The permeation of gases through hollow silicone rubber fibers: Effect of fiber elasticity on gas permeability

The permeation of oxygen, nitrogen, argon, and synthetic air through hollow silicon rubber fibers was studied between 0° and 40°C and at gauge pressures of up to 3.45 × 105 N/m2 (50 lb/in.2 abs). The study was conducted in a permeator module in which the hollow fibers were pressurized externally. Strain measurements with single fibers showed this mode of operation to be preferable to internal pressurization. The gas permeation rates were markedly affected by dimensional changes of the hollow fibers under external pressure. These changes were predicted satisfactorily by a modification of Varga's (1966) deformation analysis of thick‐walled elastic tubes. The extent of air separation achieved in the permeator was in agreement with that calculated from theoretical models. It is conjectured that the performance of such a permeator may be improved in certain cases if the fibers are under suitable initial tension.