Production of wood fibre insulation boards with increased resistance to moisture and fungi from chemically modified fibres
Wood fibre products are among the most ecological insulation materials. Under certain conditions, however, condensation may precipitate in or on the surface of the insulating materials.
This leads to a failure of the insulation material and the formation of cold bridges, which in turn can increase condensation. As a result, the insulating materials lose their dimensional stability and insulating effect, as the pores necessary for the insulation are filled with water or are lost due to partial collapse (clumping) of the material. In addition, this can lead to infestation with moulds, which poses a considerable health risk.
Within the scope of the research project, fibrous materials are modified with siloxanes, N-methylol compounds and acetic anhydride using various processes. The modification is carried out either by treating the fibers in a MDF pilot plant or in a fiber reactor, or directly during fibre production in the refiner. Alternatively, wood chips are modified and then used for fibre production. The modification processes are adapted to existing processes with the aim of direct treatment in the refiner and of specifically adjusting the properties of the material in all phases of its processing. The chemical modification reduces the water absorption of the insulating materials, so that the insulating material retains its dimensional stability and thus its insulating effect under unfavourable climatic conditions and has greater resistance to fungal attack, especially mould.
The modified fibres and the fibre insulating materials produced from them are systematically characterized according to various methods, both with regard to their mechanical and technical properties and their insulating behaviour. The materials are also tested for resistance to moulds and wood-destroying fungi.