Abstract:

The stress of surface layer of small-diameter Asian White Birch(Betula platyphylla)timber with consecution-heat and intermittent-heating(intermittent 2 h and intermittent 6 h)was discussed.The results showed that the change of tress of surface layer with three kinds of heating methods were in a similar way.However,during either prophase drying or metaphase drying,the stress with intermittent-heating was smaller than that with consecution-heat,the stress was least with intermittent 6 h.The drying stress was loosed during intermittent,intermittent time more long,the effect of loosen more remarkable.At the same moisture content level,the stress of surface layer of tangential timber was larger than that of radial timber.

Key words: small-diameter Asian White Birch, timber, surface layer stress, heating methods