1.What are the procedures and steps in the first stage?
Uncoiler: Typically uses a double uncoiler configuration to allow for non-stop coil changing, ensuring continuous production.
Sewing Machine: Welds the ends of two coils of steel strip together, ensuring uninterrupted operation of the production line.
Inlet Loop: Stores a large quantity of steel strip, continuously supplying material to subsequent process sections during uncoiling, changing, or sewing, and is crucial for ensuring high-speed operation of the production line.
2.How to perform preprocessing?
The purpose of this stage is to clean the substrate (cold-rolled steel, galvanized steel, zinc-coated steel, etc.) and provide good coating adhesion and corrosion resistance.
Cleaning Section Equipment: Includes tanks and spray systems for alkaline spraying, brushing, and rinsing.
Removes grease, dust, and impurities from the steel strip surface.
Chemical Coating Section (Chemical Coating Machine): A thin, uniform chemical conversion coating (such as chromate or chromium-free treatment agent) is applied to the cleaned steel strip surface using a roller coating method.
Main equipment includes: chemical coating roller coater and dryer (usually a hot air circulating type).
3.What are the coating and curing process steps?
Primer/Finish Roller Coator:
* The core of the system. Typically a two-coat, two-bake system (primer coating + curing, topcoat coating + curing).
* The equipment includes: coating rollers, feed rollers, metering rollers, and backing rollers. Precise control of wet film thickness is achieved through precise adjustment of roller pressure and speed.
* Equipped with automatic viscosity control and a paint circulation system.
Curing Oven:
* The coated steel strip immediately enters a long curing oven. The oven is divided into multiple temperature zones for programmed heating.
* Hot air circulation convection heating or radiant heating (such as infrared) is used to evaporate the solvent in the coating and allow the resin to undergo a cross-linking reaction for complete curing.
* Oven temperature control precision is crucial, directly affecting the coating's hardness, flexibility, and durability.
4.How to perform post-processing and finishing?
Laminating machine (film laminating machine): Used to produce laminated color-coated steel sheets. It applies PVC or PET film to the surface of the color-coated steel sheet under high temperature and pressure, providing better weather resistance and decorative properties.
Embossing machine: Uses patterned rollers to emboss three-dimensional textures such as wood grain and leather texture while the coating is not completely cooled.
Cooling section: The cured steel strip passes through an air-cooling or water-cooling section to cool to a suitable temperature.
Tension straightening machine: Eliminates waviness and warping of the steel strip, ensuring a flat sheet shape.
5.What are auxiliary and public systems?
Paint supply and circulation system: Includes paint tanks, pumps, pipelines, filters, and paint mixing room.
Resource-to-Oil (RTO/TO) system: Treats volatile organic compound (VOC) waste gas emitted from the curing oven, meeting environmental protection requirements and recovering heat energy.
Central control system (DCS/PLC): Integrates automated control, monitoring all parameters such as speed, tension, and temperature throughout the entire production line.
Compressed air system, hydraulic system, cooling water system, etc.