Effect of cutting parameters on surface roughness in ultra-high precision turning of a contact lens polymer

This paper studies the effect of cutting parameters on surface generation in ultra-precision turning of a contact lens polymer. Contact lens manufacture wants high accuracy and high surface quality. Surface roughness is mostly used to measure the index quality of a turning process. It has been an important response because it has direct influence toward the part performance and the production cost. Hence, choosing optimal cutting parameters will not only improve the quality measure but also the productivity. This research work is therefore aimed at investigating the effect of cutting parameters (cutting speed, feed rate and depth of cut) on surface roughness of RGP ONSI-56 contact lens polymer with a monocrystalline diamond cutting tool. In this work, cutting speed (A) is found to be the most dominant factor having the highest degree of significance followed by the square of the cutting speed (A2) and the feed rate (B). However, interaction between cutting speed and feed rate (AB) has the lowest degree of significance on the surface roughness.