MATERIAL RESPONSE-BASED KILN CONTROL SYSTEM

The origin of material response (changing shrinkage rates) during drying is changing stress levels within the lumber as was determined in a previous paper. The object of this research was to demonstrate that a kiln control system based on material response parameters can reduce the drying time while incurring no additional drying defects. One control run and two pilot runs were performed. The results showed that it is possible to advance the kiln schedule using only material response as the controlling parameter and maintain or improve the quality of the lumber. Accelerating the drying substantially reduced the residual stress levels in the final product.