Process optimization for recovery of fiber backing from coated abrasive disks

Coated abrasive disks are supported by vulcanized fiber backing. The disks are normally used for various material removal processes, at the end of which the remaining backing is dumped as waste. Being vulcanized fiber, it is difficult to dispose of. It is non-biodegradable and causes environmental pollution. The fiber backing itself is costly and will be of value, if recovered. In this research work, chemical separation technique is opted to remove the available resin and grains from the fiber backing. The present work highlights and reduces pollution by addressing recovery of fiber backing from used fiber disks. Coated abrasive disks of grit sizes 36, 60, and 120 were chosen for the optimization process. The process parameters such as normality (2.5, 3, and 3.5 N), solution quantity (300, 400, and 500 ml), number of flexing cycles (0, 5, and 10), and immersion time (8, 10, and 12 h) were selected for the fiber recovery. Taguchi method was employed for the optimization process. Recovery duration was selected as a response parameter. Signal to noise (S/N) ratio was calculated from the experimental results, to optimize the quality and recovery duration of the fiber backing. The results indicate that increase in normality, solution quantity, and immersion time facilitate quick and easy recovery of the fiber backing. Apart from that, the disks of medium and fine grits are possible to reuse compared with coarser grit. The effectiveness of resin removal from the backing, is traced through optical microscopy.