Rheological Properties of Composite Materials for Manufacturing Sprayers of Agricultural Sprinklers

At present, the use of polymeric composite materials is becoming increasingly popular in various industries, including the application thereof in the agricultural sector. Polyoxymethylene (POM) has been chosen for the fabrication of the samples and is used in parts requiring for high rigidity, low friction, and excellent dimensional stability. This polymer is resistant with respect to impact loads, organic solvents, and oils and can be easily processed. Adding fillers in the form of fibers and particles to the POM polymer matrix provides improving POM performance characteristics, including physicomechanical properties. This paper presents the results of studies on the rheological properties of composite materials based on polyoxymethylene filled with fiberglass, silicon carbide, and graphite, obtained by means of mixing with the use of a HAAKE PolyLabRheomix 600 OS twin-rotor batch mixer. It has been found that, with increasing filler volume content to 20%, the viscosity of composites containing graphite and fiberglass exhibits a three- to fivefold increase as compared to the initial polymer. With increasing load, the value of the viscosity of the mixtures increases to an insignificant extent. For silicon carbide, the value of viscosity slightly varies depending on the amount of filler and on shear velocity. The highest viscosity is observed in the case of graphite, whereas the lowest is registered for silicon carbide, which may be connected with the size and shape of the particles. Resulting from the studies, it has been concluded that the most technologically appropriate material for the manufacture of agricultural sprinklers is a mixture of polyoxymethylene with silicon carbide, since it has the lowest viscosity.