Will Polycarbonate Sheets Turn Yellow Over Time? How Long Does It Take?

Like most polymer-based materials exposed to long-term outdoor conditions, polycarbonate sheets may experience a certain degree of yellowing over time. This is a natural aging phenomenon caused by factors such as ultraviolet exposure, weather conditions, temperature variation, and environmental pollutants. Even high-quality white or transparent materials can gradually develop slight discoloration after years of use.

However, the yellowing performance of premium polycarbonate sheets is carefully controlled through raw material selection and UV protection technology. High-quality polycarbonate sheets typically maintain a yellowing index of approximately ΔE≤3 after five years of testing under standard conditions.

According to common industry standards, an annual yellowing rate within approximately 5% is generally considered normal for outdoor applications. Transparent and white sheets usually show yellowing more noticeably over extended service life because color changes are easier to detect on lighter surfaces.

For projects where long-term appearance consistency is especially important, GWX generally recommends choosing tinted or colored sheets, such as bronze, grey, blue, or other darker shades. Even if slight aging or yellowing occurs over time, it is typically far less visible compared with clear or white panels.