This paper, about a year ago published is another proof that the race for the best cellular glass, based on waste glass without remelting is really going on. The research is done at the university in Sofia in Bulgaria. Indeed, East Europe is doing a lot of effort for cellular glass today.

The paper reports on the use of glycerin and water glass for the foaming of the container glass. What do we learn?

• They start from 6000 cm²/g glass powder while another source mentions 8000cm²/g.
• Glycerin is used as foaming agent.
• Also water glass is needed although the role is not clear.

But they also report a thermal conductivity of 0.02 W/mK. I doubt that this is possible and for that reason, I have my doubts about the measuring system C-Therm TCI. These dynamic cheaper systems are popular these days but BELGLAS advises to work with the stationary systems for thermal conductivity measurements. In a future blog, we will report again on that subject.

I am looking forward to measure a real 0.042 W/mK on a cellular glass plate, foamed from not remelted waste glass. In my opinion, that is the way to go.