Glass beads are a crucial reflective material in reflective road marking paints. Their reflection principle is that when headlights shine on the surface of the glass beads, the light source is projected into the glass beads, reaches the bottom of the bead, and comes into contact with the coating. The light is then reflected back by the vertical surface of the coating and onto the driver's eyes, allowing the driver to see the ground directly ahead even at night without streetlights.

I. Performance Requirements of Glass Beads:

Road marking paint manufacturers state that the GB/T24722—2009 standard, "Glass Beads for Road Markings," specifies the following regarding glass beads: Based on particle size distribution, glass beads are divided into three categories: Category 1 glass beads are suitable for surface application of hot-melt, two-component, and water-soluble road marking paints; Category 2 glass beads are suitable for premixed hot-melt, two-component, and water-soluble road marking paints; Category 3 glass beads are suitable for surface application of saturated solution-based road marking paints.

II. Working Requirements for Glass Beads in Road Marking Paint:

Road marking paint manufacturers state that when sprinkling glass beads onto the surface of road marking paint, 1/2 to 2/3 of the glass beads should be embedded in the coating to ensure a strong bond. The appropriate spreading amount of glass beads is 0.3~0.4 kg/m². Glass beads used in road marking paint are generally a mixture of glass beads of different sizes. This is because, after the paint film dries, the glass beads exposed on the surface have a reflective effect. As the road marking paint film gradually deteriorates, the larger glass beads on the surface fall off, and the smaller glass beads embedded within the paint film are polished and reflect light again, thus ensuring that the road marking paint maintains its reflective properties.