2022: Year of glass

2022-10-18 | Corporate

Sixteen employees work in the glass production of the Anton Paar GmbH at the moment, one of them is an apprentice. All in all, they produce about 14,000 high-precision glass measuring cells every year. 

But this has not always been the case. About 20 years ago, Anton Paar purchased the glass pieces used for measuring instruments from external suppliers. After a price increase from a supplier, the aspiration for independence grew, and thus the first glassblower started at Anton Paar in 2002, and the establishment of glass production in the company began. “The core of our most important product line, the oscillating U-tube in the density measuring instruments, is made of glass. Thus we wanted to become independent from external suppliers,” says Gerhard Murer, whose product area the glass production belonged to when it was established. This so-called oscillating “U-tube” is a bent tube made of glass and used in digital density meters to measure the density of the sample liquid via oscillation.

One of the first employees of the glass production was Thomas Hillebrand, who started in 2005 and is still working in glass production. He works as a glass blower and glass instrument maker and is used to producing glass industrially. Nevertheless it was a challenge at first for him to produce the U-tubes. “It took me several months until I could produce the first functional oscillating U-tube. We are talking about glass walls which are only about 0.2 mm thick,” Thomas Hillebrand says about his starting time at Anton Paar. Back then, it was top priority to bring stability into serial production and improve manfuacturing machines and equipment. 

From individual challenges to serial production
After some years of experience, routine came into the glass production: Clear structures and processes are one secret of success, people are another. “It was and it is important for employees to specialize in certain work steps of the product because we are doing almost every production step in our glass production, from storage and cutting of raw material to glass processing, glass coating, and quality testing,” says Christian Krispel. He has been manager of glass production since 2007. Over the years, the glass production has grown successively, and the tasks have also expanded: Whereas only a few product groups were produced in the past, today there are many more varients of the oscillating U-tube and also various glass components for other product areas are produced. The most difficult part? “The U-tube for the DMA 5001 density meter definitely stands out, as its production involves 35 steps,” Thomas Hillebrand says. The production of this special U-tube takes about three weeks.

Highest precision
With Christian Krispel, apprenticeship trainings also came to glass production: Since 2007, glass instrument makers have been trained there. “There are hardly any skilled workers from this field in the labor market, that is why we decided to rely on internal future experts and train them ourselves,” says Christian Krispel. The apprenticeship profession is very rare nowadays, and it is only trained by a few companies in Austria.

If there is one thing that sets employees of the glass production apart, it is their precise way of working. “Glass is not very forgiving, so you need a high level of quality awareness, manual dexterity, high concentration, and the ability to work under pressure, if you want to work in glass production,” says Thomas Hillebrand. Right now, employees for the glass production are being sought.


Anton Paar not only produces glass parts, but it is also involved in the characterization of glass as well. These Anton Paar instruments are used for this purpose:

MCR and CTD 1000
Through the interaction of a rheometer (MCR series) and a convection heating chamber (CTD 1000) glass can be heated up to 1,000 °C. This enables the rheological characterization of melts. Glass samples with a higher melting temperature can be analyzed by the so-called dynamic-mechanical analysis in solid state, which can be used to determine how resistant the glass is, or how and at what temperature it softens. 

With high temperature rheometers (Furnace Rheometer System) from Anton Paar, glass can be characterized in a liquid state at temperatures up to 1,730 °C. Rheological parameters like the viscosity of melted glass can be determined. This has an impact on glass production. If the glass melt is too highly viscous (tough) during processing, gas inclusions cannot be removed, and the finished product will contain bubbles.