Effect of Alcohol in Preventing Collapse Under Extreme Drying Conditions

Extreme checking and collapse in red oak (Quercus rubra L. and yellow birch (Betula alleghaniensis Britt.) under oven-drying conditions can be eliminated if the water in the specimens is replaced prior to drying by a solution having a lower surface tension. Test specimens were prepared from red oak and yellow birch heartwood. These were 4 inches long and divided into two series according to cross-section dimensions. One series was 3/4-inch square and the second series was l-inch wide in the tangential direction and 1/4-inch thick in the radial direction. The average moisture content was determined for each group and the volume of moisture per specimen in each group was calculated. Specimens were weighed to 0.01 gram and measured to 0.001 inch. Using a vacuum technique, water was replaced by either ethyl alcohol or n-propyl alcohol of varying concentration so that the calculated final concentration of alcohol in the wood was 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, and 100 percent. The specimens were then ovendried to constant weight at 105?C. and the dimensions were measured. This was followed by steaming for 24 hours to remove residual alcohol. Then the specimens were redried in an oven at 105?C. and remeasured.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member