Water repellent efficiency of wood treated with copper-azole combined with silicone and paraffin emulsions

Abstract

Copper-azole free of chromium and arsenic is one of the potential wood preservatives against wood decay organisms being on the market as an alternative to CCA (copper, chrome, arsenic). In this study, copper-azole solution with the concentration of 2.4 % was mixed with water repellents, 0.5 %, 1 % and 2 % of silicon emulsions as well as 5, 10 and 15% of paraffin emulsions respectively. In the first experiment Scots pine samples were treated with these solutions followed by a fixation step in a conditioned chamber (21°C , 65% RH). In the second experiment, treatment of the Scots pine specimens was done with the same formulations, but the samples were dried in an oven at 100 °C for two days in order to measure water absorption and water repellency efficiency. Paraffin emulsions reduced the water absorption more than copper-azole alone and silicon based formulations when the samples left the fixation in the conditioning chamber. Water absorption increased in the samples dried at 100 °C compared to those left to ambient condition. The oven drying increased the water absorption to the copper-azole treated wood. Paraffin emulsions lead to better water repellency compared to control and silicon emulsions, but the increasing in the paraffin emulsion did not improved the efficiency.