| In this study the influence of processing parameters namely sheet temperature, plug temperature, and plug material on wall thickness distribution in plug-assist pressure thermoformed polypropylene cups is presented. Experimentation was performed at sheet temperatures of 156°C, 160°C, and 164°C, plug temperatures of 30°C, 45°C and 60°C, and plug materials used were thermoplastic syntactic foam, thermoplastic non-syntactic and epoxy syntactic. The thermoforming process was simulated using T-SIM®, and coefficient of friction values between the sheet and plug were optimized to get good match between the simulated and experimental results. It was observed that with the increase in sheet temperature wall thickness and the bottom corner thickness increased while the bottom thickness increased. With the increase in plug temperature, the bottom thickness increased and the bottom corner thickness decreased. Plug material had a significant effect on the bottom corner average. Good correlation between the simulation and experimental results was obtained at a sheet temperature of 160°C, while the simulation result did not match the experimental results at sheet temperatures of 156°C and 164°C. |
