ASTM D570 Water Absorption of Plastics

ASTM D570 Water Absorption of Plastics Scope:

In the ASTM D570 method, plastics’ relative water absorption rate when immersed is determined. This test method is suitable for all sorts of plastics, including cast, hot-molded, and cold-molded resinous products and homogeneous and laminated plastics. This rate of water absorption test method serves two purposes: first, as a guide to the proportion of water absorbed by a material, and second, as a control test on the uniformity of a product. The second function is particularly useful for sheet, rod, and tube arms when the test is performed on the finished product.

Procedure:

This method, ASTM D570, first involves the twenty-four-hour immersion in which the conditioned specimen is placed in a container filled with distilled water, and its temperature should be maintained at 23 6 1°C (73.4 6 1.8°F). After a 2-hour immersion, a specimen may be weighed to the nearest 0.001 g, then returned to the water and weighed again after 24 hours. Then specimens are placed in a container of boiling distilled water for different hours. In the end, data is compared with the absorption values of other plastics.

Data:

In the ASTM D570 test method, the percentage increase in weight can be calculated as follows:
Increase in weight, % = wet weight ­ conditioned weight/conditioned weight × 100
The percentage of matter lost during immersion can be calculated as follows:
Soluble matter lost= conditioned weight ­ reconditioned weight/conditioned weight × 100