Vibration-type road reflective marking paint

Vibration-type road reflective marking paint

Before the new standard for road marking paints—JT/T280-2004—replaced the old standard—JT/T280-1995—in the transportation industry, vibration-type road marking paints had already been widely used on highways. Finally, in February 2005, these paints were given a formal identity and incorporated into the industry standards under the name “No. 3 Thermoplastic Raised-Type Road Marking Paint.” Vibration-type road marking paints are often also referred to as raised-line markings or night-rain markings. Based on their application patterns, they can be further classified into dot-shaped, square-shaped, and ribbed vibration markings.

1. Performance characteristics and application scope

1.1 Performance

1.1.1 Quick-drying property

Like thermoplastic road marking paints, vibration-type marking paints, after being coated and sprinkled with glass beads, should exhibit rapid drying properties within a short period (less than 5 minutes), regardless of the weather conditions. Generally, thermoplastic road reflective marking paints have excellent rapid-drying (curing) performance: they cure quickly in cold seasons but more slowly in warm seasons. If the coating cures too rapidly, it may warp and twist due to shrinkage, and the adhesion of the glass beads will also be compromised. On the other hand, if the coating cures too slowly, not only will the sprinkled glass beads sink into the paint, thereby reducing their reflectivity, but it will also adversely affect the shaping effect of the vibration-type marking paint.

1.1.2 Adhesion and Adhesion Mechanism

The marking coating must exhibit strong adhesion to the road surface, resisting peeling and cracking. It should adhere well to the pavement so that the coating does not easily peel off due to vehicle traffic, skidding, or braking. Moreover, it should remain intact and free from cracking or delamination even when subjected to thermal expansion and contraction of the road surface caused by seasonal temperature fluctuations. The vibratory-type road marking paint is heated in a hot-melt pot to a temperature ranging from 180°C to 230°C (the exact construction temperature varies depending on the raw materials used by different manufacturers), causing the thermoplastic resin in the paint to melt and transforming the paint into a molten, flowable state. The paint is then applied onto the road surface using a dedicated self-propelled marking machine, while simultaneously sprinkling glass beads onto the surface. After application, the coating cures at ambient temperature.

1.1.3 Visibility

The visibility of vibration-type road markings should be distinct, uniform, and clear both during the day and at night, with an adequate visibility distance. During the day, visibility depends on the quality of the pigment used; at night, visibility—specifically, reflectivity—relies primarily on the quality of glass bead distribution and the concentration of glass microbeads in the coating. The glass beads must be distributed evenly and in the right quantity; too many or too few beads will both impair the marking’s reflective performance. Experience has shown that when half of the glass beads’ diameter is embedded within the coating film, the reflective effect is optimal. Another distinctive feature of vibration-type road markings, one not found in conventional thermoplastic markings, is their enhanced visibility under nighttime and rainy conditions, significantly improving traffic safety performance on rainy nights.

1.1.4 Durability

Wear resistance. A vehicle’s forward motion relies entirely on the friction between its wheels and the road surface, and this friction places high demands on road markings. In China, road conditions are quite complex: there are roads with severe damage, metal wheels rolling over them, and sand particles and construction debris on the road surface—all of which impose stringent requirements on the wear resistance of road markings.

Regarding wear resistance, China’s standards require that the weight loss after 200 revolutions per 1 kg be no more than 50 mg.

(2) Weather Resistance: Vibrating pavement marking coatings must exhibit excellent weather resistance. Given China’s vast geographic expanse and diverse climatic conditions—ranging from humid east to dry west and from hot south to cold north—as well as the characteristics of road surfaces, the proportions of various coating ingredients can be adjusted to accommodate different climatic conditions, enabling construction and application throughout all seasons.

1.2 Applicability

Based on years of construction experience and experimental results, the following is a summary of the application scope of vibration-type marking paints:

Primarily used in areas prone to accidents and locations where high visibility of road markings is required—such as the edge lines of high-grade highways, curves, entrances and exits, tunnels, steep slopes, and other similar sections; as well as intersections on urban roads, lane demarcation lines, and boundaries of special-purpose lanes. The marking application should be determined based on road conditions and design requirements.

2. Composition of Vibratory Reflective Road Marking Paint

The composition ratio of the raw materials for vibration-type reflective road marking paint is as follows:

1. Thermoplastic petroleum resin: 13.5%

2. Glass microspheres: 20%

3. Pigment: 2.5%

4. Heavy calcium powder: 35%

5. Stone powder: 40%

6. Molding agent: 2.5%

7. DOP: 0.6%

8. Polyethylene wax 1.1%