Open cell cellular glass is not a hot topic today. In a previous blog, we discussed a method to produce this open cell ware by opening closed cell cellular glass with hydrostatic pressure.

Partially open cell foam glass can be produced with CaCO3 as foaming agent but the cells are still partially closed. This product is less interesting because it can not be used where we need vapour tight cellular glass and it will induce problems where we need open cell ware. Acoustic absorption will be rather poor and also the ventilated thermal insulation system will face large pressure drops.

But it seems that waste glass can be foamed into >90% open cell material. I found the following leaflet on the website  of the Ngee Ann Polytechnic school in Singapore. This website gives a large contribution to green building and sustainable development. They focus especially on foaming waste glass boards without remelting like GLAPOR is doing in Europe.

In my opinion, this material is well suited to be used as dynamic insulation, like already mentioned in different posts about clean inside air and improved animal welfare  sheds. But it can alse serve as a cheap  fiber free acoustic absorption material like mentioned in the previous post.

It is clear, there is a future for open cell glass foams based on waste glass without remelting with the folowing characteristics.