In the micro-prism, the incident light needs to pass three total reflections to achieve the retro-reflection effect. For the triangular prism type, when the light hits the truncated angle structure of the triangular prism, only two total reflections can be completed, and no retro-reflection can be achieved.
The full prism type reflective material cuts off the three non-reflective truncated corners, and retains the core part that can be retroreflected. Through recombination, the full prism type reflective material can theoretically achieve 100% reflection.
China has issued a new national standard GB / T 18833-2012 for road traffic reflective film. The new national standard divides reflective films for road traffic into seven categories, three of which are glass microbead reflective films, and the other four are microprism reflective films. Each type of reflective film has different retroreflective coefficients due to different process technologies. The retroreflective coefficients are in order from low to high, engineering grade (lens embedded glass microbead type), high strength level (sealed capsule glass bead type) , Super grade (triangular prism type) and diamond grade (full prism type). At the same time, based on the differences in the weather resistance of the raw materials used in production, each type of reflective film also has a different service life.