Scope:

The goal of this test method ASTM D2842 is to compare the relative water absorption tendencies of several cellular polymers. It’s designed for use in product specifications, evaluation, and quality control. It is only applicable to specific end-use design criteria if the end-use conditions are similar to the test method’s immersion period and 5.1-cm (2-in.) head requirements.

Procedure:

ASTM D2842 test method describes two procedures to measure the change in buoyant force:

Procedure A: In the immersion tank, an underwater weighing jig is placed. Specimens are immersed in an open-top immersion tank using a properly weighted rack. The water level is adjusted to keep a 5.1-cm (2-in.) head of water over the top of the specimens with horizontal sides of 15.2 by 15.2-cm (6 by 6-in.). The models are immersed for 96 hours. The test specimen is placed in the water and submerged. After the samples are removed from the water, the dimensions of the model are determined.

Procedure B: In the immersion tank, an underwater weighing jig is placed. The specimens that have to be tested by the ASTM D2842 method are immersed in the open-top immersion tank filled with freshly distilled water at 23 6 2°C (73.4 6 3.6°F) using an appropriately weighted rack. The balance on top of the tank is placed and then set to zero. The empty submerged jig is weighed to the nearest 0.1g. Without removing the test specimen from the water, it is placed in the submerged underwater weighing jig. The balance is maintained at zero by removing the plastic film from the water.

Data:

V1 = lwh

A = 2(l.w)+2(l.h)+2(w.h)

V2 = V1 – [A × (t/1.14)]

Result

For ASTM D2842, the average water absorption of the three specimens examined in volume percent is calculated. 

Conclusion:

The goal of this test method ASTM D2842 is to compare the relative water absorption tendencies of several cellular polymers.