Experimental self-binding high-density fibreboard is produced of the grey alder (Alnus incana L. Moench) steam-exploded fibres without addition of synthetic adhesives. Milled grey alder chips are processed in steam-explosion unit by saturated steam under pressure of 3.2 MPa at temperature of 235 deg C for 1 min in a 0.5 l batch reactor. The steam-exploded fibres are pressed at 160 deg C temperature under 8 MPa pressure for 10 min in three steps. Properties, such as density, swelling in thickness, water absorption, bending strength, modulus of elasticity at bending, and internal bonding strength of the studied fibreboard samples are reported. Differences between the raw milled chippings and the exploded fibres are observed by scanning electron microscope. The study is focused on modified technical options of the steam-explosion unit supplied with two containers receiving different kinds of the exploded biomass farther used to obtain the hot-pressed boards. The cascade of the receivers is explained in a presently pending patent. The self-binding high-density fibreboard samples show the following properties comparable to commercial products: density of at least 1.35 g cmE-3, moisture content of 7.2%, swelling in thickness of 8.1%, water absorption of 3.2%, bending strength of 27 N mmE-2, modulus of elasticity of 6,259 N mmE-2, and internal bonding of 0.92 N mmE-2.

The growing popularity of wooden panels renders this market segment increasingly competitive. The article describes a new type of fibre boards e.g. the furniture production, developed in cooperation with ATB (Leibniz-Institute for Agricultural Engineering Potsdam-Bornim) by using a new method of raw material preparation and specific production technologies of ATB. The main raw material is preserved hemp (Cannabis sativa) stalks. The samples are made of raw materials with different wet-preservation time and varying types of binder. For the first time there is used main raw material with short time wet-preservation. Samples that are 8 mm thick correspond to a medium-density fibreboard and that are 16mm thick correspond to a low-density fibreboard, fitting in its mechanical properties to standard BS EN622. On ATB’s experimental processing line 1,200x800x8 mm and 1,200x800x16 mm size board samples are produced and the tests are performed to determine such parameters as bending strength, thickness swelling and thermal conductivity according to EU standard methods.