STEAMING OF BEECH WOOD, COLOUR HOMOGENISATION AND THE MANAGEMENT OF THE WASTE WATER

Robert NEMETH
Dr - University of West Hungary, Faculty of Wood Sciences
Address: H-9400, Sopron, Bajcsy-Zs. U. 4.
E-mail: nemethr@fmk.nyme.hu

Laszlo TOLVAJ
Prof.Dr - University of West Hungary, Faculty of Wood Sciences
Address: H-9400, Sopron, Bajcsy-Zs. U. 4.
E-mail: tolla@fmk.nyme.hu

Sandor MOLNAR
Prof.Dr - University of West Hungary, Faculty of Wood Sciences
Address: H-9400, Sopron, Bajcsy-Zs. U. 4.
E-mail: smolnar@fmk.nyme.hu

Tamas RETFALVI
Dr - University of West Hungary, Faculty of Forestry
Address: H-9400, Sopron, Bajcsy-Zs. U. 4.
E-mail: tretfalvi@emk.nyme.hu

Levente ALBERT
Prof.Dr - University of West Hungary, Faculty of Forestry
Address: H-9400, Sopron, Bajcsy-Zs. U. 4.
E-mail: lalbert@emk.nyme.hu

Abstract:European beech forests have more and more trees which have irregular red heartwood. The great colour difference between light and red heartwood needs colour homogenisation.
The objective of the investigation was to analyse the influence of different schemes of steaming on the colour of red heartwood in sawn timber, compared to the surrounding light sapwood. Based on laboratory steaming tests industrial schedules were developed to establish desired levels of colour.
The effect of the initial moisture content on steaming was also examined. The investigation of this parameter is important because in some cases there is long time passed between felling the trees and steaming the timber and the sawn timber looses the moisture fast.
The colour stability of steamed timber is important. For this purpose steamed samples were weathered behind window glass to investigate the indoor stability of the colour of the steamed timber.
The condensed water gained during the steaming and cooking processes of beech wood has to be considered as waste and needs relevant management. In order to be able to undertake effective actions in the management of waste water the chemical compounds, the pH value, the COD value, and the conductivity have to be determined. It is well known from literature that the composition of the condensed water depends on the applied temperature as well. In order to show the effect of temperature and the mixing of wood species, which is very often the case in industrial plants, waste waters gained during different steaming processes were investigated with up-to-date GC-MS and TLC techniques. Four different types of industrial waste waters were analysed: 2 samples collected in a Hungarian plant, and 2 samples collected in the Austrian plant MIKO. The objective of this part of the work was to analyse the chemical composition and pH value of the waste water originated from different steaming processes in two different industrial plants, using different steaming chambers. Thus to get data about the variability of the chemical composition of the waste waters. The second objective was to find an environmental friendly neutralisation method for the waste waters.

Key words: red heartwood, beech, steaming, colour homogenisation, waste water.

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