Measurement of standing wave ratio for evaluation of microwave absorption efficiency by molding materials

The presented work includes results of standing wave measurement for evaluation of microwave absorption efficiency by molding materials. Initial research has been conducted using microwave gap line. It has been demonstrated that foundry quartz sands have minimal microwave absorption capability. The following binders used for research: bentonite „Geco” and bentonite „Specjal”, demonstrated the highest absorption of Pabs microwave power output of over 60% Pin. It has also been demonstrated that water content, constituting component of synthetic molding sands, significantly influences change of microwave absorption. We have established that application of this kind of measuring device may allow for precise determination of characteristic features, such as microwave absorption factor k, of various foundry materials as well as determination of their suitability in foundry processes, e.g. microwave formation of foundry molds and cores. Microwave gap line may also serve as a device for precise determination of water content as well as other molding sand components and for their identification with the use of characteristic parameters, e.g. reflection factor |Γk|.