An Experimental Analysis of Stress Relaxation in Nonwoven Fabrics

The current research deals with an analysis of stress relaxation in nonwoven fabrics with different gsm values with a view to understand how these nonwovens behave under an applied stress for a given load over a constant period of time. An electronic stress relaxation tester is indigenously designed for this purpose which works on the strain gauge principle of measuring loads applied to the specimen at any given instant of time during the experiment. The respective stress values are calculated for corresponding load values for each specimen with every thirty seconds passage of time. The results obtained are graphically analyzed and it is revealed that the stress relaxation percentage is significantly different for the same nonwoven materials, but with different gsm values. It is observed that nonwovens do possess the property of decaying the stress generated due to external loads and the extent to which this happens depends to a considerable extent on the gsm of the structure along with other factors, like type of fiber and bonding.