ИССЛЕДОВАНИЕ ФИЗИКО-МЕХАНИЧЕСКИХ СВОЙСТВ ПОЛИУРЕТАНОВЫХ КОМПАУНДОВ ДЛЯ ОЦЕНКИ ВОЗМОЖНОСТИ ИХ ПРИМЕНЕНИЯ В МЕМБРАННО-ПОРШНЕВОМ НАСОСЕ

Abstract

The diaphragms in diaphragm piston pumps serve as the main working parts, the failure of which entails the shutdown of the entire pump, and, as a result, the sprayer, which leads to a decrease in the efficiency of agricultural activities and an increase in the cost of restoring the operability of agricultural equipment. The relevance of using the technology of free casting of twocomponent polyurethane in silicone molds in the organization of repair sites is due to the high quality of the parts obtained with a significant reduction in cost, as well as production time. Since the main reason for the failure of the membrane is abrasive wear and cyclic loads, the determining properties are hardness, strength and ductility of the materials used. (Research purpose) The research purpose is assessing the hardness, strength and plasticity of polyurethane compounds of various brands, depending on the production conditions of the sample, and concluding their applicability to manufacture piston pump diaphragms by free casting. (Materials and methods) Presented studies of hardness, tensile strength and elongation at break of three grades of polyurethane compounds PolyFlex 80A, Advaform Mark 80 and Silagerm 6080, depending on the technological modes of manufacturing samples from them. (Results and discussion) It was found that the curing of polyurethane compounds at higher temperatures allows for high strength and plastic properties of the material. It was noted that during curing, molecules are redistributed into the most favorable energy configurations, which exclude the appearance of structural stress concentrators, increasing the plasticity and strength of the material. The increased temperature helps to remove residual stresses in the material that occur during shrinkage. (Conclusions) The application scope of the research results is the manufacture of polymer parts of agricultural machinery, in particular, diaphragm diaphragm piston pump.