In the field of metal sheet processing and decoration, printed color coated plates are sparking an innovative revolution with their unique charm and excellent performance. As a composite material based on metal coils, coated with organic coatings or plastic films on the surface, and endowed with diverse patterns and colors through advanced printing technology, printed color coated plates not only break through the color limitations of traditional color boards, but also achieve a qualitative leap in decoration and functionality, becoming a new favorite in industries such as construction, home appliances, and automobiles.

1. Composition and classification of printed color coated plates

1. Substrate selection

The main substrates for printed color coated plates are cold-rolled steel plates, galvanized steel plates, and aluminum plates. Among them, cold-rolled steel plates are commonly used for building exterior walls due to their low cost and high strength; Aluminum plates have become the preferred choice for high-end home appliances and transportation vehicles due to their lightweight and corrosion-resistant properties. The thickness of the substrate is usually between 0.3-2.0mm, and it needs to undergo flatness treatment to ensure coating adhesion.

2. Coating system

The coating system consists of primer, intermediate coat, topcoat, and clear coat (optional), forming a multi-layer protective structure:
(1) Primer: Made of epoxy resin or polyester resin, its main function is to enhance the adhesion between the coating and the substrate, while providing rust prevention performance.
(2) Mid coat: mainly made of polyester resin, filling small defects on the surface of the substrate to improve the smoothness of the coating.
(3) Topcoat: It is divided into polyester type, fluorocarbon type, and silicon modified polyester type, which determine the color, gloss, and weather resistance of the coating. For example, the UV resistance of fluorocarbon topcoat can last for more than 20 years.

(4) Clear varnish: optional, used to enhance the glossiness and scratch resistance of coatings.

3. Color implementation method

The color of printed color coated plates can be achieved in two ways:
(1) Pre coating process: The color paint is directly applied to the substrate through roller coating, spray coating or printing technology in the factory, with high color uniformity and suitable for large-scale production.

(2) Post printing process: Based on the pre coated whiteboard, personalized customization is achieved by overlaying patterns through screen printing, digital printing, or heat transfer printing technology. This is commonly used in home appliance panels and advertising signs.

2. Core manufacturing process

1. Preprocessing stage

The substrate needs to undergo processes such as degreasing, acid washing, phosphating, etc. to remove surface oil stains and oxide layers, form a phosphate conversion film, and enhance coating adhesion. For example, galvanized steel plates need to use chromium free phosphating solution to meet environmental requirements.

2. Coating construction

(1) Roller coating method: The coating is evenly applied to the substrate through multiple sets of rollers, which is suitable for continuous production and has high controllability of coating thickness.
(2) Spraying method: using electrostatic spraying technology, the coating utilization rate reaches over 90%, suitable for complex shaped substrates.

(3) Printing method: Combining UV curing technology to achieve high-precision pattern transfer, with a resolution of up to 1200dpi.

3. Curing and Forming

The coating needs to be cured in an oven at 200-250 ℃ for 10-15 minutes to crosslink the resin and form a dense film layer. After curing, the coating should be formed through stamping, bending and other processes to ensure that there is no cracking or peeling of the coating.

3. Performance advantages and application areas

1. Weather resistance and corrosion resistance

The salt spray resistance test of fluorocarbon coated board can reach more than 5000 hours, suitable for coastal or highly polluted environments. Polyester coated boards can extend their outdoor service life to 10-15 years by adding UV absorbers.

2. Decorative and functional aspects

Printed color coated plates can simulate textures such as metal wire drawing, wood grain, stone grain, etc., meeting the personalized needs of architectural decoration. Meanwhile, by adding antibacterial agents or self-cleaning coatings, its applications in the medical and food processing fields can be expanded.

3. Environmental Protection and Sustainability

Modern printed color coated plates use water-based coatings and solvent-free processes, reducing VOC emissions by over 80% compared to traditional solvent based coatings. Waste can be recycled and reused, meeting the requirements of circular economy.
Looking ahead to the future, the development prospects of printed color coated plates are highly anticipated. With the continuous innovation of technology and the upgrading of market demand, it will surely shine in more fields and bring more surprises to the industry. Enterprises also need to keep up with the pace of the times, increase research and development investment, drive development with innovation, and jointly promote the printing color coated board industry towards a more brilliant tomorrow.