Abstract: Disclosed are panels of medium density fibreboard (MDF). The panels comprise wood fibres, the largest dimension of which is 7 mm or below, pressed together with an adhesive. The panels are of a large and thin type, having an aspect ratio of at least 100 and a surface area of at least 1 m2. Typical problems associated with such large and thin panels, e.g. warping behaviour, are addressed by employing wood fibres are made of acetylated wood.

Abstract: The invention is directed to a process for the continuous acetylation of wood elements. The process particularly combines a batchwise impregnation step, with a continuous reaction step. In order to realize this, a collection step is built-in, so as to allow batches of impregnated wood elements to be fed into a reactor in a continuous manner. Very high acetylation contents can be obtained, at a level that had not been achievable before in a continuous and non-catalyzed acetylation process.

Abstract: The invention is directed to a process for the continuous acetylation of wood elements. The process particularly combines a batchwise impregnation step, with a continuous reaction step. In order to realize this, a collection step is built-in, so as to allow batches of impregnated wood elements to be fed into a reactor in a continuous manner. Very high acetylation contents can be obtained, at a level that had not been achievable before in a continuous and non-catalyzed acetylation process.

Abstract: A process for acetylation of wood having a density of above 400 kg/m3, particularly, of Southern Yellow Pine, allows the production of acetylated wood having higher acetylation levels, such as an acetyl content of at least 20% by weight. The acetylated wood has also a low residual acetic acid content, in particular, lower than 1% by weight. The invention is particularly useful for acetylation on industrial scale of pieces of solid wood, preferably, of wood beams.

Abstract: A reactor system for the modification of lignocellulosic materials comprises a reaction vessel, a vacuum connection and an inlet and/or outlet connected to a gas flow loop connected to a heat exchanger and at least one fluid circulation device. Particularly, gas flow loop is arranged so as to allow gas circulation over the diameter of the reaction vessel. The gas flow loop preferably includes a gas distribution device, such as a distribution plate.

Abstract: Disclosed is a reactor system for the modification of lignocellulosic materials. According to the invention, the system comprises a reaction vessel, a vacuum connection and an inlet and/or outlet connected to a gas flow loop connected to a heat exchanger and at least one fluid circulation device. Particularly, gas flow loop is arranged so as to allow gas circulation over the diameter of the reaction vessel. The gas flow loop preferably includes a gas distribution device, such as a distribution plate.

Abstract: The present invention describes a process for the acetylation of wood comprising treating wood with an acetylation agent comprising acetic anhydride and/or acetic acid and subjecting to acetylation conditions, wherein the acetylation reaction is carried out in the presence of an acetylation catalyst comprising a salt of an organic acid, wherein the organic acid is a carboxylic acid, phenol or a substituted phenol, wherein the carboxylic acid is chosen from the list consisting of aromatic carboxylic acids, medium chain saturated monocarboxylic acids, keto acids, dicarboxylic acids, tricarboxylic acids, hydroxy acids, amino acids and derivatives thereof.

Abstract: A system for treating wood (30), comprising: —a treatment vessel (14) configured to receive at least one wood stack (4) for treatment, and —a stack holding system (2) for holding a wood stack (4), the stack holding system (2) comprising: —a frame (6), configured to support the wood stack (4); —a first element (8), connected to the frame (6) near an upper side of said frame (6), configured to exert a first, downward force on the wood stack (4); and —a second element (10), connected to the frame (6) near a lower side of said frame (6), configured to exert a second force on the wood stack (4) in a direction opposite said first force. The invention also comprises a method for treating wood, using a system for treating wood according to the invention.

Abstract: Disclosed is a process for the acetylation of wood, wherein the wood is impregnated with acetylation fluid and heated in stages. It is thereby secured that an acetylation reaction is conducted at a temperature above the boiling temperature of the acetylation fluid, at a stage where the impregnated wood is largely devoid of free acetylation fluid (i.e., acetylation fluid not retained in the wood matrix or in capillaries). Preferably, the process is conducted in a plant having conveyors, such as transportation screws, in the zones in which the separate heating steps are conducted.

Abstract: Disclosed is a process for the acetylation of wood, wherein the wood is impregnated with acetylation fluid and heated in stages. It is thereby secured that an acetylation reaction is conducted at a temperature above the boiling temperature of the acetylation fluid, at a stage where the impregnated wood is largely devoid of free acetylation fluid (i.e., acetylation fluid not retained in the wood matrix or in capillaries). Preferably, the process is conducted in a plant having conveyors, such as transportation screws, in the zones in which the separate heating steps are conducted.

Abstract: Disclosed is a reactor system for the modification of lignocellulosic materials. According to the invention, the system comprises a reaction vessel, a vacuum connection and an inlet and/or outlet connected to a gas flow loop connected to a heat exchanger and at least one fluid circulation device. Particularly, gas flow loop is arranged so as to allow gas circulation over the diameter of the reaction vessel. The gas flow loop preferably includes a gas distribution device, such as a distribution plate.

Abstract: The invention relates to a process for acetylation of wood having a density of above 400 kg/m3, particularly, of Southern Yellow Pine, and acetylated wood obtainable by this method. The described acetylation process allows the production of acetylated wood having higher acetylation levels, such as an acetyl content of at least 20% by weight. The acetylated wood has also a low residual acetic acid content, in particular, lower than 1% by weight. The invention is particularly useful for acetylation on industrial scale of pieces of solid wood, preferably, of wood beams.

Abstract: The invention is directed to a process for the continuous acetylation of wood elements. The process particularly combines a batchwise impregnation step, with a continuous reaction step. In order to realize this, a collection step is built-in, so as to allow batches of impregnated wood elements to be fed into a reactor in a continuous manner. Very high acetylation contents can be obtained, at a level that had not been achievable before in a continuous and non-catalyzed acetylation process.

Abstract: Disclosed are panels of medium density fibreboard (MDF). The panels comprise wood fibres, the largest dimension of which is 7 mm or below, pressed together with an adhesive. The panels are of a large and thin type, having an aspect ratio of at least 100 and a surface area of at least 1 m2. Typical problems associated with such large and thin panels, e.g. warping behaviour, are addressed by employing wood fibres are made of acetylated wood.