What properties in a plastic indicate microwave transparency. Is it just dielectric constant and dissipation factor. Can anyone recommend a good microwave transparent plastic that is readily available other than UHMPE
Dielectric constant is a primary selection factor indicating loss or attenuation. Then again consider what is the materials function(what is it used for), rigidity, flexibility, weatherability, UV suceptibility (change properties from exposure), toxicity, thermal characteristics. Material cost and manufacturability. Just a few of the considerations to revue. Make a list of the plastics that are candidates, check the properties of each against your requirements. Make necessary tradeoffs and make your selection.
I hope this helps some.