Influence of submersion time on fixation of copper-ethanolamine preservatives in wood

Baker-etanolaminski pripravki so najpomembnejša zaščitna sredstva za impregnacijo lesa v III. in IV. razredu izpostavitve po standardu SIST EN 335/1-2. Te pripravke pogosto uporabljajo tudi v podjetjih, ki nimajo na voljo impregnacijskih komor, zato les ščitijo s potapljanjem. Proučevali smo optimalen čas potapljanja, pri katerem dosežemo zadosten navzem, in pa vezavo baker-etanolaminskih pripravkov v les v odvisnosti od trajanja potapljanja. Smrekove vzorce različnih dimenzij smo za različna časovna obdobja namakali v komercialnem zaščitnem pripravku Silvanolin (Silvaprodukt) 2 različnih koncentracij (cCu = 0,25 ali 0,05 %). Ugotovili smo, da z daljšanjem časa namakanja narašča mokri navzem in globina prodora baker-etanolaminskih pripravkov v les, sočasno pa izboljšuje tudi kakovost vezave bakrovih učinkovin. Po 1 tednu namakanja smrekovine v zaščitni pripravek visoke koncentracije smo ugotovili, da so vzorci v povpreèju navzeli 275 kg/m3 zaščitnega pripravka. Bakrove učinkovine so prodrle 3 mm globoko. Izpirki iz impregniranih vzorcev, pridobljeni v skladu s standardom SIST ENV 1250-2 so vsebovali le 2,3 % bakrovih učinkovin.Copper-ethanolamine based wood preservatives are the most important products for protection of wood in use class III and IV applications according to EN 335/1-2 standard. These preservatives can be applied using different procedures. One of them is dipping, predominantly used method in less industrialised countries. The most important parameter influencing the quality of this treatment is dipping time. Influence of various dipping times on copper retention, adsorption, penetration, colour of the specimens and copper fixation was examined. Copper-ethanolamine solutions of 2 different concentrations were utilised (cCu = 0.05 or 0.25 %). The results showed that longer dipping treatments resulted in higher retentions, better penetrations and lower leaching out copper-ethanolamine based wood preservatives from Norway spruce wood. After 1 week of dipping, on average samples retained 275 kg/m3 of preservative solution, copper active ingredients penetrated 3 mm into the specimens, and only 2.3 % of copper was emitted from samples impregnated with aqueous solution of the higher concentration, according to ENV 1250-2 leaching procedure