Development of a Composite-based Emery Polishing Sheet

A composite based Emery paper has been developed. The composite was developed from periwinkle shells grains, silicon dioxide and polyester resin. The composite sample grits were produced with 250 µm and 420 µm sieve sizes. The characterized periwinkle shell grains showed a weight composition of 92 % calcium oxide (CaO). A mechanical non-destructive test of hardness carried out showed that hardness of the composite grains increased with an increase of the binder’s weight composition as noticed in the 4 % and 12% polyester resin which yielded hardness of 9 Rockwell hardness value (HRB) and 12HRB respectively. The hardness of the finer grain of 250 µm sieved sized sample grit was found to be higher than that of the 420 µm sieve sized grains. The manufactured sample grits subjected to a polishing machine operation on 500 mm by 500 mm mild steel plate revealed that the 250 µm sieve size grains emery paper polished faster than the 420 µm sieve sized grain. The ANOVA result conducted showed that developed mathematical model for the polishing time of the 250 µm sieved sized emery paper usage was adequate for a p-value and R2 (adj) value of 0.0187 and 0.9671 respectively. A statistical probability plot showed that the residual points lay very close to the ideal diagonal distribution line which is clear evidence that the developed mathematical model is adequate without noticeable outliers in the model graphic.