1. Strength:
Cloth should possess a high resistance to the continuation of a tear already started, whereas breaking strength always applies to the simultaneous breaking of system of yarns.
2. Tear Resistance:
It is the resistance principally of one yarn at a time to a rupture travelling crosswise from yarn to yarn. In construction of a parachute the gores or panels are usually cut on the bias, so that the warp and filling yarns make an angle with the seams running from the centre to the hem of the parachute. In this way, if tear is started, it follows along the direction of a yarn to the seam where the resistance is sufficient to prevent further rupture.
3. Elasticity:
Parachute’s quick and positive opening, depends largely on the ability of the layers of the cloth to spring apart along the folds, thus permitting air to rush in and quickly inflate the envelope. The elasticity of cloth tends to distribute the sudden load more uniformly over the envelope, thereby preventing development of excessive stress in the region of the envelope.
4. Permeability:
Permeability is dependent upon the porosity of the fabric. The porosity is largely determined by the tightness of the fabric weave. Therefore any fabric that has reasonably tight weave is suitable for this perspective.