Buoyancy Material for Underwater Robots Exported to the Middle East

The buoyancy material should be selected accounting for the water depth to which it is exposed, exposure to chemicals and extreme temperatures and the extent of loads encountered during service life of the system.

The objective of underwater vehicle flotation systems is to counteract the negative buoyancy effect of heavier than water materials on the submersible (frame, pressure housings, etc.) with lighter than water materials (i.e., buoyancy material with specific gravity less than that of the ambient water conditions). A near neutrally buoyant state is the goal. The flotation material should maintain its form and resistance to water pressure at the anticipated operating depth. The most common underwater vehicle flotation materials encompass two broad categories: rigid, lightweight materials such as polyurethane or polyvinyl chloride (PVC) foams, for shallower depths, and syntactic foams that can support full ocean depth systems. For the deepest trenches, innovative techniques for buoyancy such as ceramic spheres have also been used.

When glass microspheres are used within the resin—some call them balloons while others call them bubbles—and the disbursement is controlled so the optimum packing factor is attained, then syntactic foam is created. This is referred to as “solid syntactic.” Solid syntactics range in density from 13 lb/ft3 (0.2 g/cc) to 42 lb/ft3 (0.67 g/cc.) depending upon the service depth requirements.

GURIG SBM is a composite lightweight buoyancy material. This material is mainly formed by using epoxy resin as a binder and filled with a large amount of hollow glass beads and other additives.