Naslov
The efficiency of various treatments in ptotecting wood surfaces against weathering

Autori
Jirouš-Rajković, Vlatka ; Bogner, Andrija ; Despot, Radovan

Izvornik
Surface coatings international. Part B, Coatings transactions (1476-4865) 87 (2004), 1; 15-20

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
clear wood stain; photostabilisers; thin strip method; UV exposure; wood surface degradation

Sažetak
The depth profile of weathering effects on wood was studied after the laboratory ultraviolet exposure of fir-wood. The "thin strip" method (ie the measurement of changes in tensile properties of microtomed wood sections) was modified in terms of exposure of batches of strips packed in bundles and exposed in a QUV apparatus. The bundles of strips were exposed untreated, covered with surface strips that had been impregnated with chromium trioxide or Fe(III) nitrate, or protected with free films of clear stain with photostabilisers and without photostabilisers. It has been shown that ultraviolet (UV) light penetrates the wood surface to a depth greater than 70 m, resulting in changes in the tensile strength of the strips to a depth of 70 to 140 m. Strength changes in lower levels (down to 280 m from the surface) could not be clearly attributed to a predominant effect of UV light, and were probably controlled by hydrolytic processes. 100 hours of exposure enabled the effectiveness of several treatments to be established. The clear stain, enriched with a UV absorber and a HALS compound type, was shown to offer the best protection. Impregnation with aqueous solutions of chromium (VI) trioxide and Fe(III) nitrate proved ineffective in photostabilising the wood surface.

Izvorni jezik
Engleski

Znanstvena područja
Šumarstvo

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