Multi-scale computation of multistage manufacturing process signatures of glassy polymers multi-functionalisation

Abstract

To functionalize a glassy polymer surface like the Polycarbonate (PC) several process are needed: milling, turning, polishing and a chemical attack process. These processes sign the surface on a large band frequency from mm-wavelength for the milling, to the nm-wavelength for the polishing and the chemical attack process, passing through the µm-wavelength for turning. However, the band frequency available with a measurement is limited by the size of the measure and the step scale of the sampling. In this paper, a method to characterize the evolution of the surface has been developed with Wavelet Transform approach. Surfaces of each step were measured with an interferometer under different magnifications (x5, x50, x115). Their signatures calculated with Mexican hat wavelet transform were lengthened by continuity between the different magnification. Some conditions of the continuity are needed as having the same size and the same step scale on the measurement by adding interpolation points for the lower magnification. The results show clear correlation between the multistage process signatures and the function printability evolution like optical, design and mechanical.