In the wet process, the raw material is grinded and then mixed into a mash with up to 98% water. This mash is then formed into a so-called fibre cake. After pressing most water out of the mat, the fibre cake is the cut and dried in the drying channel with temperatures between 160 to 220 °C. The addition of binders is usually not required, as the heating of the liquid lignin as part of the wood bonds the fibres during cooling. For special purposes (higher strength, hydrophobic properties), resins or bitumen-containing agents can be added. Thicker board are produced from gluing together several standard boards.
In the dry process, the fibres are dried directly after grinding and mixed with up to 4% resin, (e.g. PUR resin). For the production of flexible insulation boards, synthetic textile fibres or fibres from corn starch are added to the wood fibres. Subsequently, the fibres are sprinkled in desired thickness, pressed, hardened with a mixture of vapour and air and then cut, stacked and packed.
Production is subject to the regulations of the Industrial Emissions Directive (EU-IED, 2011) if the production capacity exceeds 600 m3 per day where one or more of the following wood-based panels are produced: fibreboard, particleboard or oriented strand board.