Composite cellulosic products and processes for making same. In some embodiments, the composite cellulosic product can include a plurality of cellulosic substrates and an at least partially cured binder. Prior to curing, the binder can include a mixture formed by combining magnesium oxide, water, and magnesium chloride. A weight ratio of the magnesium oxide to the magnesium chloride in the binder can be at least 2.2:1 to 8.5:1.

A method and a plant for the production of material boards from at least one material which is spread to form a press mat and mixed with at least one binder curable by heat and/or pressure. The press mat is compressed in a double belt press with steel belts warmer than the press mat, and is heated by heat conduction. At least one cover layer resting against a steel belt is heated to a temperature above the curing temperature of the binder and cured at least partially. The uncured parts of the press mat are heated and cured in a downstream injection press by introducing tempered fluids to a temperature above the curing temperature of the binder. Fluids are introduced into or through the press mat through one or both cover layers. Also provided are a material board produced by a method and/or in such a plant.

A recycled board includes a plurality of fiber pieces and an adhesive. The plurality of fiber pieces are from recycled fabrics, and each has an average diameter of less than or equal to 10 mm. The adhesive includes at least one resin cured under the action of temperature, pressure, a curing agent, light rays or a combination thereof, and is mixed with the plurality of fiber pieces and molded. The total weight of the plurality of fiber pieces accounts for 50-80 wt % of the weight of the recycled board, and the weight of the adhesive accounts for 20-50 wt % of the weight of the recycled board.