Laboratory Assessment of the Changes in Thermal Properties of Polar Diving Suit Material When Exposed to Oils at Low Temperatures

摘要

The U.S. Coast Guard is evaluating the use of divers under ice as one means of oil-spill surveillance in arctic and subarctic regions. The degree of thermal protection provided to the diver by presently approved suits, which are made of neoprene foam lined on one or both sides by nylon fabric, under the combined action of oil, water and frigid temperature is not known. The present report describes the results of a laboratory study in which any changes in the thermal and physical properties of the suit material were assessed through systematic tests on small samples (12 in x 12 in) when they were kept immersed in various oils and oil-water mixtures at various temperatures (-4 c to +10 c) and periods of time (5 to 22 hours). Physical (length, volume, density) and thermal (conductivity) properties of the samples were measured before and after each test. The results show that, although the suit material performs well in general, under certain conditions the fabric lining as well as the foam absorb some oil and that this absorbed oil cannot be removed easily either by physical expression or by cleaning with commonly available detergents. The absorbed oil leads to some increases in density and in thermal conductivity, with the latter change for the 'Worst case' being about 35%. (Author)