Jute fibers and powderized hazelnut shells as natural fillers in non-asbestos organic non-metallic friction composites

The paper addresses the potential application of jute fibers in combination with powderized hazelnut shells as natural and biodegradable fillers in non-asbestos organic (NAO) friction composites. Two groups of the samples, based on a combination of jute fibers and graphite as a solid lubricant, and the jute containing samples where graphite is replaced with hazelnut shells, were prepared. Friction-wear properties of the prepared samples were evaluated using the CHASE tester according to the SAE J661 recommendation. The friction-wear tests revealed the jute with graphite samples to show significant fade phenomenon if the temperature during the second fade test increases above 300 degrees C. The samples belonging to the jute with hazelnut shells group show better resistance against the fade phenomenon even at temperatures higher than 300 degrees C. Based on the comparison of the overall friction performance, the composite with 5.6 vol.% of jute fibers and 8.4 vol.% of powderized hazelnut shells (assigned as JH-5.6) was selected as the best performing, and this composite contains 14 vol.% of natural, renewable and biodegradable components. If we accept that the maximum temperature during braking will be up to 290 degrees C then the composite with 23.6 vol.% of jute fibers and 6.3 vol.% of powderized hazelnut shells (assigned as JH-23.6) shows an acceptable stability of the friction coefficient, whereas this composite contains almost 30 vol.% of natural, renewable and biodegradable components. (c) 2013 Elsevier Ltd. All rights reserved.