Why Glass Curtain Walls Must Use Silicone Instead of PU (Polyurethane)

Glass curtain walls require high-performance sealing materials, and silicone is preferred over polyurethane (PU) for several key reasons:

1. Weather Resistance and UV Protection
   Silicone has exceptional UV and weather resistance, allowing it to withstand long-term exposure to sunlight and harsh weather conditions without aging or discoloration. While PU also has some weather resistance, its UV resistance is weaker, and it tends to degrade over time, which reduces its sealing performance.

2. Elasticity and Flexibility
   Glass curtain walls expand and contract slightly due to temperature fluctuations, wind, and other environmental factors. Silicone is highly elastic and flexible, which allows it to accommodate these movements and maintain a reliable seal over time. PU lacks the same level of elasticity and is prone to cracking or losing its sealability when exposed to these changes.

3. High and Low-Temperature Resistance
   Silicone performs well in extreme temperatures, from -60°C to +200°C, ensuring its long-lasting performance even in harsh conditions. PU tends to become brittle or lose its flexibility in extreme heat or cold, which can cause the seal to fail.

4. Water Resistance and Waterproofing
   Silicone offers excellent water resistance and does not deteriorate from exposure to moisture, making it ideal for sealing glass curtain walls. PU is less water-resistant and can swell or soften when exposed to prolonged moisture, leading to compromised sealing performance.

5. Long-Term Stability
   Silicone maintains its sealing properties for many years, making it ideal for long-term applications. PU typically requires more frequent checks and replacements, especially in challenging environments.

In summary, the weather resistance, elasticity, temperature tolerance, and waterproofing properties of silicone make it the ideal choice for sealing glass curtain walls.