The glass beads spread on the paint quickly after the road is painted. Glass beads for road marking with large diameter can be seen on the surface, while beads with small diameter will be embedded in the paint. The application of glass beads for road marking is very important to obtain road paint with high reflection. If glass beads cannot flow freely, it is impossible to disperse them in the paint. Due to the hydrophilic - OH group on the surface of glass, water may agglomerate small glass beads. The surface of glass beads can be modified by hydrophobic coating to prevent agglomeration. However, the adhesion between the coating and the paint on the glass surface should be strong. Otherwise, glass beads can be easily removed in traffic due to friction. Therefore, when hydrophobic materials are used to coat the glass beads for road marking, the retroreflectance will decrease. In order to overcome this problem, adhesives are used in some cases. However, the adhesive produces a thick coating on the glass surface and the retroreflective property is reduced again. In addition, the adhesive can agglomerate due to its hydrophilicity.
At the initial stage of use of paint and glass beads for road marking, large glass beads can be easily seen on the paint surface and the reverse reflection is high. After the wheels have rolled over the paint, the paint and glass beads for road marking start to wear, which results in reduced reflectivity. When the glass beads for road marking are removed from the paint surface, the gap is filled with dust. As a result, the paint will begin to darken and the visibility will decrease both during the day and night. If the surface of the glass bead is not modified, the adhesion between the glass and the paint will be weakened and the glass beads will be easily removed from the paint surface. The state of glass beads in the container is a group of colorless loose spherical particles. It should be clean and free of sundries, and it should not contain agglomerates that will not collapse after slight impact. Appearance requirements: according to the method specified in this standard, the glass beads should be colorless, transparent, smooth and round spheres with no obvious bubbles or impurities inside.