Since already many years, foamed glass gravel is on the market as a loose fill thermal insulation. The thermal conductivity is roughly the double of the best cellular glass for the same compressive strength. This thermal conductivity is quite high but when there is enough space for a large thickness, we have an interesting material. The material is foamed from recycled glass with a minimum of treatment. Indeed, in principle a mixture of different glasses (different compositions) can be used without too much cleaning. Two foaming agents are well known in this perspective: glycerin and silicon carbide.

Producers:

• Glapor
• Misapor
• Ecoglas : this site has a webcam showing actual production
• Geocell Schaumglas
• Geoglas
• Refaglas

The business seems already well organized because the Czech company Refaglas is delivering also the glass powder with the requested particle size. Indeed, it makes sense to transport the ground glass to a foaming plant as close as possible to the customer to reduce transport cost. The grinding equipment will also be more efficiently used, reducing CAPEX of the different plants.

For the grinding equipment, I learned that today Hosakawa-Alpine is the major grinding equipment supplier, delivering a ball mill with efficient classifier.

It must be hard for a sales man to sell boards for floor insulation if gravel is still possible to install. But on the other hand, the difference between a gravel production line and a board line is only an extension with a new recipe, an annealing furnace and some finishing equipment. It must be very seductive for investors to make that relative small extension to increase the value of the output. And at the end, the invisible hand of the market competition will bring the price of high quality cellular glass down to about 200€ /m³, the price GLAPOR is handling since July 2015.

About this post, I got a reaction from Arjen Steiner:

There is another supplier/maufacturer with two factories in Germany. The name is Veriso (www.veriso.de). The sales office is in Berlin. The production sites are close to Hannover (www.schaumglas-husum.de) and close to Würzburg (www.schaumglas-steinach.de). The total production capacity is 130.000 m^3 per annum. Welcome to competition!