsius. It therefore takes over the task that previously fell to the lead oxide.

"Through various other additives, we are able to modify ZABS further and adapt it very well to the respective requirements," explains Deinhardt. As a result, the scientist and her colleagues were able, for example, to reduce the melting temperature of a special glass to 580 degrees Celsius. In a further step, they are working to produce glasses with a processing temperature of only 540 degrees Celsius. At glasstec, they will present their work, along with samples (Hall 15, Booth A33).

As the glass, so the decorative color

Another point which the scientists have to consider: The industry partners use different types of glass for their products. If the glasses are heated, they expand at different rates – experts speak here of the thermal expansion coefficients (TEC) for the respective glass. In order for the imprints to not flake off, they have to expand similar to the glass on which they are applied.

This already works for soda-lime glass, from which drinking glass and container glass are made, for example. The researchers hope that in six months, they will also have adapted the new colors to borosilicate glass, from which vials, laboratory glassware and household goods, such as casserole dishes or tea and coffee pots, for example, are made.

On behalf of the Forschungsgemeinschaft Technik und Glas e. V. FTG, the Fraunhofer researchers are developing a catalog of all the developed low-melting glasses and their properties. Thus, these systems can be used for future developments – and decorative pastes will be able to be adapted with little effort to the requirements of the manufacturers.

Anika Deinhardt | Fraunhofer-Institute
Further information:
http://www.fraunhofer.de/en/press/research-news/2014/october/lead-free-glass-decor.html

More articles from Trade Fair News:

nachricht High Resolution Laser Structuring of Thin Films at LOPEC 2017
21.03.2017 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Open ecosystem for smart assistance systems
20.03.2017 | Fraunhofer-Institut für Arbeitswirtschaft und Organisation IAO

All articles from Trade Fair News >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>