Our quality challenge to recycle more used glass


We are committed to using more than 65% external recycled material for our Glass Mineral Wool by 2025. The figure of 65% recycled cullet — made from high quality used bottles and glass — is an optimal level for our fibrising processes, furnaces and quality of our fibres.

However, by going higher, for example, using 75% cullet across our plants the advantages become greater.

“Using high levels of recycled material saves huge amounts of manufacturing energy — compared to processing raw virgin materials — and that means saving more emissions and reducing the embodied carbon of our products,” says Vincent Briard, our Director of Sustainability.

“But in the case of our Glass Mineral Wool this positive outcome depends on finding plenty of quality cullet and in many countries the resources are simply not available in the volumes we require.

“This is a challenge we will be addressing over the next five years and we are examining all options available.”

For example, we are looking at increasing access to more used glass. In Stupino, Russia, for example there was zero glass collection in 2013. Today after working with the local municipality we now collect 350 tonnes of used glass as raw material at our Stupino plant every year via 10 local government supported collection and recycling points.

In the UK we partnered with the waste management company Veolia to build a used glass facility at our St Helens plant which cleans, sorts and refines around 60,000 tonnes of used bottles and jars into high quality cullet every year. 

Using high levels of recycled material saves energy, emissions and reduces the embodied carbon of our products.
Vincent Briard, Director of Sustainability


Among the recent examples of achievement at Heraklith has been the elimination of significant quantities of production waste that used to end up in landfill.

This has been achieved thanks to cooperation between our plants at Simbach and St Egidien in Germany and our central technical department.

Material dust, produced during the manufacture of Heraklith Wood Wool multilayer panels, can now be separated and the Expanded Polystyrene (EPS) and Wood Wool residues collected for recycling.

The Rock Mineral Wool sawdust from Simbach in Bavaria is sent to St Egidien in Saxony where it is cleanly and efficiently processed into a new Rock Mineral Wool product.

The process now saves more than 1,700 tonnes of waste which previously went to landfill.


The project is not only a commendable example of great cooperation between two plants with different technologies; it also marks a significant contribution to enabling a circular economy and reducing the amount of waste that goes into landfill.

“This is a huge step forward for Wood Wool and shows the incredible strength of the group to work together to find solutions — especially the collaboration between the plants and the central technical teams during the years of development,” says Joachim Wieltschnig, our Technical Director Wood Wool.


Knauf Insulation has rolled out a pilot scrap recycling initiative for modular building companies in the Netherlands who use our Glass Mineral Wool.

The process is provided for a small fixed fee every month. Our system measures the scrap produced at a customer’s site and automatically tells our partner company when it is ready for collection. The cut-offs are then picked up and recycled into bricks and tiles.

The scheme saves customers costs, gives them peace of mind that waste is being dealt with responsibly and lowers the environmental impact of their products.


The briquetting facility in the plant enables the reuse of production waste to achieve zero waste at the site.

We are taking back a remarkable amount of Mineral Wool off-cuts from a local panel producer as well as wooden pallets. The briquetting plant in Surdulica enables the closing of the recycling loop for production waste and material coming back from customers. Plans for the future will enable us to increase those volumes significantly.

We recycle waste from wash water — there is no waste to landfill — and it is used as raw material for a brick manufacturer. We also replaced high-quality city water for the plant with well water from a deep drill to our site.

We take back Rock Mineral Wool waste from local panel producers, our OEM customers.

In 2020 we reused 6,270 pallets which saved 87 tonnes of timber.

We have reduced our landfill waste at Visé by 80% in the past six years.



We have set ourselves an indicative 2025 target of using more than 25% external recycled material for our Rock Mineral Wool production. Almost all of our plants briquette production waste and feed it back into the manufacturing process, but we are aiming to increase the use of waste from our customers’ construction sites which are normally large scale projects — such as commercial buildings — where the waste is relatively straightforward to process. We also want to increase our use of ‘slag’ — waste from the steel industry — that can also be recycled.


The plastic packaging we use is strong, which allows us to compress our products and get more packs per truck than before. For example, 5,800 m2 of 50 mm Mineral Plus can be delivered in one truck with an 80 m3 capacity. The same amount of Rock Mineral Wool would need 3.6 trips.

Compressed packs save fuel and emissions, but still require a lot of plastic. For a pallet of 300 kg of Glass Mineral Wool, for example, you would need up to 6 kg of virgin plastic to wrap the product. In our new sustainability strategy we have set a 2025 target to reduce our virgin plastic film packaging usage by more than 25% and where possible between 25% and 50% of our plastic film will be taken back from our customers and recycled.

We are working with our suppliers to explore new ways to make our packaging more and more sustainable, such as continuing to reduce packaging weight, while maintaining the same level of compression strength.

Just recycling 30% of plastic would cut the embodied carbon of our products by 1% — we are committed to a 15% reduction by 2025.

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In Europe 25 million cubic metres of timber are used every year for pallets and packaging. We provide a service in the Netherlands and UK, where we collect and reuse customer pallets.



Read our Annual Review 2020!