Most manufacturers won’t disclose the reason for why UV is more important than brand advertising. The core determining factors are actually the UV coating process and thickness.

1. The additive process directly determines the protective lifespan.

Currently, there are three mainstream additive processes in the industry, with vastly different effects:

Outdated coating process: UV agent is directly sprayed onto the surface of the finished board. It is easily washed away by rain and wind, generally failing within a few months, resulting in a board lifespan of less than 3 years.

Mixed co-extrusion process: UV raw materials are directly mixed into the PC raw materials and extruded together. The distribution of UV-resistant particles is uneven, and the protective ability is dispersed, resulting in a lifespan of only about 5 years.

In-film composite co-extrusion process: This is currently the optimal process. A dense and independent UV protective layer is formed directly on the board surface during extrusion molding, providing uniform and stable protection. The normal lifespan can reach over 10 years, and top-tier thick-coated products can even reach 15-20 years.

2. UV Layer Thickness Directly Determines Aging Time

Theoretically, the thicker the UV coating, the longer the anti-aging time. There are industry-recognized reference standards:

For standard 10-year warranty products, the UV coating thickness is approximately 50μm. Assuming a loss of 2-3μm per year, this provides effective protection for over 10 years.

High-end engineering-grade products achieve 80-200μm double-sided UV coatings. After 8000 hours of accelerated aging testing with xenon lamps (simulating 15 years of natural sunlight), the light transmittance decreases by less than 1%, supporting stable use for 15-20 years.

3. Single-sided or Double-sided UV? The difference is bigger than you think. Ultraviolet (UV) radiation isn’t just direct; 40% comes from diffuse reflection from the ground and buildings, which can damage the back side of the board. Therefore:

Boards with a UV coating on only one side: will be continuously damaged by diffused UV radiation from the back, shortening their actual lifespan by 3-5 years compared to the theoretical value;

Boards with a double-sided UV coating: not only block UV radiation from all angles but also prevent workers from confusing the front and back during installation, allowing them to fully realize their designed lifespan and making them more recommended for outdoor use.

**If you would like to know the advantages of polycarbonate sheets, please kindly check the post [What are advantages of polycarbonate sheets?]