Controlling of the Solvent Recycling Operation in the Washout of Photopolymer Printing Forms

Abstract

Printing production, like many other industries, is a source of waste that requires attention in terms of environmental impact. First of all, this applies to liquid waste as a result of the process of manufacturing flexographic photopolymer forms, because such solutions are mixtures of organic solvents that are hazardous toxic substances. Accordingly, developments in the direction of recycling such solutions will minimize their harmful effects on the environment and increase the technology’s energy efficiency through their reuse. Based on previous developments of a heterophase emulsion solvent and a washing device with the function of separation into fractions of a solution saturated with photopolymer by a ventilated separator, the principle of automatic control of the recycling operation using fuzzy logic is proposed. For such factors of the studied process in the form of linguistic variables as "Temperature of the leaching solution" and "Viscosity of the leaching solution" universal sets, corresponding terms are established and a fuzzy knowledge base is formed using the condition "If–Then". The output result is the linguistic variable "Quality of the leaching process". Using the Fuzzy Logic Toolbox system of the MATLAB technological calculation environment, membership functions were built, a knowledge base was formed, the diffusion operation was carried out using the "centre of gravity" method and a model of the influence of temperature and viscosity of the washing solution on the process of washout photopolymer printing plates was obtained. The model indicates the adequacy of the given knowledge base, which characterizes the process of leaching photopolymer forms. The numerical values obtained for processing by the fuzzy controller will determine the control action for the separator's automatic separation of the spent leachate.