Epoxy sheet is also called insulating board, epoxy board, 3240 epoxy board. Epoxy resins generally refer to organic polymer compounds containing two or more epoxy groups in the molecule. Except for a few, their relative molecular mass is not high. The molecular structure of epoxy resin is characterized by the presence of active epoxy groups in the molecular chain, and the epoxy groups can be located at the end, middle or cyclic structure of the molecular chain. http://www.hcdurostone.com/epoxy-sheet/