Ε½ .
Recently, a great improvement in the mechanical properties of drawn polypropylene PP has been achieved using a hot-die drawing Ε½ technique. In an attempt to describe the wear behavior of this polymer, wear tests have been carried out by rubbing a drawn PP Grade . GSE 108 pin against a rotating steel disc. The effect of drawing ratio on the friction and wear characteristics has been assessed and analyzed for various normal loads and sliding velocities. The results of this paper show that the wear loss values dramatically increase with an increase in normal load, draw ratio, and sliding velocity when the PP pin slides normal to the drawing direction. These values of wear loss decrease to about 50% when the pin slides parallel to the drawing direction. The use of grease lubricant reduces the wear loss to 10% of that achieved for dry motion. In addition, the average friction coefficient is greatly affected by the drawing ratio and the sliding Ε½ . velocity and direction. The highest friction coefficient m s 0.55 is observed when a drawn PP pin slides parallel to the drawing Ε½ . direction while the lowest value m s 0.42 is found when sliding at 67.58 with respect to the drawing direction.