JT/T280-2004 The Versatile and Environmentally Friendly Choice for Outdoor Coating Applications Thermoplastic Paint

What is Thermoplastic Paint?

Thermoplastic paint is a type of coating material that has unique characteristics due to its thermoplastic nature.

At room temperature, it is usually in a solid state. It is composed of thermoplastic resins (such as hydrocarbon resins), pigments for color, fillers, and various additives. When heated to a specific temperature range (commonly between 180 - 230°C), it melts into a viscous liquid that can be easily applied to surfaces.

Once applied, as it cools, it solidifies again, forming a durable and hard coating. It's widely used in applications such as road markings. For example, the thermoplastic paint used for painting lines on roads provides clear visual guidance for traffic. Some thermoplastic paints also have reflective properties (with the inclusion of glass beads) to enhance visibility, especially in low - light conditions like at night. It has good adhesion to surfaces like asphalt and concrete and can withstand abrasion, weather conditions, and heavy traffic, making it a long - lasting choice for many outdoor coating applications.

Advantages of Thermoplastic Paint

The advantages of thermoplastic paint are as follows:

1. Good adhesion: It can firmly adhere to various substrates such as asphalt and concrete, ensuring the integrity and clarity of the markings for a long time. This is crucial for the durability and legibility of road markings.

2. Long service life: The material is highly resistant to abrasion, impact, and weathering. It can maintain its performance and appearance for an extended period, reducing the need for frequent reapplication and saving maintenance costs. For example, in high-traffic areas, thermoplastic paint can withstand the continuous wear and tear of vehicles.

3. Quick drying: After application, it solidifies rapidly, usually within a few minutes. This allows for quick completion of the painting work and minimizes the disruption to traffic or other activities. It is especially important for road construction and maintenance projects where minimizing traffic congestion is a priority.

4. Bright color and good visibility: The paint can provide vivid colors, making the markings highly visible during the day. Additionally, when glass beads are added, it has excellent reflective properties at night, enhancing the safety of driving by enabling drivers to clearly see the markings even in low-light conditions.

5. Wide application range: It is suitable for a variety of surfaces and locations, including roads, parking lots, airports, and other transportation facilities. It can be used to mark different types of lines, such as lane dividers, stop lines, pedestrian crossings, and parking spaces.

6. Cost-effective: Although the initial investment in equipment and materials may be relatively high, considering its long service life and low maintenance requirements, it is cost-effective in the long run. Moreover, the availability of raw materials and the maturity of production technology contribute to its relatively stable price.

7. Environmental adaptability: It can perform well in different environmental conditions, such as high and low temperatures, humidity, and rain. It is not easily affected by extreme weather, ensuring the stability and reliability of the markings.

Thermoplastic Paint Application Processes

1. Surface Preparation

- Before applying hot - melt coating, it's crucial to prepare the surface properly. The surface should be clean, dry, and free from dust, grease, and other contaminants. For example, in road - marking applications, the road surface is usually swept and washed to remove debris and oils. Any loose materials or old coatings that may affect the adhesion of the new coating need to be removed. This can be done through methods such as sandblasting for more stubborn old coatings or using a high - pressure water jet.

2. Melting the Coating

- The hot - melt coating is usually in a solid state at room temperature. It needs to be heated to a molten state for application. The coating is placed in a special heating device, such as a hot - melt kettle. The temperature is carefully controlled according to the type of coating and the manufacturer's instructions. Generally, the temperature range is between 180 - 230°C (356 - 446°F). During the heating process, the coating gradually melts and becomes a viscous liquid. Stirring is often required to ensure the even distribution of all components and to prevent local over - heating or burning of the coating.

3. Application Methods

(a) Spraying

- Spraying is a common method when a smooth and even coating is required over a large area. The molten coating is pumped through a hose to a spray gun. The spray gun atomizes the coating into fine droplets and sprays it onto the surface. The pressure and nozzle settings of the spray gun need to be adjusted according to the viscosity of the coating and the desired thickness of the coating. The distance between the spray gun and the surface also affects the quality of the sprayed coating. Usually, a distance of about 20 - 30 cm (7.9 - 11.8 inches) is maintained to ensure proper atomization and coverage.
- One advantage of spraying is that it can cover complex shapes and uneven surfaces relatively easily. However, it requires careful control of the spraying parameters to avoid over - spraying or an uneven coating due to wind or other factors.

(b) Scraping

- Scraping is suitable for applications where a thicker and more precisely shaped coating is needed. A tool such as a squeegee or a trowel is used. The molten coating is poured onto the surface and then spread and shaped by the scraping tool. The operator needs to have a certain level of skill to ensure the coating has a uniform thickness and smooth surface. For example, in creating road markings such as zebra crossings, the scraping method is often used to ensure the lines have the correct width and thickness.
- The thickness of the coating by scraping can be adjusted according to the specific requirements. Usually, the thickness can range from a few millimeters to several centimeters, depending on the purpose of the coating.

(c) Extrusion

- Extrusion is mainly used for creating three - dimensional or raised profiles of the coating. The molten coating is forced through a shaped die or nozzle. This method is often used in making raised pavement markers or other safety - related markings that need to be more prominent. The extrusion rate and the shape of the die determine the final shape and size of the extruded coating. The temperature and viscosity of the coating need to be carefully controlled to ensure a continuous and smooth extrusion process.

4. Cooling and Solidification

- After the coating is applied, it needs to cool and solidify to form a durable layer. The cooling process is usually a natural process that depends on the ambient temperature. In some cases, especially in industrial applications where a faster production cycle is required, forced - air cooling or other cooling methods may be used. As the coating cools, it gradually returns to a solid state, and its physical and chemical properties such as hardness and adhesion are fully developed.
- The time required for cooling and solidification varies depending on the thickness of the coating, the ambient temperature, and the type of coating. Thicker coatings generally take longer to solidify. For example, a thin - sprayed coating may solidify within a few minutes, while a thick - scraped or extruded coating may take tens of minutes to an hour or more to fully solidify.

5. Post - treatment (if necessary)

- In some cases, post - treatment may be required to improve the performance of the coating. For example, in reflective coatings, after the base coating has solidified, glass beads are sometimes spread on the surface to enhance the night - time reflective effect. The beads are carefully distributed and pressed into the surface to ensure good adhesion and maximum reflectivity. Another possible post - treatment is the application of a protective topcoat in some high - wear or high - exposure applications to further enhance the durability and chemical resistance of the coating.

Technical Specification