Little knowledge that cannot be ignored in hot-melt marking coatings

The commonly used paint on the market is hot-melt marking paint, and there are some small knowledge that cannot be ignored. Hot melt marking coatings often produce bubbles during application. Although this defect does not affect the service life, upon closer inspection, it affects the appearance, which has troubled many construction team workers. The following little knowledge mainly focuses on the reasons for paint bubbles.

1. Heating of air in road gaps
   When the temperature is around 200 degrees Celsius, it takes 3-8 minutes for the hot melt type marking paint to be applied to the road for drying. Within these minutes, the fine gaps in the road will be heated by the air, causing the paint to expand. Those with large bubbles will burst the coating film and cause it to rupture; And the small bubble markings have dried and are left inside the marking coating or at the bottom of the marking, which only affects the appearance; The bubbles have just emerged from the film surface, and the coating has dried and left spots, which also affects the appearance. Solution: Reduce the material temperature by 5-10 degrees, increase the viscosity of the coating, prevent bubbles from rising, and leave them within the markings. Or increase the material temperature by 5-10 degrees to improve the leveling of the coating, reduce the viscosity of the coating, and allow bubbles to be expelled.
2. Asphalt is prone to heat exposure
   Nowadays, highways are being changed to asphalt roads for cooling purposes. Asphalt should have a heat absorbing effect and there will be no cracks on the road surface. When switching to asphalt roads, a modifier was added, which often produces bubbles when it encounters hot melt marking coatings. Solution: About one thousandth of soybean oil (or salad oil) can be added during the firing process, sacrificing the compressive strength of the marking and increasing the leveling of the material, in order to reduce bubbles and meet the owner’s requirements.
3. Wet ground
   The moisture in damp roads can evaporate due to heat, resulting in bubbles. Therefore, before construction, it is necessary to check the dryness of the road and pay attention to the humidity.
4. Alkaline heavy cement road
   Cement roads with excessive alkalinity can also cause blistering during the application of hot-melt marking coatings, as roads with excessive alkalinity can cause severe dust absorption. Clean thoroughly with a dust collector before construction.
5. Loose cement road
   The looseness of cement roads is a rare occurrence, and when it comes to it, it is considered a win. The only way to balance it is to apply a second coat of bottom oil and adjust the material temperature.
6. Bottom oil not dry
   Before the bottom oil dries, the solvent in the bottom oil is not completely evaporated, and it will produce bubbles when heated and evaporated. Scratching can only be carried out after the bottom oil is completely dry. Otherwise, in addition to causing bubbles, it is also easy to cause the undeveloped bottom oil to explode, leading to safety accidents.