Method for producing a wooden composite board, and device for producing a wooden composite board

A method for producing a wood-based material panel, comprising:

• (a) producing a raw wood-based material panel that comprises a first lateral surface, a second lateral surface that extends parallel to the first lateral surface, and edge surfaces that connect the first and second lateral surfaces to each other,
• (b) applying a liquid containing a flame retardant to at least the first lateral surface, and
• (c) applying a negative pressure to the second lateral surface so that the liquid containing flame retardant is sucked into a subsurface of the raw wood-based material panel and/or applying an overpressure to the first lateral surface so that the liquid containing flame retardant is pressed into a subsurface of the raw wood-based material panel, resulting in the wood-based material panel,
• (d) wherein the liquid is an aqueous solution or suspension, and
• (e) at a point where the liquid containing flame retardant is applied, the concentration of flame retardant in the liquid at the surface temperature of the first lateral surface is higher than a saturation concentration of the flame retardant in the liquid.