The influence of conditioning on honeycomb development in high-temperature-dried Pacific Coast hemlock
1992
Dubois, J. | Avramidis, S. | Mackay, J.F.G. | Oliveira, L.
Three-foot-long specimens of 2- by 4-inch and 4- by 4-inch Pacific Coast hemlock lumber were conditioned immediately after high-temperature drying with the purpose of reducing degrade from honeycomb. Three runs with conditioning times of 2, 4, and 6 hours, and one control run (without conditioning) were carried out on both specimen sizes. Analysis of the results indicated that honeycomb was not significantly reduced by steam conditioning and was more likely to develop during storage at room temperature than during drying. No honeycomb was found immediately after drying in the 2 by 4 lumber stock. Honeycomb in the 4 by 4 lumber was associated with pieces of lumber with low initial moisture content (MC). At the end of the drying process, those 4 by 4's with low initial MC were found to be overdried below the targeted 12 percent MC and their final moisture gradients were also relatively steep, but were not significantly different than those developed by the nondefective 4 by 4's.
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