The dynamic optimization of a heating process for plastic sheet production is modeled. The formulation is based on the representation of the one-directional heating process taking place in this system, and includes kinetic equations for the reaction of methylmethacrylate. The mathematical model is cast as a Partial Differential Equation (PDE) system, and the optimal profile calculation turns out to be a dynamic optimization problem with distributed parameter systems. A simultaneous approach was selected to solve the dynamic optimization problem. By the full discretization of all variables, a Non-Linear Programming (NLP) model is obtained and solved by using the CONOPT solver. We present results about the dynamic optimization of two plastic sheets of different thickness and compared them against simpler operating policies.