EFFECT OF DIFFERENT FREEZING CONDITIONS UPON THE DIFFUSION COEFFICIENT OF SPRUCE WOOD

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关键词: moisture diffusion;    spruce wood;    frozen wood;   

DOI  :  

来源: DOAJ

【 摘 要 】

The paper presents a study concerning themodifications induced by different freezingconditions upon the moisture diffusion in spruce(Picea abies L.) wood.The diffusion coefficients in radial andtangential directions were determined at 20°C/35%and 40°C/35%, on wood samples initially subjectedto rapid freezing (at -10°C/h freezing rate),respectively slow freezing (at -1°C/h freezing rate),then maintained for 1 week in frozen condition,comparatively to samples originating from the samelog but stored in an open yard for three wintermonths (December-February) and also compared tonon-frozen samples. All samples were subjected tothe diffusion test after being dried - to 12% mc.These testing conditions were chosen so as toevaluate the influence of the freezing speed (rapidvs. slow freezing) and of the exposure duration tofreezing conditions (1 week vs. 3 months) upon themoisture diffusion in spruce wood – which is animportant property related to the dynamics of wooddrying.The results show that rapid freezing at -25°Cdo not affect moisture diffusion, while slow freezing(at a freezing rate of -1°C/h) and long-termexposure to negative temperatures increasemoisture diffusion by 15-33% compared to unfrozenwood. The higher values were recorded intangential direction and with the higher testtemperature (40°C).

【 授权许可】

Unknown