With the accelerated global transition to renewable energy, the application of photovoltaic solar systems in renewable energy is rapidly increasing. A photovoltaic solar system needs to operate stably in an outdoor environment for more than 25 years, and the durability of not only the battery components but also the sealing system determines the life and efficiency of the photovoltaic solar system. EPDM rubber gaskets have become the core choice for photovoltaic system seals due to their excellent weather resistance, temperature resistance, and waterproof properties. Therefore, it is necessary to clarify the precise customized adaptation conditions of EPDM rubber gaskets to help the customization of rubber gaskets in the photovoltaic industry.
1. Consequences of seal failure of photovoltaic system
PV modules are exposed to the open air all year round, and their sealing materials must withstand:
Continuous UV radiation: causes most rubber materials to age, crack, and chalky.
Extreme temperature cycling: From 70°C+ in the heat to -40°C in the cold, materials are required to have excellent elasticity retention.
Wind, rain, moisture and salt spray erosion: Especially in coastal areas, water vapor and salt penetration can cause corrosion of internal circuits.
Ozone and chemicals: Atmospheric ozone and chemical pollutants in certain environments can accelerate rubber degradation.
Once the seal fails, it will lead to: water ingress inside the module, causing corrosion of cells and circuits, resulting in power degradation or even failure.
Delamination and blistering, affecting light absorption and structural integrity of components. The electrical insulation performance is reduced, increasing safety hazards.
The end result is a sharp drop in system power generation, a surge in maintenance costs, and a significant increase in the return on investment cycle.
2. The reason why the photovoltaic seal chooses EPDM rubber
Among the many elastomers, the molecular structure of EPDM rubber determines that it is inherently built to meet the above challenges.
It has superior weather resistance and UV resistance
The backbone of EPDM is made up of saturated carbon-carbon bonds and does not contain double bonds, which means it is not easily damaged by UV light and high ozone environments. Its exceptional anti-aging properties ensure that the gaskets do not crack or become brittle due to climatic reasons throughout the life cycle of the photovoltaic system, which is unmatched by ordinary PVC or natural rubber.
Excellent high and low temperature resistance
EPDM rubber gaskets typically maintain their elasticity and sealing capabilities over a wide temperature range of -50°C to +150°C. This ensures that the gaskets fit snugly and do not lose their sealing effect due to thermal expansion and contraction, whether in hot deserts or cold plateaus.
Extremely low moisture permeability with excellent waterproof sealing
EPDM material has a dense structure that can effectively block the penetration of water vapor, providing a reliable waterproof barrier for the junction box, frame connection, and BIPV system of photovoltaic modules.
Excellent electrical insulation
As a polymer insulating material, EPDM gaskets also provide additional electrical safety and prevent the risk of leakage.
3. The role of EPDM rubber gasket on photovoltaic solar system
Waterproof seal: Blocks water vapor intrusion and protects electrical safety
Core equipment such as photovoltaic modules, inverters, and combiner boxes all contain precision electrical components, and rainwater, dew, and moisture are the main safety hazards in outdoor environments. EPDM rubber gaskets form a tight sealing layer in the gaps of equipment interfaces and frames through customized structural design, completely blocking water vapor penetration, preventing short circuits, corrosion and other faults, and ensuring the electrical safety of the system.
Weather resistance and anti-aging: Resist extreme outdoor environmental erosion
Photovoltaic systems are mostly installed in outdoor scenarios such as rooftops and deserts, and face long-term tests such as ultraviolet exposure, alternating high and low temperatures, and ozone erosion. EPDM rubber itself has excellent UV resistance and ozone resistance, and can be formulated to further strengthen weather resistance during customized production, ensuring that the gasket will not crack, harden, or fail for a long time in the temperature difference range of -40°C~120°C, matching the design life of photovoltaic equipment for more than 25 years.
Shock absorption cushioning: mitigating vibration damage during installation and operation
Bolt fastening during PV module installation, slight vibration under wind action, and mechanical resonance during equipment operation may lead to wear on the module frame and bracket connection. Customized EPDM rubber gaskets can adjust the hardness according to the installation pressure, absorb vibration energy through their high elasticity, buffer the impact force, reduce component wear, and reduce noise conduction.
Insulation Protection: Isolate electrical risks and improve system safety
EPDM rubber has excellent electrical insulation properties, customized gaskets for junction boxes, connectors and other parts, which can effectively isolate metal components and electrical interfaces, prevent leakage and short circuit risks, and avoid electrochemical corrosion between metal parts and improve the overall safety factor of the system.
4. Specific applications of EPDM in photovoltaic solar systems
Component bezel sealing
During the assembly of photovoltaic panels, EPDM gaskets are used to fill and seal the gaps between the frames, ensuring that the entire structure is tightly connected, preventing moisture and other external factors from intrusion, thereby protecting the internal circuitry from damage.
Junction box protection
For junction boxes connecting individual photovoltaic modules, EPDM gaskets can provide the necessary insulation protection while also effectively resisting the effects of natural conditions such as UV radiation and rain erosion, extending the service life of the equipment.
Bracket fixation point cushioning
When installing photovoltaic arrays, EPDM gaskets are often used as a buffer layer at the contact point between the bracket and the roof or the ground, which can not only reduce the wear caused by vibration, but also help absorb the expansion and contraction stress caused by temperature differences, and avoid corrosion problems caused by direct contact with metal parts.
5. Key points of EPDM rubber gasket customization in photovoltaic system scenarios
Working condition parameters are provided accurately
Clarify the temperature range and ultraviolet radiation intensity of the installation site;
Indicate whether it is exposed to rain, snow, dust or light chemical media;
Provide installation inner diameter, outer diameter, thickness dimensions or 3D drawings to ensure a perfect fit between the gasket and the mounting slot.
Performance enhancements customization
Outdoor strong ultraviolet scenes: UV stabilizers are required to improve weather resistance;
Low temperature environment: customized low-temperature elastic formula to avoid hardening and brittleness;
High-frequency vibration scenarios: Choose EPDM materials with high elasticity and low compression set to extend fatigue life.
Structure and compliance customization
Structure customization: according to the installation method, choose flat pads, special-shaped pads, with lip edges, boss structures to improve the sealing effect;
Compliance requirements: Must comply with RoHS and REACH environmental protection standards in the photovoltaic industry, and medical-grade photovoltaic equipment must meet FDA certification;
Compression set rate: When customizing, it is necessary to obtain a compression set deformation rate ≤ 30% (70°C×24h) to ensure that the elastic seal can still be maintained after long-term use;
6. Correct selection and reasonable configuration of EPDM gaskets can improve the reliability of photovoltaic solar systems, reduce maintenance costs, and extend service life. If you have specific questions about EPDM gasket or any other rubber product customization, please feel free to contact us for professional advice and support.