Grinding Process of Aramid Fiber Reinforced Rubber (3rd Report) —Analysis of Frictional Characteristics of Ground Surface—

Frictional characteristics of ground surface of aramid fiber reinforced rubber (AFRR), which is one of the advanced composite materials for transmission belt, are dominated by grinding conditions, and form and size of aramid fibers which aren't removed projecting on the surface of matrix rubber in grinding. In this paper, the coefficient of static friction is analytically described based on Hertz's theory of elastic contact in terms of arrangement of aramid fiber in matrix rubber, occupying ratio of fiber on contact surface of AFRR with pulley and so on, and the validity of this analysis is also discussed by comparing the theoretical coefficient with the measured one. It is pointed out that the coefficient of static friction on ground surface of AFRR can be predicted by fiber diameter, fiber content, length of projecting fiber, width of fiber end and coefficient of static friction of matrix rubber and aramid fiber. Though the coefficient of static friction on ground surface of AFRR is analyzed for four ideal conditions of projecting fiber, the measured coefficient agrees well with the analyzed one for the case that fibers are uniformly arranged in hexagonal form and ground in the direction of a central diagonal of this hexagonal fiber arrangement. Furthermore, the validity of this analysis is shown by investigating effects of pressure on contact conditions between pulley and ground surface of AFRR.