Method of forming a fibrous product

A method of forming a molded fibrous product having a density of 5 to 100 kg/m3 and an air content of 90 to 99.5% by volume, said product containing fibers, which are bonded together essentially by hydrogen bonds and an inner part of the product is essentially free from thermoplastic bonding agents and thermoplastic fibers, said method comprising the steps of:

• foaming an aqueous suspension comprising natural fibers to provide a first fibrous foam,
• feeding the first fibrous foam into a mold,
• mechanically withdrawing a part of the water contained in the first fibrous foam to produce a solidified, moist fibrous composition, and
• evaporating water from the solidified, moist fibrous composition to produce a dry fibrous product,
• wherein
• water is removed from the fibrous foam by suction,
• the mold comprises an internal surface for receiving the fibrous foam and an opposite external surface, at least one side of the internal surface being made of permeable material adapted to retain fibrous material and to allow passage of water from the internal surface to the external surface, and
• the mold further comprising on the internal surface a protruding three-dimensional male part, covered on the internal surface with a permeable material, said male part corresponding to a cavity in the dry fibrous product, wherein the male part is covered on the internal surface with a permeable material
• the natural fibers have an average length of greater than 0.1 mm.