Covestro and puren Advance a Bio-Circular Binder With Full ISCC PLUS Certification

Covestro and puren are advancing the use of bio-circular raw materials in polyurethane materials after puren achieved ISCC PLUS certification across its entire purenit® production at its Obermarchtal site in Germany.

Full ISCC PLUS Certification for purenit® Production

puren has commissioned a new production line at its Obermarchtal facility and certified its complete purenit® production to the ISCC PLUS standard.

The certification is an important step because it enables puren to use Covestro’s Desmodur® CQ MS binder containing bio-circular attributed raw materials. ISCC PLUS certification independently verifies the allocation of alternative raw materials through the supply chain under a mass-balance approach.

The companies describe the development as an example of value-chain collaboration aimed at supporting a more circular insulation industry.

Covestro's Bio-Circular Desmodur® CQ MS

Covestro supplies Desmodur® CQ MS, an MDI-based binder produced using bio-circular feedstocks through the mass-balance system.

The bio-circular raw materials are derived from waste and residues of biological origin. These feedstocks are introduced earlier in the production chain and their sustainability attributes are subsequently mathematically allocated to the final product.

According to Covestro, the approach allows puren to use a binder with a lower carbon footprint while keeping its existing processing conditions unchanged.

Combining Recycling With Bio-Circular Raw Materials

The collaboration brings together two approaches to resource efficiency.

purenit® is produced from polyurethane residual materials generated during PU production. These residual materials are processed through an adhesive-press process and converted into homogeneous boards.

The resulting functional material is based on rigid polyurethane and polyisocyanurate foam residues and has a density of approximately 550 kg/m³. It is designed to provide properties including pressure resistance, moisture resistance, dimensional stability and insulation performance.

By combining recovered PU materials with a binder based on bio-circular attributed feedstocks, the companies are applying circularity at two stages of the value chain.

Applications Across Construction and Transportation

purenit® is used across a range of applications where lightweight, durable and insulating materials are required.

Its applications include windows, doors, façades and base areas in construction, as well as bathrooms, wellness areas and outdoor kitchens. The material is also used for interior fit-outs in motorhomes, commercial vehicles and ships.

The companies say the material can be processed using standard woodworking equipment, including sawing, milling, drilling and gluing.

How the ISCC PLUS Mass-Balance Approach Works

The new development relies on the mass-balance principle rather than physically separating bio-circular raw materials throughout every stage of production.

Under this system, bio-circular feedstocks are introduced into the production chain and their corresponding sustainability attributes are allocated to selected products. ISCC PLUS provides independent verification of this allocation across the supply chain.

For puren, full certification of its purenit® production provides the basis for making the bio-circular raw-material attribution associated with the Desmodur® CQ MS binder.

This approach allows existing production infrastructure and processing methods to be maintained while incorporating alternative feedstocks.

New Lower-Footprint Product Planned for 2027

The certification is not the final stage of the collaboration.

During the inauguration of the new production line, puren announced that it is developing a new purenit® product using Desmodur® CQ MS as a binder. The product is currently planned for market launch in 2027.

The companies have not disclosed the production capacity or investment associated with the new line, while the expected numerical reduction in the finished product's carbon footprint has also not been specified.

Supporting Circularity in the Polyurethane Industry

The development highlights how chemical suppliers and downstream manufacturers can combine different circular-economy strategies.

Covestro contributes a binder based on bio-circular attributed feedstocks, while puren uses recovered polyurethane production residues as the basis for its functional boards. The resulting approach links recycled materials, alternative feedstocks and certified mass-balance production.

For the polyurethane industry, the collaboration demonstrates how circular-material concepts can be incorporated into commercial products while maintaining existing processing requirements.

Outlook for Bio-Circular Polyurethane Materials

The planned 2027 product launch will provide the next step in the collaboration between Covestro and puren.

With ISCC PLUS certification now covering puren's entire purenit® production, the companies have established the certification framework needed to use bio-circular attributed raw materials in the binder. The combination of recycled PU residues and mass-balanced bio-circular feedstocks reflects a broader industry move toward reducing reliance on conventional fossil-based resources and increasing circularity in polyurethane applications.