Water absorption Test

The samples were immersed in 1.25m of water at 20˚C for 7 days to determine absorption through percentage variations in their flow thrust.

This test included samples which had been subjected to the two previous tests.

Conclusions

The 10 cycles of thermal stress described above have left no visible trace on the material, and its dimensions have shown no measurable variation.

The material is absolutely impermeable to water even after various immersions, and almost completely impermeable to the other liquids used in the tests. Thermal stress has had the effect of reducing its total liquid content, probably because of evaporation occurring during periods of high temperature.

General description of the test

Samples of the URETEK material were subjected to immersion in various liquids and to cycles of thermal stress. After the test, variations in volume were measured by means of a high precision optical measuring instrument, and the degree of liquid absorption through variations in flow thrust examined.

Temperature cycle

There were 10 cycles, each one consisting of the following:

• 08 hours in air at 65˚C
• 16 hours in air at 23˚C
• 08 hours in air at 30˚C
• 16 hours in air at 23˚C

Tests of immersion in liquids

The samples were completely immersed in various liquids at a temperature of 23˚C for 14 days. The liquids used were:

• Crude oil
• Fuel oil
• Gas oil
• High octane gasoline
• Kerosene

Two of the samples already subjected to thermal stress were also subjected to this test by immersion in high octane gasoline.