Highly porous fibre foams: Potential end use applications

Foam assisted forming technology introduces new exciting opportunities to develop totally new types of sustainable wood fibre products. The technology allows highly porous and thick structures to be produced from fibres and it enables the exploitation of new raw material combinations extending the raw material base. Porous fibre structures can be made of any fibre or fibrous particle blends with or without additives that possess adequate level of bonding or adhesion in wet and dry state. Foam forming technology utilises small air bubbles containing aqueous foam as a process fluid. In the foam forming process fibres, water and foaming agent are mechanically mixed and the aqueous fibre-containing foam is generated with air content between 50-70%. The air bubbles effectively prevent flocculation of fibres. Highly porous, non-paper like materials can be produced by using small vacuums in the drainage phase and by using non-contact drying methods to prevent the collapse of the fibre network. This paper highlights VTT Technical Research Centre of Finland's foam forming research, shows research results and presents end product examples.