We told already that GLAPOR cellular glass is booming but now they have actually reached the top of Germany in a geometric way. Indeed, the GLAPOR cellular glass was selected as thermal insulation for the roof terrace on the Zugspitze, the highest mountain in Germany. The Zugspitze has a webcam, showing the nice neighbourhoud.

The climate is rather hard, which was one reason to choose GLAPOR cellular glass. Heavy sunshine during day and very low temperatures during night are difficult to resist for polymeric foam but are a piece of cake for cellular glass. Between cellular glass producers, GLAPOR was selected for his interesting price.

This price is possible because GLAPOR foams directly recycled glass without any expensive remelting at 1600°C. GLAPOR is installed in a larger thickness to compensate the higher thermal conductivity, which allows to work with larger dimensions (EUROPALLET size) to reduce labour cost.

Like can be observed in the picture, GLAPOR cellular glass is installed in hot liquid bitumen to guarantee a vapour tight roof, without any humidity absorption. More comments can be found in a GLAPOR document.

This project was sold and coached by the succesfull leader of the Austrian GLAPOR sales office, Aladin Hauft-Tulic. For a long time, Austria could not be seduced by cellular glass but Aladin seems to surf very good on the ecologic wave in Austria.

Recently we found cellular glass R&D in Romania, more specific at the Technical University in Timișoara. In the following, we mention two papers.

Arjen Steiner

The first paper describes a glass foaming process with fly ash and SiC. They reach densities down to 500 kg/m³, which is still quite high. The addition of fly ash is quite new in this perspective. In this system, not only glass but also fly ash is recycled. Leaching out tests confirm that these foams have enough chemical stability to be used as thermal insulation. Arjan Steiner made a thesis about foaming fly ash from municipal waste as already mentioned in a previous post.

In a second paper bottle and flat glass is foamed with 3 to 10% waste plaster. Also in this case, densities down to 500 kg/m³ (6% plaster) are reached with an acceptable leaching out test. These foams can probably  be used as cellular glass gravel thermal insulation, while thermal conductivities of 0.12 W/mK are reached.

The above papers convert a maximum of waste to ecologic cellular glass thermal insulation. Indeed fly ash, plaster waste and waste glass are crying to be recycled in a second life.

I like to dedicate this post to Danny Huwé , a Belgian journalist who was killed in the beginning of  the Romanian revolution, which was ignited in Timișoara, the city where the above R&D was done.

Cellular glass is mostly known as a black foam which smells as rotten eggs when crushed. Indeed most cellular glass is a closed cell structure, foamed with carbon, glycerin or silicon carbide.

But if we use “white” glass and a white foaming agent, we can produce a white foam. With the addition of pigments, all kind of colors can be given to the foam, like shown in the picture. Today, these foams are requested as “gravel” for decorative purposes and can be delivered by GLAPOR.

However, the use of colors in cellular glass is not new and is used for year by Polydros, a Spanish supplier of cellular glass. In this case, open cell foam (non-smelling) is used for hygienic purposes. For these products, some extra cost for a mineral pigment is a strong marketing weapon.