| 1 | EPDM Rubber | Frame perimeter, junction-box sealing, cable-entry seals | Strong resistance to outdoor weathering, ozone, moisture, and ultraviolet exposure | Suitable for long-term exterior exposure; formulation and compression set must be checked for the intended temperature range | ASTM D2000 ISO 3302-1 IEC 61730 | Framed crystalline-silicon modules installed in outdoor environments |
| 2 | Silicone Rubber | Junction boxes, cable glands, perimeter interfaces, serviceable seals | Wide operating-temperature capability and good resistance to ultraviolet radiation and oxidation | Low compression set and appropriate adhesion are important; silicone is generally more permeable to gases than many organic rubbers | ASTM C920 UL 94 IEC 61730 | High-temperature locations and components requiring flexible, durable sealing |
| 3 | Thermoplastic Elastomer | Co-extruded frame seals, edge seals, snap-fit sealing profiles | Can combine elastic behavior with thermoplastic processing and efficient profile production | UV stability, creep resistance, weld-line strength, and compatibility with glass and aluminum should be validated | ISO 3302-1 UL 94 IEC 61215 | High-volume module assembly using customized extruded profiles |
| 4 | Butyl Rubber | Moisture barriers, backsheet interfaces, secondary seals | Very low gas and moisture permeability compared with many conventional elastomers | Excellent barrier performance, but surface tack, flow at elevated temperature, and long-term dimensional stability require evaluation | ASTM D2000 IEC 61215 IEC 61730 | Applications where water-vapor protection is a primary design objective |
| 5 | Neoprene Rubber | Electrical enclosures, cable-entry parts, protective interface seals | Balanced resistance to weathering, abrasion, oils, and moderate chemical exposure | Outdoor UV performance varies by compound; temperature capability and electrical insulation requirements must be verified | ASTM D2000 UL 94 IEC 61730 | General-purpose sealing where mechanical toughness and environmental resistance are required |
| 6 | Fluorosilicone | Specialized seals exposed to fuels, oils, or aggressive contaminants | Silicone-like temperature flexibility with improved resistance to hydrocarbon-based fluids | Usually selected for demanding chemical environments; higher material cost and application-specific bonding checks are common | ASTM D2000 ISO 3302-1 IEC 61730 | Specialized photovoltaic systems near industrial, transport, or chemically contaminated environments |
| 7 | Thermoplastic Polyurethane | Thin edge seals, cable protection, flexible interface components | High abrasion resistance, strong tear resistance, and good flexibility | Hydrolysis resistance, UV stabilization, and long-term creep behavior are critical for outdoor photovoltaic use | ISO 3302-1 UL 94 IEC 61215 | Compact sealing components requiring toughness and precise molded or extruded geometry |
| 8 | Fluoroelastomer | Specialized high-performance seals and harsh-environment interfaces | High resistance to heat, chemicals, and many aggressive fluids | Higher hardness, cost, and compression-force requirements may affect design; low-temperature flexibility must be checked | ASTM D2000 ISO 3302-1 IEC 61730 | Specialty photovoltaic equipment exposed to high heat or aggressive chemicals |
| 9 | Closed-Cell Silicone Foam | Compression seals between dissimilar surfaces and enclosure covers | Lightweight cushioning with a degree of moisture resistance and tolerance for surface irregularities | Cell structure, density, compression-deflection behavior, and recovery after prolonged compression must be controlled | ASTM D1056 UL 94 IEC 61730 | Sealing assemblies that require gap compensation and low assembly force |
| 10 | Polyolefin-Based Sealant | Backsheet edges, encapsulant interfaces, and integrated sealing layers | Low moisture absorption and compatibility with several polymer-based module materials | Adhesion, thermal expansion, water-vapor transmission, and compatibility with encapsulants must be tested as a complete system | IEC 61215 IEC 61730 ISO 4892-3 | Glass-glass and polymer-interface designs requiring integrated moisture management |