606 KB38 KB199820242017Čufar, KatarinaGorišek, ŽeljkoGornik Bučar, DominikaMerela, MaksStraže, AlešŠega, Bogdanštevilka:1letnik:66str. 17-26ISSN:0024-1067COBISSID_HOST:2793609URN:URN:NBN:SI:doc-ZZ0U7J91slBiotehniška fakulteta, Oddelek za lesarstvoLes (Ljubljana)air dryingbeechbukevdrying defectsFagus sylvaticakakovost lesakiln dryingkonvekcijsko komorsko sušenjelesnapake pri sušenjusušenje na prostemtimber qualitywoodVpliv sušilnega postopka na kakovost in izkoristek bukovega žaganega lesa| Impact of the drying process on the quality and utilization rate of sawn beechwood|We estimated the quality of beech (Fagus sylvatica) sawn timber before and after the industrial normal-temperature convection kiln drying and after air drying. We analysed 42 mm thick and 2.6 m to 5 m long boards, where we measured the number and size of end- and surface cracks, and fissures close to the knots. The orientation and direction of the wood grain, the number and size of knots as well as occurrence of red-heart and twisting were also determined. We ranked the boards using these criteria before and after the end of the drying processes in accordance with the standard of the European Organization of the Sawmill industry (EOS). We found a significant effect of drying on the occurrence of drying defects, but differences between the two procedures were not confirmed. The increase in the number and size of the surface and end cracks, especially in the boards assessed to lower B- and C-classes was obvious. The latter mainly contributed to the lowering of the quality of the sawn timber after drying from the A- to B- or lower class. After the kiln and air drying 20 % and 33 % of the sawn timber quality was degraded, respectively. The presented research was part of a larger study where we followed the quality of the beech timber from the forest to the final productOcenjevali smo kakovost bukovega žaganega lesa pred in po industrijskem normalno-temperaturnem konvekcijskem komorskem sušenju in po sušenju na prostem. Pri svežih žaganicah debeline 42 mm, dolžine 2,6 m do 5 m, smo izmerili dimenzije ter določili število in velikost čelnih in površinskih razpok ter poklin na grčah. Deskam smo določili še orientacijo in smer lesnih vlaken, število in velikost grč, prisotnost rdečega srca in veženja. S temi kriteriji smo deske razvrstili po kakovosti pred in po koncu sušenja v skladu s pravili Evropskega združenja žagarske industrije (EOS). Ugotovili smo značilen vpliv obeh sušilnih postopkov na pojav sušilnih napak, razlik med postopkoma nismo potrdili. Najbolj se je po sušenju povečalo število in velikost površinskih razpok, še posebej v nižjih B- in C-kakovostnih razredih, kot tudi čelne razpoke. Slednje so prispevale največ k nižanju kakovosti žaganic po sušenju iz A- v B- ali nižji kakovostni razred. Po tehničnem in naravnem sušenju smo 20 % in 33,3 % kakovost žaganic ocenili slabše. Prispevek je del raziskave sledenja kakovosti lesa bukve (Fagus sylvatica) od gozda do izdelkaTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaZveza lesarjev Slovenije