Tribological and thermo-mechanical properties of glass- and basalt-fibre-reinforced HDPE/PA6 composites for idler roller applications

Conveyor belt idler rollers are vital for supporting and guiding conveyor belts, ensuring safe and efficient operations. In recent years, polymeric materials such as high-density polyethylene (HDPE) and polyamide 6 (PA6) have emerged as alternatives to steel in the fabrication of idler rollers, due to their lightweight and corrosion-resistant properties. However, their susceptibility to abrasion and fatigue limits their performance under high loads. This study was aimed at enhancing the thermo-mechanical and tribological properties of HDPE/PA6 and recycled HDPE/PA6 blends for idler roller body fabrication, compared to a reference industry formulation. Blends containing 80 wt% HDPE or re-HDPE and 20 wt% PA6 were melt-blended with 2 wt% polyethylene grafted with maleic anhydride (PE-g-MAH) as a compatibilizer. The addition of 15 wt% glass fibres (GF) to the compatibilized HDPE blend resulted in a 9 % increase in the heat deflection temperature (HDT), and reductions of 42 % and 29 % in the wear rate and coefficient of friction (COF), respectively, compared to the industry reference material. A similar trend was observed in the HDT, wear rate and COF of the 80 wt% re-HDPE blend, with the reduction in the wear rate more pronounced. Finite element simulations using Abaqus confirmed that the 7-inch outer diameter idler roller prototype made from 15 wt% GF reinforced 80 wt% HDPE blend had a lower maximum deflection of 0.054 mm, compared to that of the industry reference material (0.059 mm) under a 4889 N load, demonstrating improved structural rigidity. These results indicate that re-HDPE/PA6-GF composites offer a durable, lightweight, and corrosion-resistant alternative to conventional metallic rollers, with potential for extended service life and energy-efficient operation in bulk material handling systems.