Ductility The ability of plastic to be stretched, pulled or rolled into shape without destroying its integrity. Typical ductile failure of plastics occurs when molecules slide along or past each other. Elasticity Elasticity is the ability of material to return to its original size and shape after being deformed. Elastic limit is the greatest stress which a material is capable of sustaining without any permanent strain remaining upon complete release of stress. It is expressed in force per unit area.
Most plastic materials have limited elasticity.
Friction and Wear Friction is resistance against change in the relative positions of two bodies touching one another. If the plastic in the area of contact is loaded beyond its strength, wear or abrasion will take place. Although plastics may not be as hard as metal, their resistance to abrasion and wear may still be excellent. Hardness Hardness is closely related to wear resistance, scratch resistance, strength, stiffness, and brittleness. An isotropic material is a material that retains the same physical properties when measured in any direction.