Cost-effective open microwave heating of polymer resin using interdigital electrode array film and dispersed carbon nanotubes

Conventional microwave heating requires an expensive facility and its enclosed-type oven limits the size of curable products. This article proposes an open-type microwave heating of a polymer resin using microwaves produced by an interdigital electrode array film positioned between the composites and the mold. The proposed method has the advantages of reduced facility cost and applicability to large composite structures. The dispersion of carbon nanotubes (CNTs) in the resin also enables the use of a relatively low applied voltage for the heating. This is because the CNT-filled resin has a high dielectric loss tangent. The generated heat was observed to increase with the CNT content and a heating efficiency of 70% was achieved. It was particularly observed that a significant temperature increase occurred at 0.08 wt% CNT content owing to the electric percolation phenomenon. Moreover, selective microwave heating using an electrode array also enabled the achievement of a more inhomogeneous increase in temperature.