Creep and wear behaviour of ethylene-butene copolymers reinforced by ultra-high molecular weight polyethylene fibres

Filament wound flat strips of polyethylene-butene copolymers (PE) reinforced by continuous fibres of ultra-high molecular weight polyethylene (UHMWPE) were tested in a ball-on-prism tribometer against steel balls. The winding angle (τ = 35 and 50°) and the branching ratio (flexibility) of the matrix polymer were varied. The static penetration of the ball into the sample material (creep), the running-in wear and the steady-state wear were measured. The creep resistance of the neat matrices decreased significantly with increasing branching of the copolymer. All fibre reinforced versions had almost the same creep resistance as the stiffest matrix polymer. The running-in wear was governed by the peeling-off of a thin matrix layer which happened rather fast. During the steady-state phase, the wear was controlled by the wear resistance of the fibres. All composites revealed the same wear rate. Strong fibrillation of the composites was observed.