Increasing the Effectiveness of Water-Polymer Jet Cutting of Materials

Abstract A scientifically grounded hydrodynamic calculation method for determining the optimal parameters for cutting various materials using a water-polymer jet has been developed. The optimization of the cutting process parameters is invariant to the specific material being processed, as this method is based on an established criterion that incorporates the relaxation time of the polymer solution and the longitudinal velocity gradient occurring during the flow through the nozzle of the hydro-cutting head. An analytical expression for the relaxation time of the polymer solution has been derived, linking the experimentally observed relaxation time with the extrapolated relaxation time at zero concentration. The validity of this relationship, which connects the relaxation time of the polymer solution with its concentration, temperature, and intrinsic viscosity, is confirmed by experimental data on the concentration dependence of the relaxation time for two fractions of polyethylene oxide in water. The developed method for calculating the optimal parameters of materials cutting using a water-polymer jet enabled a significant reduction in the working pressure of the hydro-cutting machine – by 4 to 5 times – through the implementation of a high-efficiency cutting process. The experimental verification of the obtained results was carried out during the cutting of frozen pork. Under equal conditions, the cutting depth of frozen pork at -25°C was increased by 2 to 2.3 times compared to water jet cutting, whereas standard equipment achieved only a 1.85-fold increase. The experimental prototype of the hydro-cutting machine for materials using a water-polymer jet proved to be 10 times less expensive than industrial-grade equipment. The developed method for calculating the optimal parameters confirmed the practical feasibility and economic efficiency of using a water-polymer jet for cutting materials, particularly hard-to-process ones, by implementing a high-efficiency hydro-cutting process.