The wave penetration into various materials has huge positive consequences in many applications. Volumetric heating gives rise to a very rapid energy transfer into the material being heated. In conventional heating, heat flow is initiated on the material’s surface and the rate of heat flow into the centre is dependent on the material’s thermal properties and the temperature differential. A conventional oven requires heating to temperatures much higher than is required by the material itself since there is asymptotical rise in workload temperature towards the required level.

In a properly designed applicator the majority of the available energy is dissipated into the workload. This results in lower conduction and convection heat losses and can represent energy savings of up to 70%.

Microwave heating power can be controlled instantly, giving better control of process parameters and heating profiles, as well as rapid start-up and shut down.

The rapid dissipation of energy – mainly into the workload – and the high energy densities capable in small volumes allows equipment to be up to 20% the physical size of conventional systems.

A material’s ability to be heated by electromagnetic energy is dependent on its dielectric properties, this means that in a mixture containing a number of differing constituents the heating of each will vary. This can have profound positive consequences on energy usage, bulk reaction temperatures, moisture removal and process simplification.

The energy transfer mechanism from electromagnetic to thermal energy is a function of a materials electrical properties. This allows a continuous dumping of energy into some materials and provided that heat losses can be controlled, very high material temperatures can be achieved with simple and relatively low power microwave generators.

The electromagnetic nature of microwave heating means that energy transfer to a material is usually via some form of polarisation effect within the material itself. This direct transfer of energy eliminates many of the problems associated with organic fuel usage for the end user.

Many chemical reactions can be accelerated using microwaves. Solvent free reactions are gaining popularity in many labs , thus reducing problems associated with waste disposal of solvents and other hazardous chemicals.