Specific examples of a resin for the elastic belt include, for example: polycarbonate; fluorocarbon resins such as ETFE and PVDF; styrene resins (polymers or copolymers including styrene or a styrene substituent) such as polystyrene, chloropolystyrene, poly-??-methylstyrene, a styrene-butadiene copolymer, a styrene-vinylchloride copolymer, a styrene-vinylacetate copolymer, a styrene-maleate copoly