Common Issues and Solutions for Hot-Melt Road Marking Paint

Hot melt coatings are widely used in road marking construction due to their excellent wear resistance, durability, and nighttime reflective properties. However, during the construction process or later use, it is inevitable to encounter some problems. As a professional supplier who has been deeply involved in the field of road marking for many years, TOP ROAD Transportation Technology Co., Ltd., with rich on-site experience and technical accumulation, has sorted out several common problems and core solutions of hot-melt marking coatings for you, aiming to help construction teams improve efficiency and ensure project quality.

1、 Yellow markings and insufficient whiteness
The color of the markings is not white or yellowed, which directly affects visual recognition. This is usually related to coating treatment, construction environment, and the material itself.

Long term boiling: In places where frequent intermittent construction is required such as intersections and factory areas, if the construction speed is slower than the boiling speed, the coating will be repeatedly or for a long time heated in the hot melt kettle, which can easily cause the resin to age and turn yellow. Solution suggestion: Optimize the construction organization and try to complete the laying out as much as possible before concentrating the material boiling and drawing; For work surfaces that cannot be prepared in advance (such as excavation and repair), it may be considered to use higher-level coatings that are more heat-resistant, and to use the method of low heat and slow boiling in the early stage.
Environmental and road pollution: Newly laid asphalt pavement may have asphalt oil seeping out due to rainwater erosion or vehicle crushing, contaminating the surface of the marking. Solution suggestion: Before construction, a simple test can be conducted and the situation should be explained to the owner. It is recommended to wait for the road surface to stabilize for a period of time before proceeding with the marking.
Moisture absorption during coating storage: If the coating is damp during storage, it will leave yellowing marks after application due to water evaporation, and a large amount of steam may be generated during boiling, posing a safety hazard. Solution suggestion: Ensure that the paint is stored in a dry and ventilated place. If it has been dampened, you can try mixing it with new materials in proportion for use on secondary roads, but be sure to open the feeding port and pay attention to safety when boiling.
Raw material and process control: The quality of raw materials such as resins and pigments (such as titanium dioxide) used in coatings, as well as the stability of the ratio during production, are the basis for determining the whiteness of the marking line. TOP ROAD Transportation Technology Co., Ltd. has a professional R&D team and a strict quality control system. We conduct random inspections on each batch of products to ensure stable quality of raw materials and finished products, reducing the occurrence of such problems from the source.
Hot melt coating for marking lines, common problems with hot melt coating for marking lines

2、 Bubbles appear on the surface of the marking line
Bubbles affect the aesthetic appearance and reflective uniformity of markings, and the root cause is the thermal expansion of moisture, air, or wet primer.

Damp ground or wet bottom glue: This is a common reason. Solution suggestion: Before construction, it is necessary to ensure that the road surface is completely dry and receives sufficient sunlight after rain; The base adhesive needs to reserve sufficient drying time according to the temperature.
Problems with the road surface itself, such as newly installed modified asphalt pavement, loose cement pavement, or excessive pavement gaps, can cause internal gas to expand and escape when heated, forming bubbles. Solution suggestion: For unavoidable road conditions, the leveling and viscosity of the coating can be adjusted by fine-tuning the material temperature (such as raising or lowering it by about 10 degrees Celsius) to help remove gas or suppress bubble ejection.

3、 The inverse reflection coefficient (inverse value) does not meet the standard
The poor reflective effect at night is related to driving safety. The inverse value is influenced by multiple factors.

The construction process is crucial: the material temperature directly affects the settlement of glass beads. High or low temperatures can cause excessive or insufficient settlement of glass beads, affecting reflection. TOP ROAD’s technical service team will remind customers to choose the optimal construction temperature based on the coating grade and season (such as increasing the material temperature appropriately in winter).
Selection and spreading of glass beads: Glass beads with high refractive index and high roundness should be selected, and the spreading amount should be strictly controlled. Uneven spreading, equipment blockage, or strong winds can all affect the effectiveness.
Thickness and pollution of markings: Thin markings can cause glass beads to not adhere firmly and fall off; If the surface is contaminated with dust and oil after construction, it will also seriously reduce the inversion value. It is necessary to wipe it with a special cleaning agent and measure it.
4、 Poor adhesion and easy detachment of markings
The detachment of markings is a serious quality issue, usually not caused solely by the paint.

Inconsistent construction conditions: Construction on damp, icy, oily or dusty roads is the main cause of detachment. Core principle: Before construction, it is necessary to ensure that the road surface is clean, dry, and solid.
Improper treatment of bottom glue: Applying hot melt coating without applying bottom glue, uneven application, or before it dries can greatly weaken adhesion. Especially on hydrophilic substrates such as cement pavement, qualified primer must be used.
Mismatch between road surface and coating: For special smooth or active substrates such as cement road surface, sidewalk bricks, granite, etc., the adhesion of hot melt coating is inherently insufficient. TOP ROAD will provide professional advice to customers based on its rich product line, such as recommending cold paint (solvent based) or two-component products with better adhesion matching in these scenarios to reduce later risks.
Incomplete melting of paint: The paint is “trapped” and the resin properties are not fully utilized, which can cause the marking to become brittle and the vehicle to easily break and fall off after being crushed.
Hot melt coating for marking lines, common problems with hot melt coating for marking lines

5、 Marking cracking and non wear resistance
Reflection cracks: If there are cracks in the roadbed or old line itself, newly drawn markings will have reflection cracks due to displacement of the base layer.
Seasonal material errors: The summer formula coating has high flexibility and may crack due to low-temperature brittleness when used in winter; The winter formula used in summer may be too soft and not wear-resistant. TOP ROAD will provide products that are suitable for the customer’s construction season.
Insufficient thickness: The marking thickness does not meet the standard, which is the direct cause of rapid wear and tear. Regular calibration of construction equipment is required to ensure uniform discharge.

Hot melt marking construction is a systematic project, with materials as the foundation, processes as the key, and environment as the variable. TOP ROAD Transportation Technology Co., Ltd. not only provides a full range of hot melt marking coatings with stable quality, but also is committed to transforming years of on-site problem-solving experience into pre guidance and full technical support for customers. Choosing TOP ROAD means that you not only receive the product, but also a reliable partner dedicated to the field of road safety. We are willing to work hand in hand with various engineering and construction teams, from pre construction preparation to post maintenance, to provide full protection and jointly create durable, safe and clear road markings.

Our company is a professional manufacturer of road hot-melt coatings, road retroreflective measuring instruments, and road marking machines. If you are interested, please feel free to communicate with me via email at any time export@toproadtraffic.com