Agro-Waste Based Friction Material for Automotive Application

The development of a non-asbestos automotive brake pad using palm kernel shell (PKS) as friction filler material is presented. This was with a view to exploiting the characteristics of PKS, which are otherwise largely deposited as waste from palm oil production, to make substitution for asbestos which has been found to be carcinogenic. Two sets of brake pads with identical ingredients but using either PKS or asbestos as base material were produced, following standard procedures employed by a commercial brake pad manufacturer. The physical, thermal, mechanical and the wear characteristics of the PKS-based brake pads were evaluated, compared with the values for the asbestos-based brake pads, and weighted against established recommendations for friction materials for road vehicle brake pads. The PKS based brake pad was characterized by 32.34 Brinell hardness number; 0.62%, swell and growth; 3375 N/s, bonding to back plate, and phase change at 689.5°C. The coefficient of friction of the experimental brake pad on cast iron was 0.43, while wear rate was 9.17 E-5 g/min and exhibiting a third order polynomial with run-in time. The properties of the PKS-based brake pad wholly satisfied the NIS 323 standard. The PKS is therefore suitable for use as friction material in automotive brake-pads. Current investigation is on field testing and reformulation of the composite for enhanced performance.