The kinetics of adsorption of pure polydimethylsiloxane or of bimodal mixtures, onto silica aggregates, was observed from the melt as a function both of polymer weight fraction (2.5 to 20 g/g) and of the specific area (50, 150 and 300 m(2)/g). Attention was focused on filled polymers wherein silica aggregates are connected to one another by adsorbed chains to form a network. Results were analysed according to a molecular approach. All observed kinetics curves were found to obey a property of superposition by using a suitable reduced time variable defined as : (n)/Qi; <(M-n)over bar>, is the number average molecular weight and Q(i) is the initial amount of polymer per unit mass of silica. The rate of adsorption is proportional to 1/Q(i).