Air Permeability of Composite Fiber Material

Abstract

The air permeability of composite materials obtained by impregnating a nonwoven needle-punched fabric with latex has been investigated. The permeability of composite materials with different rubber content was estimated by the coefficient of air permeability at a pressure drop of 49 and 100 Pa. It is shown that, with a degree of impregnation of 15–20 wt %, the maximum air permeability coefficient is observed, and with an increase in the degree of impregnation, the air permeability coefficient decreases. The process of formation of the porous structure of composite materials and its effect on air transport are considered. An increase in the air permeability coefficient is probably associated with the fixation of the fibers of the surface layer and the limitation of their mobility under the action of an air flow, and a decrease in the air permeability coefficient is associated with a decrease in the pore space and an increase in the volume of the fibrous matrix of composite materials during the drying of the impregnated material. The air permeability of composite materials is determined by the ratio between the processes of increasing the volume of the fibrous matrix and decreasing the porosity when filling the space between the fibers with rubber particles. A model is proposed for calculating the coefficient of air permeability of composite materials of known density.