Impregnability and leachability of copper based preservatives with regard to anatomical plane of wood

Zaradi omejitev uporabe klasičnih baker/kromovih pripravkov, industrija išče alternative za zaščito lesa v stiku z zemljo. Za impregnacijo takšnega lesa moramo uporabiti fungicide, ki se iz lesa ne izpirajo. Učinkovitost vezave v les določamo s standardno metodo, z majhnimi vzorci, kjer je delež aksialnih površin večji kot v praksi. Namen prispevka je ugotoviti, kakšno je izpiranje bakrovih učinkovin iz različnih anatomskih smeri. V ta namen smo orientirane smrekove vzorce impregnirali s pomočjo vakuuma z dvema bakrovima pripravkomavodno raztopino bakrovega(II) sulfata in komercialnim pripravkom Silvanolin. Rezultati so pokazali, da je izpiranje iz radialnih in tangencialnih površin primerljivo. Ugotovili smo, da se modra galica pri višjih koncentracijah najbolj izpira iz aksialnih ploskev, Silvanolin pa iz radialnih in tangencialnih površin.Due to the limited use of classical copper/chromium based preservatives, the industry seeks for alternatives for preservation of wood in ground applications. For such purposes, fungicides fixed in wood are utilised. For estimation of fixation, standard method that prescribes small specimens with higher portion of axial surfaces than in practice is utilised. The purpose of this article is to determine copper leaching from different anatomical planes.Orientated Norway spruce wood blocks were impregnated with aqueous solution of copper(II) sulphate and commercial preservative Silvanolin. The results showed comparable leaching from radial and tangential surfaces. However, more prominent leaching of copper(II) sulphate at higher concentrations and less extensive leaching of Silvanolin from axial surfaces was established

Comparison of standard procedures for estimation of biocides leaching from impregnated wood

Izpiranje aktivnih učinkovin iz impregniranega lesa je eden izmed najpomembnejših kriterijev za presojanje uporabnosti zaščitnih pripravkov za zaščito lesa na prostem. V te namene uporabljamo več različnih standardnih in nestandardnih postopkov: SIST EN 84, SIST EN V 1250-2 in priporočilo OEC D. V sklopu te raziskave smo med seboj primerjali izpiranje bakrovih in borovih spojin iz lesa, zaščitenega s pripravki: (a) vodno raztopino bakrovega sulfata, (b) bakeretanolaminskim komercialnim pripravkom Silvanolin, (c) vodno raztopino borove kisline in (d) kombinacijo borove kisline in vodne emulzije voska montana. Globinsko impregnirane vzorce smo izpirali in določili delež izpranega Cu in B. Največji delež biocidov smo izprali iz lesa zmetodo SIST EN 84, najmanj pa z metodo OEC D. Kakorkoli, z vsemi testiranimi metodami smo prišli do istega vrstnega reda pripravkov glede na delež izpranih aktivnih učinkovin iz lesa.Leaching of active ingredients from impregnated wood is one of the most frequently applied criteria for assessing the suitability of impregnated wood to be used in outdoor applications. For this purposes, several standard and nonstandard procedures are applied. Within the framework of this research, leaching of copper and boron compounds from wood, impregnated with four different wood preservatives, were compared: (a) aqueous solution of copper sulphate, (b) commercial copper-ethanolamine based solution Silvanolin, (c) aqueous solution of boric acid and, (d) combination of boric acid and montanic wax emulsion. Pressure impregnated specimens were afterwards leached according to the three different standards: SIST EN 84, SIST EN 1250 and OECD recommendation. The highest portion of leached biocides were determined according to the SIST EN 84 procedure, the lowest portion according to OECD recommendation. All three methods applied, however give us the same ranking of wood preservatives regarding the amount of emitted active ingredients