Common causes of soft thermoplastic road marking paint
During the hot summer months, after thermoplastic road marking construction is completed, especially during the midday hours when road surface temperatures are highest, road markings may soften, experience reduced reflectivity, or even have glass beads detach. This not only affects traffic safety but also shortens the lifespan of the markings. The fundamental causes are primarily related to the Thermoplastic Powder Road Paint formulation, construction processes, and environmental conditions. The following is a detailed analysis and solutions.
1. Issues with the paint formulation
1.1 Insufficient resin content or poor resin quality
- Cause: Resin is the primary film-forming component of thermoplastic paint. Insufficient resin content or the use of resin with a low softening point can result in low coating hardness.
- Symptoms: The coating surface becomes sticky and easily removed by vehicle tires.
- Solution: Adjust the formulation to increase the resin ratio and select high-performance C5/C9 petroleum resin with a softening point ≥ 100°C.
1.2 Excessive plasticizer usage
- Cause: Plasticizers are used to improve flexibility, but excessive amounts reduce heat resistance.
- Solution: Reduce usage and select heat-resistant plasticizers (such as phthalate esters) to enhance high-temperature stability.
1.3 Unreasonable filler ratio
- Cause: Fillers such as calcium carbonate and talc enhance hardness and abrasion resistance, but insufficient ratios can cause the coating to become porous.
- Recommended ratio: 30%-50% of the total coating volume, ensuring uniform particle size.
1.4 Uneven pigment dispersion
- Impact: Causes local hardness variations and color differences.
- Solution: Improve pigment grinding and dispersion processes to ensure consistent color and physical properties of the coating.
2. Construction Process Issues
2.1 Insufficient Construction Temperature
- Standard Temperature: Thermoplastic Powder Road Paint must be heated to 180-220°C to fully melt.
- Countermeasure: Install temperature monitoring equipment to ensure complete melting of the coating.
2.2 Insufficient Coating Thickness
- Standard: Thickness should be maintained at 1.8-2.5mm.
- Countermeasure: Adjust the spray volume of the marking machine to prevent accelerated wear.
2.3 Inappropriate cooling speed
- Too fast: Prone to cracking.
- Too slow: Insufficient hardness.
- Countermeasure: Adjust construction time based on temperature and humidity; use water mist to accelerate cooling if necessary.
2.4 Improper road surface preparation
- Cause: Oil stains and dust reduce adhesion.
- Countermeasure: Thoroughly clean the road surface before construction and use primer to enhance bonding strength.
3. Environmental Factors
3.1 High-temperature environment
- In summer, asphalt pavement temperatures can exceed 60°C, causing low-softening-point resins to soften.
- Countermeasures: Use high-performance resins with a softening point ≥ 120°C or add heat-resistant additives.
3.2 UV aging
- UV radiation degrades resin molecular chains, leading to powdering and softening.
- Countermeasures: Add UV absorbers (e.g., benzotriazole derivatives) and antioxidants.
3.3 Rainwater erosion
- Long-term exposure to moisture can cause the coating structure to become loose.
- Countermeasure: Improve the hydrophobicity of the coating and add a waterproof coating for protection after application.
4. Storage and equipment factors
Coating storage: Store in a sealed, moisture-proof, and high-temperature-proof environment, and avoid using expired coatings.
Equipment maintenance: Ensure that the line marking machine is heated evenly, has sufficient pressure, and is regularly inspected and maintained.
Conclusions and recommendations
To prevent thermoplastic road marking paint from softening:
- Use high-quality resins and fillers to optimize the paint formula.
- Control construction parameters (temperature, thickness, cooling).
- Choose weather-resistant additives suitable for extreme conditions.
- Ensure proper surface treatment and equipment maintenance.
Why choose Huayuan?
Since its establishment in 2001, Henan Huayuan has focused on providing professional road marking machines and road marking paint solutions. Its products include hot melt road marking paint, thermoplastic powder road paint, road construction equipment, etc. It can provide a full set of customized construction support for various urban roads, highways, parking lots, port terminals and other projects, helping customers maintain high durability and high reflectivity of road markings even under complex conditions such as high temperatures and rainy seasons.
If you need customized road marking solutions, please contact Huayuan immediately!