Valorisation of recovered wood fibres from post-consumer fibreboard and solid wood waste into wood fibre insulation boards through pilot-scale recycling

Abstract

Wood fibres recovered from post-consumer wood products represent an underutilised lignocellulosic resource with considerable potential for developing value-added bio-based insulation materials. Wood fibre insulation boards (WFIB) offer a renewable alternative to conventional insulation materials, and increasing the incorporation of recovered fibres can further improve resource efficiency and contribution to a circular bioeconomy. This study evaluates the utilisation of secondary (recovered) fibres derived from post-consumer fibreboard and solid wood waste at substitution rates of 25–100% for manufacturing flexible and hard wood fibre insulation boards. Recovered fibres were produced using moisture-modified thermo-mechanical pulping (mTMP) and steam treatment (ST), representing pilot-scale approaches to fibre recovery. Flexible insulation boards (50 kg/m³) were manufactured using bicomponent coPET/PET fibres as binders, while hard boards (115 and 200 kg/m³) were produced using polymeric methylene diphenyl diisocyanate (pMDI). Fibre morphology was characterised by particle size distribution analysis, and fracture surfaces were examined microscopically to investigate structure–property relationships. Panel performance was evaluated based on dimensional stability, mechanical properties, flame propagation behaviour, and thermal conductivity. Secondary fibres from post-consumer fibreboard exhibited 20–29% shorter mean fibre length and 55–60%higher fines content than virgin fibres, which was associated with reduced mechanical performance, particularly bending strength. Incorporation of secondary fibres did not result in a significant increase in flame propagation compared with virgin-fibre reference panels. Thermal conductivity was up to 4% lower in flexible insulation boards, while remaining similar to the virgin-fibre reference in hard boards. Overall, insulation boards containing 25% recovered fibreboard fibres or 100% recovered solid wood fibres showed physical and thermal performance similar to virgin-fibre reference panels. These findings demonstrate that recovered wood fibres have potential as high-value feedstocks for bio-based insulation materials, supporting the circular utilisation of post-consumer wood resources.

The authors' abstract, as published at the source. Industrial Crops and Products, 2026 · DOI ↗