Geometrical shape improvement of steel moulds by robot polishing process for polymer optic replication

Abstract

The quality of injection-moulded polymer optic parts depends on the surface finish of the respective mould. In order to improve the surface finish of the mould, it is important to use a tactical material removal, which allows a controlled correction of the mould's surface geometry. The aim of this work is to use a polishing correction technique to improve and correct the flatness of hardened steel samples in order to reduce the need for manual polishing. A polishing tool function is simulated from the contact between the tool and the hardened steel sample and used to determine the material removal rate per time. A feed profile is calculated, which allows the industrial robot to tactically control the material removal. It is observed that a correction improves the surface's flatness by up to 70%. ARTICLE HISTORY

Steel mould surface improvement by robot fluid jet polishing and robot pad polishing for polymer optic production

“…It was possible to improve the surface quality of steel samples in terms of surface roughness and shape deviation. It was possible to reduce the working/polishing time compared to previous works [8]. Considering the shape deviation, the error of the sample was 963,7 nm in the beginning.…”

“…In order to decrease the production time of the final part in the plastic injection moulding process, the steel moulds geometrical shape also needs to be optimized. In previous works [8], it was possible to correct the geometrical shape of flat hardened steel samples from 668.8 nm to 214.2 nm by using the robot pad polishing process. This represents an improvement of 68%.…”