Understanding the Performance Standards for Conductive Shielding Silicone Foam Sealing Strips

In the photovoltaic industry, the performance standards for conductive shielding silicone foam sealing strips are crucial. These standards include tests for salt spray resistance, double-85 durability, surface resistivity, and volume resistivity. Additionally, the stability of silicone foam sealing strips under various harsh environments and the resistance to aging are critical for the end-use acceptance by photovoltaic companies. Below are the key performance requirements and test methods for a qualified conductive shielding silicone foam sealing strip.

Surface Resistivity Test for Conductive Shielding Silicone Foam Sealing Strips

Most conductive silicone strips undergo surface resistivity testing according to MIL-G-83528 standards. This standard outlines the equipment and sample length methods for testing surface resistivity. The average surface resistivity value for these strips should not exceed 4 ohms, with a maximum of 8 ohms. It's important to note that surface resistivity tends to increase with usage over time due to oxidation of the conductive fabric on the surface. This is why surface resistivity tests are conducted before shipment to ensure that the product maintains its electrical properties.

Thermal Air Aging Requirements for Conductive Shielding Silicone Foam Sealing Strips

Thermal air aging tests simulate the high-temperature environments silicone foam strips may encounter during actual use. These tests help assess the material’s performance stability under prolonged exposure to heat. According to GB/T 3512 standards, the strips must undergo testing at 70±2°C for 168 hours. After this aging test, the tensile strength of the sealing strip should remain above 3.35 MPa, and the elongation at break should not be less than 225%. Additionally, the weight loss during heating should be controlled to under 3%, ensuring no harmful VOC emissions are released. High-quality silicone material is essential to prevent cracking or degradation under these conditions.

Water Resistance Testing for Conductive Shielding Silicone Foam Sealing Strips

Water resistance tests measure the ability of the silicone foam strips to withstand water exposure without significant performance degradation. The silicone foam strip must maintain its physical and chemical properties, such as tensile strength, elongation, and compression resistance, when exposed to water or high humidity. For instance, when tested according to QC/T639 standards, the strip should remain stable after 120 hours in 80°C hot water, with the hardness variation staying within ±5° and tensile strength not falling below 85% of the original value.

Salt Spray Resistance Test for Conductive Shielding Silicone Foam Sealing Strips

The salt spray resistance test simulates corrosive environments, often found in coastal areas, to evaluate the long-term durability of silicone foam strips. The test involves placing the sealing strip under 30% compression and subjecting it to 30 days of salt spray exposure in a 5% NaCl solution, with alternating wet and dry cycles. The conductive shielding silicone foam sealing strip must withstand this test without leaks, corrosion, or significant physical damage, and it should maintain its waterproof and shielding performance at IP67 standards or higher.

Conclusion: Ensuring High-Quality Conductive Shielding Silicone Foam Sealing Strips

After passing rigorous tests such as smoke durability, water resistance, thermal aging, and surface resistivity checks, the conductive shielding silicone foam sealing strip meets industry standards for use in photovoltaic inverters and other applications. These tests ensure the product's reliability and long-term performance. While some initial samples may undergo verification testing, third-party reports are often sufficient to validate the quality of these products.

These silicone foam sealing strips serve as an essential component in providing sealing, water resistance, and electrical shielding in photovoltaic inverter enclosures. Their strict adherence to standards and durability testing ensures they meet the needs of the photovoltaic industry, offering high-quality solutions for energy applications.