Manufacturing of wood-based panels takes sufficient place in wood processing industry around the World. An application and demand for such materials has been growing up. Wood-based panels are competitive with other plate materials. Wood fibreboard represents 25 % of manufacturing of all the wood-based panels in Europe. Usually synthetic adhesives are used for producing the wood fibreboard. These adhesives (usually phenol formaldehyde) are obtained from petroleum and gas products; therefore, they make 50 % of all the manufacturing costs of the boards. The cost of petroleum has a trend to increase; therefore the cost of wood-based panels could not be stable. Besides, synthetic adhesives are not environmentally friendly and there is a problem of utilization.
It is possible to obtain wood fibreboard without synthetic adhesives by means of using steam explosion (SE) pre-treatment. A saturated steam of 250 °C temperature makes certain pressure in hermetic reactor where wood chips are put. After 1-3 minutes the chips are decompressed within a split second and are converted to fibrous mass. During SE process wood chips structure gets broken up to cell wall level. Phenol and other adhesives are generated from wood without any additional chemicals. After the biomass is dried in the open air it can be hot-pressed and there is a possibility to obtain wood fibreboard material which competes with commercially obtained wood fibreboard. The board is called self-binding material because in the manufacturing process synthetic adhesives are not used.
Self-binding board samples hot-pressed from locally grown grey alder (Alnus incana (L.) Moench) at temperature 168–192 ˚C and pressure of 5–8 MPa for 10 min have a good form stability and other properties comparing to commercial boards.
Keywords: wood-based panels, steam explosion pre-treatment, self-binding board
Authors
Tupciauskas R.
Wood Materials and Technology, Department of Wood Processing, Latvian University of Agriculture, Jelgava
Latvian State Institute of Wood Chemistry, Riga, Latvia
Gravitis J.
Latvian State Institute of Wood Chemistry, Riga, Latvia
Veveris A.
Latvian State Institute of Wood Chemistry, Riga, Latvia
Tuherm H.
Department of Wood Processing, Latvian University of Agriculture, Jelgava
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