In this paper,25 mm thick poplar flooring blanks from Suqian,Jiangsu Province were chosen to compare the drying quality between the conventional drying and air-kiln combined drying.The results showed that the combined drying,which first lowered the moisture contention of poplar wood down to 25% by air drying and then shifted to kiln drying,could avoid drying defects such as end checks,collapse and warp with the same drying efficiency.

The Fraxinus mandshurica board was treated with superhigh temperature in atmospheric pressure superheated steam kiln and pressure steam tank respectively. The effects of two different treatments on the equilibrium moisture content (EMC),dimension stability,sorption hysteresis and shrinkage coefficient of the treated board were investigated. The reason for improving dimension stability by two treatment methods was further revealed. The results show that both of the two treatments can reduce the EMC of the wood,but the pressure steam treatment is more efficient than another one. That method has an advantage to reduce the change of wood moisture content due to the ambient relative humidity,reducing the shrinkage coefficient and increasing the dimension stability. An increase in the heat-treat temperature leads to a decrease of the sorption hysteresis of the heat-treated wood. The sorption hysteresis of atmospheric pressure super-heated steam kiln is lower than that of pressure steam tank under the same heat-treat temperature.

Taking 3.4mm warped Fraxinus Mandshurica wood veneer as the research object,the authors of this paper studied the effect of wet air treatment under different conditions(different air temperature,and different treatment time).The research result showed that:under the situation of 1℃of dry-wet bulb temperature difference,along with the treating temperature increasing from 70℃to 100℃and the treating time lasting from 1h to 3hs,the recover effect was strengthened.In consideration of the actual production situations,the authors suggest that the optimum technological parameters should be:90℃of temperature,1℃of dry-wet bulb temperature difference,and 2hs of processing time.