Are all Schott Duran reagent bottles made out of borosilicate glass?

The older ones are often made from Jena Glass and not Duran. But funny, they write it both on the label, but I have some with only Jena Glas on it. I believe...





[Edited on 25-7-2022 by Organikum]

Quote: Originally posted by Organikum

The older ones are often made from Jena Glass and not Duran. But funny, they write it both on the label, but I have some with only Jena Glas on it. I believe... [Edited on 25-7-2022 by Organikum]

Jena Glass Wikipedia

Jena Glass

The Jena Glass was the standard glass in the GDR and thats why in Germany we are blessed with huge amounts of cheap glassware, Anschütz-Thiele Vacuum Adapters go used for less then 15 €, Splash Heads 6 € and stuff most cannot identify anymore like steam distilation adapters for 3 €. Not on the meanwhile chronically overpriced Bay of course but at classifieds ("Ebay Kleinanzeigen") - also owned by Ebay but the mostly just hold it to prevent anybody else taking the niche.

The Jena glass has usually a characteristic dark, mostly black, sometimes dark blue "thread" in the glass which is not as many believe nowadays an imperfection but was put there on purpose as a sign of quality. Jena Glass is thinner then Pyrex or Duran, in special the grounded joints are much more prone to break. But the thinness has the advantage of superior heat-transfer, I like it very much. Caveat is that the thermal expansion coefficient is slightly different from Duran and it can become quite a challenge to get a vaccum tight grounded joint connection between the two. PTFE tape, the thin kind of 0,05 mm to 0,1 mm thickness is mostly the solution.

Attached pictures of a splash-head and of a steam distillation adapter made from Jena glass with the typical "stripes".

Quote: Originally posted by MadHatter

Jena glass (German: Jenaer Glas) is a shock- and heat-resistant glass used in scientific and technological applications, especially in chemistry. The glass was invented by Otto Schott in 1884 in Jena, Germany, where he had established Schott AG with Ernst Abbe and Carl Zeiss.[1] Jena glass is a borosilicate which, in early manufacture, contained added aluminum, magnesium, sodium, and zinc. It was a predecessor to other borosilicate glasses which came into wide use in the twentieth century, such as Pyrex. Sounds fairly tough even for that time.

Quote: Originally posted by Organikum

The Jena Glass was the standard glass in the GDR and thats why in Germany we are blessed with huge amounts of cheap glassware, Anschütz-Thiele Vacuum Adapters go used for less then 15 €, Splash Heads 6 € and stuff most cannot identify anymore like steam distilation adapters for 3 €. Not on the meanwhile chronically overpriced Bay of course but at classifieds ("Ebay Kleinanzeigen") - also owned by Ebay but the mostly just hold it to prevent anybody else taking the niche. The Jena glass has usually a characteristic dark, mostly black, sometimes dark blue "thread" in the glass which is not as many believe nowadays an imperfection but was put there on purpose as a sign of quality. Jena Glass is thinner then Pyrex or Duran, in special the grounded joints are much more prone to break. But the thinness has the advantage of superior heat-transfer, I like it very much. Caveat is that the thermal expansion coefficient is slightly different from Duran and it can become quite a challenge to get a vaccum tight grounded joint connection between the two. PTFE tape, the thin kind of 0,05 mm to 0,1 mm thickness is mostly the solution. Attached pictures of a splash-head and of a steam distillation adapter made from Jena glass with the typical "stripes".

Anschütz Thiele

The colored thread was a trademark and for fraud prevention as it seems to be very difficult to incorporate such a thing into the raw-material, what is mostly tubes which were delivered to the manufacturers and glassblowers of the time. And this way the glassblower as his customers could be sure to have gotten the real McCoy and not some cheap knockoff and there were plenty but none matched the quality of Schott for a long time, to be precise until Corning came up with Pyrex.

The Anschütz Thiele Vorstoß might possibly be called a Perkins Triangle in bloody Albion and its colonies after the great renaming due to WWI.

Here we got the culprit:



[Edited on 28-7-2022 by Organikum]



[Edited on 28-7-2022 by Organikum]

Quote: Originally posted by Organikum

The Anschütz Thiele Vorstoß might possibly be called a Perkins Triangle in bloody Albion and its colonies after the great renaming due to WWI.

Quote: Originally posted by VeritasC&E

Can I correctly assume that all Schott Duran reagent bottles (not to be confused with reaction flasks), including those produced in Germany until the early 90s, are made out of borosilicate glass of one type or another?

Quote: Originally posted by Herr Haber

Great topic, I learned a lot. I am surprised by Organicum's picture as I always understood tbat Duran is a glass made by Schott. I'm confused by Duran and Jena being both present on the flask. Maybe it's just the place of manufacture in that case ?

Quote: Originally posted by Chemetix

The history and evolution of the borosilicate glass industry is complex and still evolving. The one bend in the Main river near Wertheim where Schott is situated in holds one of the worlds most concentrated areas of glass technology. Along Otto-Schott strasse is where Schott glass now called DWK operates from. Across the road is Lenz, just down the road is Brand. Just along from Otto-Schott strasse is Ernst-Abbe Strasse where you can find Schuller and Glaswerk Wertheim and opposite them is Witeg Labortechnik. Then nearby is Geissler Glas instrumente, Wertlab and Fraunhofer ISC in Wurzburg. There's more I've missed but you get the picture. Within the scientific glassblowing industry there are times when you notice moulding and manufacturing details that seem to indicate that the branding decal doesn't match what you could have sworn you saw before. It would be no surprise if there was some crossover between the sites and some overflow production that makes it's way to other manufacturers. But the glass itself is formulated as and sold as cullet mainly by The now called DWK. Cullet is glass tech speak for big chunks of pure glass for melting down and turning into items. When borosilicate glass was in more demand than it is now there were other larger manufactures like TGI and Jena who produced tubing, flasks and finished items. They more than likely started with Schott cullet. The only other manufacturer to note in Europe is Kavalier just across the border from the Thuringia region in the Czech republic. They produce Simax borosilicate glass. It's often noticeably different in its' glass formulation as it can give off a light blue glow at the end of the tube or the rim of a beaker or bottle. From a glass blowers perspective the glass gets a lot less viscous when hot, probably to aid the molding of objects such as beakers, flasks and bottles. No doubt we'll continue to see companies be absorbed and manufacturing be passed to different sites as demand changes along with company directions. But borosilicate glass and it's current formulation is likely to remain very consistent as it's a precisely tuned one that balances workability with long term chemical and physical durability.

Quote: Originally posted by pneumatician

in production now... https://www.duran-bottle-system.com/