As a result of their molecular structure, dielectric materials are poor conductors of heat. As they are frequently processed at high pressures and temperatures, the development of an innovative heating process to overcome their poor thermal conductivity would constitute an important advantage. Heating with microwaves is an example of such a process. Depending on the molecular structure or chemical composition, a polar or conductive material is capable of absorbing microwaves. Microwave technology therefore enables these plastics to be heated with a significantly shorter process time and higher energy efficiency than conventional technologies. The long wavelength and resulting high penetration of the microwaves in these materials means that volumetric heating can occur. The poor thermal conductivity of the materials, which generally prevents the rapid heating of large masses, is rendered unimportant in the transfer of energy via microwaves.
