Market change! What is the biggest difference between roll powder coating and liquid coating?

It is reported that currently, more than 90% of the coating in the domestic color coated board industry is still dominated by liquid coatings. The entire industry chain involves solvents or co solvents (with a solvent recovery rate of about 70% in China's coating industry in 2024), and hazardous waste is easily generated during production and use. In 2024, the hazardous waste production in the liquid coating industry reached 3.7 million tons, while the average utilization rate of liquid coatings in China was only 50% in 2024. Harmful substances can easily enter workers' bodies through the respiratory system or skin, causing occupational diseases.

Compared to liquid coatings, the production and use of powder coatings do not involve solvents or co solvents, and no "three wastes" are generated. The actual utilization rate of powder coatings is over 90%. Proper dust removal protection during production and use can ensure that there is no harm to the health of personnel in contact and the environment. The EU plans to promote the penetration rate of powder coatings market to 40% by 2030, while China's powder coatings account for less than 10% of the entire coating market share, which can be said to have great room for improvement.

From the perspective of coating performance, the cost of achieving 0T bending for liquid coatings is relatively high. The highest requirement for liquid coatings in HG/T 3830 2022 is 1T (for high processing household appliances), and there is no requirement for low-temperature T-bending and backlash.

Powder coating is easy to achieve 0T bending, which is convenient for later processing. The minimum requirement for powder coatings in HG/T 3830 2022 is 1T, with low-temperature (-20 ℃) T-bend and recoil requirements of 90kg.cm.

From the perspective of corrosion resistance, liquid coatings generally have a thickness of around 20 μ m, and the coating's resistance to penetration is relatively insufficient.

In addition, during the film formation of liquid coatings, the slow release of solvents may form "micro nano channels", which further affect the anti permeation ability of the coating film. Under the current limitations of coating thickness and construction process conditions, the corrosion resistance of liquid color coated boards is limited.

At present, the coating thickness of powder coated plates is generally 50-120 μ m, and the film-forming temperature is relatively high, generally above 220 ℃. In addition, there are no large amounts of solvent volatile compounds in the film-forming process, so the powder coating is relatively dense and has strong anti permeability ability.

In addition, liquid coated plate products on the market were also selected for comparison with their customers' powder coated plate products through additional accelerated corrosion tests, such as neutral salt spray tests and hydrochloric acid immersion tests. The finished boards before and after T-bending were compared, and the experimental results showed that the corrosion resistance of powder coated boards was significantly better than that of liquid coated boards.

From the comparison of the above data, it can be seen that in the field of color coated board applications, the comprehensive performance and cost-effectiveness of powder coatings are much higher than those of liquid coatings, which brings huge performance guarantees and market space for the high-quality development of the powder coating industry.