ESTIMATION OF THERMAL-CONDUCTIVITY OF THERMOPLASTICS UNDER MOLDING CONDITIONS - AN APPARATUS AND AN INVERSE ALGORITHM

The thermal conductivity of thermoplastics is measured under moulding conditions (high pressure and high temperature). A specific apparatus has been designed and is described. A parameter estimation method is u sed for the experimental data processing. It is based on the resolutio n of a I-D non-linear inverse conduction problem. The optimisation alg orithm developed to solve the problem, is efficient and stable. confid ence intervals of the estimated parameters take into account errors bo th in the temperature measurements and in the parameters of the model. Heat capacity is estimated from calorimetric measurements, error anal ysis on the estimated conductivity is discussed, especially in the pha se change interval. Numerical validation and experimental examples are presented. (C) 1997 Elsevier Science Ltd.