Comportamiento en Desgaste por Abrasión de Dos Cuerpos de Polietileno Ultraorientado

MAXIMILIANO JALIF; W. R. TUCKART; C, ROSSIT; M. FAILLA

Santa Fé

Congreso; Congreso Iberoamericano en Ciencia y; 2014

Asociación Argentina de Materiales

Monofilament and fibers of high density polyethylene(PE) are characterized by having the main axis of the molecular chains highly oriented along the length of the filament that provideshigh elastic modulus and strength. Numerous studies have been conducted to establish the relationship between degree of orientation andmechanical properties of these materials, however little is known about its tribological response. In this work, the abrasive wearbehavior of monofilament of polyethylene obtained with different degrees of molecular orientation was studied. A high density PE wasdeformed from the solid state to obtain filaments with morphologies with varying degrees of molecular orientation. The filaments were obtained by extrusion of cylindrical samples through capillarynozzles with different diameters to provide orientation ratio (RND) from 2 to 16. RNDvalue determines the degree of molecular orientation in the filaments. Thus, the larger the RND value, the greater the degree of molecular orientation. The abrasive wear rate of the filaments was evaluated by pin-on-drum test. As abrasive a SiC emery cloth (grade 320) was used, which was adhered to the drum. The sliding distance was 2.4 m inone pass condition. Different normal loads were applied to the filaments, due to the differences between their diameters, so as to give the same contact pressure in each test. The wear rate was obtained by measuring the mass loss of the material. The results indicate that the wear rate decreases monotonically with RND. Thus, as example, the material with RND of16 shows a wear rate eight times lower than that of  the material with RND of 2.