Study On Releasing Drying Stress Of Wood By MW Treatment

The paper mainly studies on how to release the drying stress of wood by MW treatment. Using Fraxinus mandshurica Rupr as raw material, effects of above elements on the wood drying properties, such as drying stress, moisture distribute field, drying rate are focused on in different drying stage. Thus the author put forward a kind of new method that use MW treatment instead of steaming process to release drying stress. In addition, the paper also makes comparison of two methods to measure drying stress. The results show that, 1. MW treatment cannot reduce the drying stress when moisture content is higher than FSP. Otherwise the moisture content gradient and drying stress can be reduced by MW treatment when moisture content is below FSP. 2. The results analyzed by SAS system show that moisture content has significant influence on drying stress. And output power of MW treatment has influence on drying stress, which can reach its minimum value at 480W. Time of MW treatment has little effect on drying stress. 3. MW treatment has effect on rate of drying. From the average drying rate, we can see that the rate become higher and higher with the increase of MW power. 4. The paper also makes comparison of two methods to measure drying stress. The results show that, the stress values, which are tested by two methods, are changed in company with MW treatment. But tendency of change is basically the same. There is a good linear correlation between section method and comb section method.