Poisson’s ratio of non-woven spun bonded fabric for medical apparel

An investigation of Poisson’s ratio of a series of spun bonded non-woven fabrics, differing in areal density, number of layers, testing directions and finishes, is reported. The Poisson’s ratio value is found to be higher with increase in the number of layers of spun bonded fabric assembly of fabrics of same Grams per Square Metre (GSM). The contraction in cross direction is higher than in the machine direction. Since spun bonded non-woven fabrics are anisotropic in nature, the Poisson’s ratio values range from 0 to 0.728 for the various extension levels that have been considered depending on the direction of action of the tensile force in the machine (MD) and cross directions (CD). The relationship between Young’s modulus & bending rigidity is poor. Flexural rigidity and Young’s modulus in machine direction are higher than in cross direction.