Why does hot melt marking paint change color

The discoloration of hot-melt marking coatings is a common occurrence. Next, let me give you a brief analysis of this situation. The specific color change of hot-melt marking paint is that the white marking color turns yellow and the yellow marking color turns dark, which not only affects the visual recognition of the marking, but also causes a decrease in adhesion and durability. The reason for this situation is mostly due to the deterioration of organic substances such as resin, titanium dioxide, and other additives in hot melt coatings under high conditions, and the long-term exposure of hot melt coatings to ultraviolet radiation.

Hot melt coating
It is not difficult to prevent such problems as long as the heating temperature and construction conditions are mastered. The color change of hot melt marking paint can be controlled within the specified quality range. The heating temperature of the marking paint in the hot melt kettle should be 180 ℃ -230 ℃. After 5-10 minutes of rotational mixing, the material is loaded and scratched. If the temperature is too high or the burning time is too long, the organic matter in the paint will change its characteristics and cause color change. This requires careful operation and construction during the heating and construction process.
The products provided by the manufacturer should be made of heat-resistant and crack resistant materials, and the color of the resin and whether the filler can meet the fineness requirements at high temperatures should be checked. In recent years, construction experience has shown that the heat-resistant and crack resistant performance of petroleum resin is slightly worse than that of resins. Hot melt marking should have UV resistance, such as using rutile type titanium dioxide or using additives with UV resistance to improve marking materials, which is also a reasonable method to prevent discoloration of hot melt marking coatings.