In the application of hot-melt marking paint, foam often occurs. The large ones are like soybeans and the small ones are like white sesame. Although such defects do not endanger the service life, they will affect the appearance carefully. This is also a difficulty that has puzzled the marking people all the time!

Through many years of practical activities, field communication, expert interviews, combing and summarizing, it is found that the bubbles in road markings mainly come from four levels: one way to detect where the bubbles come from and one shortcut to reduce bubbles. The in-depth analysis is as follows:

1、 Four levels of bubble formation:

1. The gas in the ground gap is caused by heat:

When the material temperature is within 200 ℃, glue (cover) is applied to the ground to produce road markings. At the same time, it takes 3-8 minutes for the road markings to be dry. Here, the gas in the ground gap is heated and expanded to the top within a few minutes.

Refer to the plan and scheme for treatment: raise the material temperature by 5-10 degrees, improve the leveling of architectural coatings, reduce the viscosity of paint coatings and let the bubbles out; Or reduce the mold temperature by 5-10 degrees to improve the viscosity of architectural coatings. No bubbles are allowed to top up and stay in the road markings!

2. Bubbles will be formed when the road is wet and cold:

The moisture in the wet and cold ground will volatilize and cause bubbles when encountering heat. The engineering construction can only be carried out after the ground is dry. In the early and late winter, special attention should be paid to the wet and cold degree of the ground.

3. Bubbles will also form when the bright oil is not dry:

Before the bright oil is dry, the organic solvent in the bright oil is not fully evaporated, and bubbles will be formed in case of heat evaporation. Only when the bright oil is fully dry and manic can it be scratched. Otherwise, in addition to bubbles, it is also easy to cause the burning and explosion of the bright oil that is not dry and manic, resulting in accidents!

4. Asphalt concrete is easy to cause bubbles when heated:

Taking the expressway as an example, asphalt concrete is usually used for the expressway, and the modified material usually forms bubbles when heated. In case of in-depth analysis by the community owner, the soybean oil (or edible oil) up and down by one thousandth can be added when burning the material, the tensile strength of the road marking can be abandoned, and the leveling of the material can be improved, so as to reduce the bubbles to meet the requirements of the community owner.

2、 How to detect where bubbles come from

Detecting bubbles is mostly the problem of material or the ground: you can use the same material to try to draw a knife on the aluminum alloy plate or stainless steel plate. If there is no bubble, it is not the problem of material! You can also push the cart to other roads to draw a small section to carry out the test!

3、 A shortcut to reduce bubbles

When the ground is dry and the bright oil is dried, bubbles occur. A new way to reduce bubbles is to adjust the mold temperature, or add one thousandth of soybean oil up and down when burning the material to adjust the leveling of the material.