Alibaba.com data categorizes the Sun Sheets & PC Embossed Sheets category (ID: 100005333) as a definitive 'star market'. This classification is backed by a remarkable 37.99% year-over-year increase in active buyers and a consistently high supply-demand ratio, indicating robust and growing global interest. The trade volume is substantial, with leading sellers reporting annual GMV in the millions of US dollars. However, beneath this glittering surface lies a critical paradox that threatens to cap the market's potential: a significant trust deficit rooted in a persistent product quality issue—UV-induced yellowing.
This paradox is starkly evident in consumer feedback channels. A deep analysis of Amazon.com reviews for top-selling polycarbonate roofing sheets reveals a recurring theme: initial satisfaction with light transmission and ease of installation quickly turns to disappointment as the sheets begin to yellow within 12-24 months of exposure to sunlight. One verified purchaser lamented, 'Great for the first year, then they turned an ugly yellow. It looks terrible and ruins the whole aesthetic of my greenhouse.' This sentiment is echoed across numerous reviews, pointing to a fundamental gap between marketing promises and real-world product longevity. The core issue, as confirmed by industry leaders like Palram, is inadequate or poorly applied UV protection layers [4].
“The primary cause of polycarbonate sheet yellowing is the degradation of the polymer by ultraviolet (UV) radiation from the sun. Without a proper, co-extruded UV protective layer, the material will inevitably discolor, become brittle, and lose its optical clarity.”

