BS EN 60674-3-4. Specification for plastic films for electrical purposes. Part 3. Specifications for individual materials. Sheets 4 to 6: Requirements for polyimide films used for electrical insulation|Dielectric strength, Thickness, Classification systems, Thermal testing, Dimensions, Dielectric materials, Melting point, Solid electrical insulating materials, Temperature, Plastics, Electrical resistivity, Polyimides, Stability, Density, Dissipation factor, Film properties testing, Electrical properties of materials, Dimensional tolerances, Insulating films, Tensile strength, Moisture, Endurance testing, Electrical testing, Dimensional changes, Electrical insulating materials, Designations, Thermoplastic polymers, Tensile testing, Type testing, Width, Permittivity, Plastic films, Elongation