Experiments on An Accelerated Method for Determining Water-Absorption of Hardboard

The experiment used two adjacent sample strips 6 inches by 4 feet cut from a 4 foot by 16 foot panel. Each sample strip was cut into six test specimens. Seventy-three boards were sampled for a total of 870 test specimens. The test specimens from one strip were soaked as a unit. Each specimen was weighed to 1/10 gram and measured to 1/1000 inch in thickness and 1/100 inch in width and length. The specimens for the 24-hour absorption test were stickered and conditioned at 50 percent R.H. and 70?F. The specimens for the pressure absorption test were stickered and allowed to cool for 20 minutes. The equipment for testing includes a pressure tank in a constant temperature bath (20?C.) which also serves as the soak bath for 24-hour absorption. In conducting a pressure soak, the pressure tank is filled with water. The five test specimens are stickered by means of brass wire spirals and immersed in the tank, the cover placed on the tank and bolted down. The blowdown valve is closed and the air inlet opened. At the end of 30 minutes at 5 psi the air inlet valve is closed and the blowdown valve is closed and the blowdown valve is opened. The cover is removed and after removing the samples, the excess water is removed with a cloth. The specimens are weighed and the percent absorption, specific gravity volume calculated respectively. In both pressure soak and 24-hour soak, the relationship of water absorption and specific gravity of specimens is linear, the water absorption decreased with increased specific gravity. Based on the correlation curve of specific gravity and absorption, it is possible to predict the 24-hour absorption. Prediction of the 24-hour absorption results in errors of 2.0 percent or less in 95 percent of the predictions.

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