Optimization of values of technological parameters for obtaining thermoplastic polymer composition for bottom shoes

This work reveals the dependence of the composition and production parameters on the properties of a thermoplastic polymer composition based on a copolymer of ethylene with vinyl acetate and suspension polyvinyl chloride (EVA / PVC-S), as well as the choice of the optimal composition of the mixture and finding the optimal technological parameters for its production. Thermoplastic polymer-sole compositions were obtained by the method of thermomechanical mixing. To describe the properties of polymer - plantar compositions, depending on the ratio of components and technological parameters of obtaining, the method of mathematical planning – “Full factorial experiment” of type № = 2k was chosen, which allows to obtain separate estimates of linear effects and two-, three-factor interactions. In this work, to build a mathematical model, the following factors were selected: the content of EVA in the composition, the temperature and mixing rate, and regression equations were used when obtaining a new type of shoe bottom material using a full factorial experimental method. Optimal results were obtained when the EVA content of the polymer composition was 15%, the mixing temperature was 185°C, and the mixing speed was 25 rpm. The strength and operational-technological indicators of the quality of a thermoplastic polymer composition for the bottom of footwear based on a copolymer of ethylene with vinyl acetate and suspension polyvinyl chloride have been determined. Regression equations for the dependence of the deformation-strength properties on the technological factors of the creation of polymer sole compositions are constructed. It has been proved that by selecting the optimal values of technological parameters it is possible to obtain a sole material with high deformation-strength and operational-technological characteristics.