The thickness of ETFE (ethylene-tetrafluoroethylene copolymer) — ranging from 25μm to over 1mm, with composite structures reaching the millimeter level — directly determines its mechanical properties, light transmittance, etc. It is divided into three types for PV and other fields: Ultra-thin (25-50μm): Extremely lightweight, highly flexible, ~95% light transmittance, suitable for flexible PV encapsulation and portable energy equipment; Conventional (50-200μm): Balanced performance, accounting for over 70% of global consumption, used in BIPV membrane structures and rigid PV protection; Thick-walled/composite (200μm+): High strength and corrosion resistance, applied in PV power plant protection, industrial linings and special building load-bearing structures.