Common problems in marking construction: Reflection of markings (Part 1)

No one can explain the reverse reflection of markings thoroughly. Most people only know one thing and don’t know the other. I plan to use two articles to thoroughly clarify the relationship between markings, glass beads, and reverse reflection detection equipment. This article focuses on glass beads and anti reflection detection equipment. The first article involves, it must be liked and forwarded!

1、 The working principle of the surface scattering glass microbeads and reverse reflection detector.

1. At present, glass microspheres are classified by refractive index, with 1.5 refractions/1.5-1.6 refractions/1.7-1.9 refractions. Glass beads with a refractive index of 1.5 can meet 99% of usage requirements, and this is currently the most widely sold type on the market. Secondly, in terms of roundness and roundness, the higher the roundness, the better, and of course, the more transparent the better. No matter what kind of glass bead it is, it is essential to maximize the value of retroreflection as much as possible! (Ceramic Rain Night Beads are not discussed here. They are not the same structure as glass beads, but are an “assembly” composed of multiple parts. If interested, we will discuss them separately.)
2. The theoretical upper limit of the reverse reflection value for all glass bead types is approximately 280cd. lx. ㎡ (28000cd. lx. ㎡), and the theoretical upper limit of the reverse reflection value for 1.5 refractive glass bead types is approximately 2cd. lx. ㎡ (2000mcd. lx. ㎡). In reality, factors such as glass bead settlement (0.7), internal defects of glass beads (0.8), filling rate of marking lines (0.9), roundness/transparency of glass beads (0.8), and transmittance of marking lines (0.2-0.8) also affect the accuracy of the reflection value. Based on the above conditions, it can be roughly concluded that the reverse reflection value of 1.5 refractive beads in practical applications is between 2000 * 0.7 * 0.8 * 0.9 * 0.8 * (0.2-0.8)=645mcd.lx. ㎡ and 161mcd.lx. ㎡. As for why the theoretical upper limit values are 280cd. lx. ㎡ and 2cd. lx. ㎡, they involve complex optical principles and calculations, which are too lengthy to explain here. We can discuss them in detail when we have time.
3. The reverse reflection efficiency of glass microspheres with different refractive indices varies greatly, and the highest reverse reflection efficiency is achieved when the refractive index is 1.923. As for the reflectivity value of road markings, considering the economic benefits, 1.5 refracted glass microspheres are already sufficient to meet the vast majority of needs.

To sum up, glass microspheres with a refractive index of 1.5 can already meet the requirements (key factors include roundness, roundness, and transparency). As for the matching of glass bead size, both the material factory and bead manufacturer will provide reasonable suggestions based on your requirements. 1.5 Refractive glass beads have high requirements for coatings, and the factors that affect the retroreflection coefficient of the coating as a reflective layer of the glass beads account for 0.2-0.8. By using glass beads with a refractive index greater than 1.5, the reflectivity efficiency of the beads will be significantly improved. The reflectivity efficiency of 1.6 is 5 times higher than that of 1.5, and 1.7 is 15 times higher than that of 1.5 (Table 1). The DELTA detection equipment is more stable, and domestic products should pay attention to the level and angle of the equipment, road surface, and markings. The detection values can only be used as a reference and need to be combined with the actual feelings of the driver. Not all car models have an angle of 1.05 ° between the headlights and the eyes, and there are significant differences in the reflection brightness of the markings on different car models.

Our company is a professional manufacturer of road hot-melt coatings and road glass beads. If you are interested, please feel free to contact me via email at any time export@toproadtraffic.com