ASTM E96 Water Vapor Transmission Scope:

ASTM E96 test determines water vapor transmission (WVT) through materials such as paper, fiberboards, gypsum, plastic films, sheet materials, plaster products, wood products, and plastics. The designers and manufacturers in the industries might consider this data for packaging material application. The Desiccant Method and the Water Method are the two methods for measuring permeance. The service conditions have two variations with one side wetted (low humidity on one side) and high humidity on the other side. ASTM E96 test is used for measuring the transfer of water vapor via semi-permeable and permeable samples. 

Test Procedure:

For the ASTM E96 test, a cup is filled with distilled water. It is filled in such a way that air space between the sample and the water leaves a small gap of (0.75 inches to 0.25 inches). Then, the cup is wrapped to avoid vapor loss from anywhere but the test sample. The initial weight of this whole assembly is taken and regularly weighed until the results become linear. It must be carefully assured that all weight loss is because of water vapor transmission through the sample.

Sample size:

44-inch sample

Data:

A weight versus time or a percent transmission versus time graph is plotted.

Conclusion:

ASTM E96  test method is specifically important for the water transmission test of packaging materials to suggest improvements in their production. The results aid in enhancing their quality keeping in view the global standards.