Common Problems About Hot Melt Paint Construction In Summer

Common Problems about Hot Melt Paint Construction in Summer

May 10,2024

Common Problems about Hot Melt Paint Construction in Summer

1. Precautions for hot melt paint construction in summer

Hot-melt paint, as the name implies, melts when exposed to heat. (Substances that are solid at room temperature melt at a certain temperature and become liquid, which is called molten state.)

According to the current Chinese national standard Road Marking Paint JT/T280-2004, the softening point is 90-125 ℃.

After heating, hot-melt paint is applied to the road surface using a specific method, and the road marking is formed after the temperature is cooled to form a film and solidified.

When the ground temperature is as high as 50℃, 60℃, and 70℃, and the hot-melt paint just applied is cooled from 210-220℃ to 70℃, 60℃, and 50℃, the temperature of the road marking is difficult to continue to drop. At this time, people will feel that the coating film is soft and the marking line can’t be dry.

According to the recently released latest Chinese national standard, the compressive strength of hot-melt paint at 23°C must be ≥12MPa, but the compressive strength at 60°C only needs to be ≥2MPa to be qualified.

Therefore, it is normal for qualified hot-melt paint to have a compressive strength of ≤1 MPa at 70°C. Therefore, when hot-melt marking is applied in extremely hot weather, it is normal for the paint to dry slowly, become soft, and be able to be pinched by fingernails.

Solution:

a. Try to use hot-melt paint with a higher softening point and higher compressive strength;

b. Try to avoid construction during high temperature periods;

c. When encountering a road section that must be opened quickly, spray water to cool it down 3-5 minutes after marking.

2. Ensure that the initial retroreflectivity meets the standard

When hot-melt marking is applied in cold seasons, if the drop on glass beads can’t realize ideal settlement effect, it is usually necessary to increase the material temperature and increase the embedding depth of the glass beads to ensure the good retroreflectivity.

Similarly, when hot-melt marking is applied in hot seasons, due to the extended drying time, the drop on glass beads will be affected by the natural high temperature, and the glass beads will continue to sink, affecting the initial reflection of the marking.

Solution:

a. Use professional equipment such as retroreflectometer, increasing the frequency of self-inspection;

b. Use drop on glass beads with larger size distribution.

3. Choose the appropriate solution according to the construction site

For example, hot-melt markings in parking lots, toll plazas, or other places that are subject to static pressure from vehicles for a long time after being marked, not only face high ground temperatures in hot seasons, but also suffer from heat conduction from high-temperature tires. In addition, they are repeatedly rolled over by the heavy weight of the vehicle body, which easily produces (or leaves) indentations, affecting the appearance of the markings.

Solution:

For parking lots, toll plazas, etc. that are in a state of static pressure from vehicles for a long time, it is recommended to use normal temperature/water-based/two-component markings.

The ultimate purpose of installing and maintaining road markings is to improve road safety; for this, high-quality raw traffic safety materials are essential.

As a leading manufacturer of traffic safety materials with more than 30 years’ experience, Tory is committed to ongoing product development and excellent customer services that makes us the perfect partner for your road marking paint supply needs. We can provide you with raw materials (such as reflective glass beads, MMA resin, AW element etc.) with very competitive prices which can be customized to meet the specific requirements of customers and projects. For more information, or to get started on your traffic safety solution: https://www.cntory.com/