Road marking paint is an important part of urban infrastructure, used to delineate lanes, guide traffic, mark pedestrian passages, etc. However, during construction and use, many people found that road marking paint would get hot, which aroused widespread concern and discussion. So, why does road marking paint get hot?
This article will discuss in detail the composition, construction methods, environmental factors and chemical reactions of road marking paint to reveal the reasons for its heating.
What are the ingredients of road marking paint?
First, understand the composition and type of road marking paint, which is the basis for understanding why it gets hot. Road marking paint is usually composed of the following main ingredients:
1. Resin: Resin is the main film-forming substance of marking paint, and common ones are acrylic resin, epoxy resin, etc.
2. Pigment: Pigments give marking paint color, and common ones are titanium dioxide, lead chrome yellow, etc.
3. Filler: Fillers are used to increase the thickness and strength of the paint film, such as calcium carbonate, talcum powder, etc.
4. Solvent: Solvents are used to adjust the viscosity of the paint, and common solvents include benzene and ketone.
5. Additives: Additives are used to improve the performance of the paint, such as plasticizers, stabilizers, etc.
According to the different ingredients and construction methods, road marking paint can be divided into three types: hot melt marking paint, solvent-based marking paint and water-based marking paint.
Why does road marking paint get hot?
● Construction and heat generation of hot melt marking paint:
Hot melt marking paint is the most widely used one, and its heating cause is closely related to the construction process.
1. Construction temperature: Hot melt marking paint needs to be heated to 180℃ to 220℃ to melt and reach a construction state. During the construction process, the hot melt equipment will heat the marking paint to a high temperature, and the temperature of the melted marking paint is extremely high when it is laid. This high temperature state itself is one of the main reasons for the heating of the marking paint.
2. Rapid curing: After high temperature construction, hot melt marking paint cools quickly and cures quickly. During the cooling process, heat is dissipated to the outside, making the surface temperature of the marking paint high for a short time, generating a sense of heat.
3. Frictional heat generation: During the construction process, the construction equipment and the road surface are in contact and friction, which will generate a certain amount of heat, further increasing the temperature of the marking paint.
● Heat sources of solvent-based and water-based marking paints:
Although the construction temperature of solvent-based and water-based marking paints is low, they will also generate heat in some cases.
1. Solvent volatilization: During the construction and drying process of solvent-based marking paints, the solvent will gradually evaporate. During the evaporation of the solvent, the surrounding heat will be absorbed, resulting in a local temperature increase. In addition, some solvents may produce exothermic reactions during the volatilization process, further increasing the temperature of the marking paint.
2. Chemical reaction: Whether it is solvent-based or water-based marking paint, chemical reactions will occur during the curing process, such as oxidation reaction, polymerization reaction, etc. These reactions sometimes release heat, causing the surface temperature of the marking paint to rise.
3. Sunlight exposure: After the marking paint is exposed to sunlight, some components in the pigment will absorb the heat of sunlight, especially in summer or hot weather, the surface temperature of the marking paint will rise significantly.
● The impact of environmental factors on the temperature of road marking paint:
1. Air temperature and ground temperature: High temperature and heat waves will cause the road surface temperature to rise, which will also cause the temperature of road marking paint to rise. In the hot summer, the road surface temperature often reaches above 50℃, which will significantly affect the temperature of road marking paint.
2. Traffic volume and friction: High traffic volume will increase the friction between the road surface and the road marking paint, and frictional heat will also cause the temperature of road marking paint to rise. Especially during emergency braking and acceleration, the friction between the tire and the road marking paint is more intense, and more heat is accumulated.
3. Environmental humidity: In a high humidity environment, the solvent or water in solvent-based and water-based road marking paint evaporates more slowly, and the heat generated during the volatilization process is difficult to dissipate quickly, resulting in a high surface temperature of the road marking paint.
Case analysis: Example of hot melt road marking paint construction
In order to better understand the specific reasons for the heating of road marking paint, let's take a look at a case in actual construction.
In a road marking construction project in a certain city, the construction team used hot melt road marking paint. The temperature was 30℃ and the sun was strong during construction. The construction equipment heats the marking paint to 200℃ and then quickly lays it on the road surface. Due to the high temperature of the marking paint, construction workers must wear protective gloves and protective clothing to avoid burns.
After the construction is completed, the marking paint begins to cool in just a few minutes, but still maintains a high temperature. At this time, the on-site thermometer shows that the surface temperature of the marking paint is about 60℃. This high temperature state lasts for about half an hour until the marking paint is completely cooled.
Conclusion on the heating of road marking paint
In summary, the reasons why road marking paint becomes hot during construction and use include high-temperature construction, solvent volatilization, chemical reactions, sunlight exposure, and environmental factors. In particular, hot-melt marking paint, its high-temperature construction and rapid cooling process are the main causes of its heating. Although solvent-based and water-based marking paints have lower construction temperatures, they also generate heat during the drying and curing process.
In order to ensure construction safety and marking quality, appropriate protective measures and construction strategies need to be taken to reduce the impact of high temperatures on construction workers and marking paint. By reasonably arranging the construction time, using cooling equipment and wearing protective equipment, the heating problem of marking paint can be effectively reduced, ensuring the smooth progress of road marking construction and the safety of road traffic.