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Les kot organski material navadno sam po sebi ni dovolj odporen za uporabo na prostem, kjer je izpostavljen različnim dejavnikom razkroja. Zato ga je treba ustrezno zaščititi. Ena od rešitev je zaščita s hidrofobnimi pripravki, s katerimi poskušamo preprečiti dodatno navlaževanje lesa in ga s tem obvarovati pred glivnim razkrojem. Preučevali smo, kako učinkovito različni hidrofobni pripravki preprečujejo navlaževanje lesa. Iz smrekovine (Picea abies) smo pridobili vzorce, ki smo jih impregnirali z različnimi hidrofobnimi pripravki (rustikal olje, silikonska emulzija, laneno olje, montanski vosek, tungovo olje, itd.). Po impregnaciji in fiksaciji smo impregnirano stran vzorcev potopili v vodo. Navlaževanje vzorcev smo določili v skladu z modificiranim standardom EN 927-5. Vzorce smo potopili v vodo za točno določena časovna obdobja (1, 2, 3, 4 in 7 dni) in jim gravimetrično določili vlažnost. Nekateri hidrofobni pripravki dobro zaščitijo les pred vlago, drugi pa slabše. Med testiranimi hidrofobnimi pripravki se je najbolje obneslo rustikal olje, najslabše pa polietilenski vosek, ki smo ga pred testiranjem segrevali na 145 °C (WE1 50). Wood as organic material is generally not suitable for outdoor applications, as it is susceptible to different factors of decomposition. Thus, it has to be protected properly. One of the solutions is protection with hydrophobic solutions, which limits moisturizing, and therefore, protects it from fungal decomposition. The purpose of this research was to elucidate efficacy of different hydrophobic solutions, and emulsions to reduce or slow down moisturizing. Norway spruce (Pices abies) wood samples were impregnated with different hydrophobic solutions (rustical oil, silicone emulsion, linseed oil, mountain wax, tung oil, etc.). After the impregnation and conditioning, the impregnated part of the samples was exposed to water as prescribed by EN 927-5 standards. After respective periods of submersion, (1, 2, 3, 4 and 7 days) after uptake as gravimetrically determined. Hydrophobic solutions were more or less effective. Among the tested hydrophobic solutions rustical oil exhibited the highest efficacy, while the lowest hydrophobic effect was determined at spruce wood samples impregnated with polyethylene wax emulsions, which were heated above 45 °C prior testing (WE1 50).

Les, proizvod narave, material preteklosti, se je izkazal za nenadomestljivega. Njegova uporaba se iz dneva v dan povečuje. Sam les pa na žalost ni dovolj odporen, zato ga je treba predhodno zaščititi. Uporaba nebiocidnih pripravkov, kot so olja in voski z drugimi učinkovinami, je vse bolj pogosta. Da bi ugotovili, kakšna je njihova samostojna funkcija, smo na bukovini in smrekovini uporabili različna hidrofobna sredstva: laneno, tungovo in rustikal olje ter parafin in protektin. Polovico vzorcev smo izpostavili visoki relativni zračni vlažnosti, druge pa potopili v vodo. S spremljanjem mas in dimenzij smo dobili navzeme hidrofobnih pripravkov. Bukovina je bolj impregnabilna kot smrekovina, kar se odraža v večjem navzemu.V danih pogojih se je protektin kljub največjemu navzemu izkazal za najmanj učinkovitega. Med preizkušanjem, potapljanjem in kondiconiranjem v komori z visoko vlažnostjo, smo najnižje vlažnosti in s tem najboljše rezultate dosegli z vzorci, zaščitenimi s tungovim oljem pri obeh lesnih vrstah. Zaščita s tungovim, rustikal in lanenim oljem bolj učinkovito ščiti les pred navlaževanjem kot parafinska emulzija in protektin. Wood, as product of nature and so much used in the past, still proves to be irreplaceable. Its usage increases constantly from day to day. Unfortunately, it is not resistant enough. Therefore, it has to be protected, especially when used in outdoor conditions. The use of non-biocidal solutions, such as oils and waxes, is increasing. To research non-biocidal solutions used to protect wood without biocidal ingredients, beech and spruce wood specimens were protected with different hydrophobic preparations: linseed, tung, rustikal oils, paraffin and protektin wax emulsions. Some samples were exposed to very high relative humidity, others just immersed in water. During the experiment, the weight and dimensions were monitored. Beech wood was more impregnable than spruce wood, reflected in higher retention values. The highest retention was obtained with protektin. Nevertheless this solution exhibited the worst hydrophobicity. In both wood species, the tung oil proved to be the best. The results show that tung oil treated wood has the lowest humidity, regardless the method used. Tung, rustikal and linseed oil have better hydrophobic properties than paraffin emulsion and protektin.

V Tungovo ali kitajsko olje pridobivajo iz semen plodov tungovca, ki raste na kitajskem že stoletja. Olje ima izredno cenjene sušilne, polimerizacijske in odpornostne lastnosti zaradi visoke reaktivnosti sistema konjugiranih vezi a-eleostearinske maščobne kisline. Olje se na tržišču se nahaja v čisti, modificirani in polimerizirani obliki. Nanašanje olje je enostavno, filmi, ki jih tvori pa imajo odlične odpornost proti vlagi, acetonu, etanolu in alkalijam, zato lahko olje uporabljamo v najrazličnejše namene površinske obdelave ter zaščite lesa. Utrjeno olje je nestrupeno ter tako tudi primerno za uporabo na izdelkih, ki so v stiku s živili. Tung oil is obtained from the kernels of the fruit of the tung tree which has been grown in China for centuries. The oil has valuable drying and polymerization properties because of the high content of ?- eleostearic acid. There are three types of tung oil: pure tung oil modified tung oil and polymerized tung oil. Oil is easy to apply and the coating has superior resistances against water, alcohol, acid and weathering. Therefore it has found a lot of applications in wood protection. Dried oil is non toxic and therefore it is very suitable for protection of woody products which are coming in contact with food.