Question

Solve the following exercise using the infinity plate method under convection.
A large thermoplastic sheet, 10 mm thick, at an initial temperature of 20°C (293K), must be heated in an oven to mold it. The oven temperature is maintained at 100°C (373K), the maximum temperature to which the plastic can be subjected, and it is necessary to ensure that the temperature throughout the sheet reaches a minimum of 80°C (353 K) . Calculate the minimum time during which the foil should heat up. Thermal conductivity of plastic = 2.5 W/mK, Thermal diffusivity of the surrounding fluid =2x10^-7 m²/s, External heat transfer coefficient h =100 W/m²K

Answer 1