A nondestructive method for quantifying the wood drying quality used to determine the intra and inter species variability
- INPL-UHP, Vandoeuvre-les-Nancy (France). Lab. d`Energetique et de Mecanique Theorique et Appliquee
- Ecole Nationale du Genie Rural, Nancy (France)
A nondestructive method for surface strain measurements is proposed to quantify the wood drying quality during convective drying. This method uses a visible laser scan micrometer intercepting needles maintained vertical at the board surface with a special device, and then gives shrinkage values at several surface points. The results analysis is related to heat and mass transfer phenomena. Experiments were made on softwoods and hardwoods either with superheated steam or with moist air. Results show that stages of shrinkage agree with classical periods of transfer. Besides, shrinkage results from a compromise between global shrinkage of the board section and local effects bound with drying conditions. The authors define two criteria for the drying quality. One compares experimental average shrinkage and free shrinkage, and the other quantifies the differences of shrinkage values between several surface points. Both criteria have to be associated in order to analyze the species behavior in terms of checking during the second drying period.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 516864
- Journal Information:
- Drying Technology, Vol. 15, Issue 5; Other Information: PBD: May 1997
- Country of Publication:
- United States
- Language:
- English
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