Drying behaviour of 1-inch tuai (Bischofia javanica Blume) in an electrically controlled lumber dry kiln
1993
Narendra Rasaily
The drying time with the use of the modified kiln schedule was longer by 24 percent than the standard drying schedule of FPRDI [Forest Products Research and Development Inst.]. This may be due to the low temperature and the high relative humidity at the initial stage. Another possible explanation for the prolonged drying time was the daily curtailment of electric current which may have disturbed the movement of water and prevented complete heating of the entire, cross section of the board to the desired temperature, particularly the core where the moisture content was the highest. The total drying time, using the standard drying schedule, was 185 hours and the modified drying schedule was 281 hours. It was found that specimens with higher final moisture content of 15% to 20% had better volume recovery upon reconditioning than those with lower final moisture content, which conforms with the findings of the CSIRO (1947). Quartersawn boards were generally found of better quality than plainsawn board but it was difficult to get pure quartersawn boards in Tuai owing to its spiral, waxy, and interlocked grains. Low temperature and high relative humidity reduced the risk of collapse to some extent but the drying time was considerably prolonged. The study proved that the drying of Tuai lumber is very difficult because it is highly prone to collapse, drying stresses, and warping
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