Water Absorption test by ASTM C272 calculates the relative absorption of water by different forms of sandwich construction core materials, when immersed in water or exposed to high relative humidity. The core materials include forms with continuous connecting areas (balsa and foam) and others with discontinuous connecting surfaces (honeycomb).
Water Absorption test of Core Materials by ASTM C272 is done by three different procedures: Test Method A for 24-hour immersion; Test Method B for Elevated Temperature Humidity; and Test Method C for Maximum Percent Weight Gain.
For the ASTM C272 test, the required number of test samples is five each with size 3.0 inch3.0 inch. Samples are first immersed in deionized water, then detached from the conditioning environment as per the required parameters (after 24 hours, 48 hours, or after thirty days). Then, the samples are placed in an oven for drying for a set time, and then subsequently placed in a desiccator for cooling. Finally, samples are measured to the nearest 0.1 mg using an analytical balance.
Three-inch by three-inch by 0.5-inch thickness core material samples are used for the Water Absorption test by ASTM C272.
The change in mass is calculated as follows:
Increase in Weight, % = (W – D) / D 100
W = wet weight
D = dry weight
Hence, water absorption by structured core materials can be determined by the standard method ASTM C272.