The hot-melt markings shall be bright, uniform and clear no matter in the daytime or at night, with sufficient visual recognition distance. The visibility in the daytime depends on the quality of the pigment, which is relatively easy to solve. The visibility at night, that is, the reflection, first depends on the distribution quality of glass beads for road marking paint. It should be evenly and appropriately spread, because too much or too little will affect the reflective effect of the marking. Secondly, the temperature control during the marking construction is very important. If the temperature is too high, the fluidity of the coating will be stronger, that is, the dilution will be lower, the penetration will be higher, and the glass beads will settle faster, or even fall into the molten coating, so the reflective effect will be worse; If the temperature is too low, the glass beads will not adhere firmly, which can only ensure the immediate reflective effect after construction and will cause poor long-term reflection. Experience shows that half of the diameter of the glass bead is embedded in the film with the best reflective effect. But it's not easy to accomplish. Glass beads for road marking paint is influenced by coating temperature, thickness and climate conditions, so the spreading time shall be strictly controlled during construction. Pay attention to the equipment of distributing glass beads, as well as the impact of the wind force and wind direction (natural wind and the wind caused by passing through the vehicle from the side of the drawing vehicle) on the spreading of glass beads. Avoid the glass beads piling up. Spreading too much makes the color of the day bad, and make the products uneven, and it is also easy to make the dust stick and reduce the identification. The particle size, roundness and quality of glass beads are also important factors affecting the visibility.
1. Wear resistance. The car moving entirely depends on the friction between the wheel and the ground, which has a high demand for marking. The situation of the pavement in our country is more complex. The hard-damaged pavement, the walking of metal wheels, and the sand and muck on the road surface all have higher requirements on the wear resistance of pavement markings. For wear resistance, China's standard requires a weight loss of ≤ 50mg at 200R/1kg, while the Japanese standard JLS requires a weight loss of ≤ 200mg at 100R/1kg. Of course, for wear resistance, ensuring its visibility in the specified scope and time limit is ok.
2. Weather resistance. Thermoplastic coatings need to have excellent weather resistance. According to the climate diversity of vast area in China, that is, dry in the east, hot in the south and cold in the north and the characteristics of the road surface, the proportion of various raw materials of the coating can be adjusted to adapt to different climatic conditions and can be used in different seasons. The durability shall be corresponding to the expected value of the service time of the marking. For example, road marking shall be applied once every two years. When the best marking coating reaches about two years, most of coating will peel off, or the road subgrade will be free of traces after simple removal, so as to avoid the influence of the old line on the guidance of the new marking on the traffic flow, or a large number of hours will be consumed for removal.
The Use and Function of Glass Beads