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Finland: Biomaterials VTT Develops Fire Retardant Coating Based on Noncellulose

Editor: Alexander Stark

A spray- or brush-applied fire retardant coating made from nanocellulose is well suited for improving the fire properties of wood-based materials, reports Finland-based company VTT. It reduces the access of oxygen to the surface, thus significantly inhibiting combustion.

Hefcel-coated wood (left) and untreated wood (right) after 30 seconds flame test.
Hefcel-coated wood (left) and untreated wood (right) after 30 seconds flame test.
(Bild: VTT)

Espoo/Finland — According to VTT, their new coating is set to revolutionize the market for coatings used in the fire retardant treatment of construction materials. The company has found an effective production method for the coating through piloting and is currently seeking a partner to commercialise the technology.

The fire retardant coating is based on Hefcel technology (High-Consistency Enzymatic Fibrillation of Cellulose) developed and patented by the company. Hefcel technology enables the efficient and cost-effective production of nanocellulose from wood-based pulp, the developers claim. The solids content of Hefcel materials was ten times the solids content achieved with traditional manufacturing methods. This made them well suited for uses where low water content is preferred: for example, paints and coatings, packaging and composites.

Nanocellulose has a natural tendency to adhere to wood and to form an airtight film on the surface of wood and various other small particles such as pigments. This makes nanocellulose-based coatings highly suitable for the protective treatment of wood surfaces. Combining Hefcel nanocellulose with organic pigments forms a spray- or brush-applied, airtight film that prevents the access of oxygen through the coating and at the same time significantly inhibits combustion.

The idea was developed by VTT research scientists Vesa Kunnari and Jaakko Pere as part of the Design Driven Value Chains in the World of Cellulose (DWoC) project funded by Tekes (now Business Finland).