Технологія і техніка друкарства (Nov 2022)
Applied Fourier Programming for metrological control of printing materials of packaging products
Abstract
In our manuscript, the materials of analytical substantiation and experimental verification of a new method of digital Fourier processing of polarization images of optically anisotropic polymer layers are presented. This method involves the following steps: ‘Fourier direct FFT’ — ‘Space-frequency filtering’ — ‘Inverse Fourier transform’ of laser images of a polymer material. The relevance of the topic is due to the need to search for new methods of Stokes polarimetry by using matched spatial-frequency filtering to diagnose and study the manifestations of various mechanisms of phase anisotropy of polycrystalline polymer networks for the creation and control of packaging printing products. The methods used in this work are aimed at studying the mechanisms for obtaining the coordinate distributions of the azimuth and ellipticity of the polarization of object fields of laser radiation, which are formed by various mechanisms of linear and circular birefringence of inhomogeneous polyethylene meshes in the boundary zone and the Fourier plane. To determine the main relationships between the optical-geometric characteristics of polymer networks and the distributions of azimuths and polarization ellipticity in the Fourier plane, computer simulation was carried out. Two types of objects were used as mock-up birefringent polymer meshes. The first type was a network of birefringent cylinders, which are located in the direction of the optical axes and are in the same plane. The second type is an ensemble of birefringent spheres whose centers lie in the same plane. We have proposed and analytically substantiated a unified model of a polymer layer, which is a superposition of linear and circular birefringence. The dependence of a set of statistical moments on the optical-geometric (geometric) parameters of virtual ordered cylinders and spheres is demonstrated.
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