Reticulated effectiveness assessment of polyurethane form in the melting process with deflagration method

The flexible polyurethane foam (FPUF) is widely used in the impact damping, noise insulation and other fields because of its good mechanical properties and porous structure. Unlike the previous methods, deflagration method can effectively remove partial original membrane while preserving skeleton structure, and is an environmentally friendly treatment process, representing an efficient and simple operation technology. Combustible premixed gas (CPG) is vital for deflagration process and can determine the reticulated effectiveness of polyurethane foam. The research purpose of this paper is to study the effect of the combustible premixed gas (CPG) parameters (the inflation coefficient, gas type and gas concentration) on the open porosity index of the polyurethane film through modeling and simulation methods. Based on the established mode, the paper uses the standard k-ε model coupling with the melting-solidification model based on the enthalpy-porosity method. The numerical simulation results demonstrate good agreement with the experimental data. The external surface center temperature (ESCT) is probably not constant but increases with the inflation coefficient. The analysis demonstrates that inflation coefficient significantly affects the concentration of CPG. Since the calorific value of combustible gas is limiting, a suitable union of inflation coefficient and concentration would provide better utilization of the method. Combustible gas with high calorific value were able to achieve an average open porosity promotion 0.275 within the inflation coefficient rage from 1 to 5. The approach adopted allows to provide heoretical basis for the efficient and standardized production of flexible polyurethane foam.