The Use, Processing, and Installation of Pre-painted Steel Sheets

The Use, Processing, and Installation of Pre-painted Steel Sheets

1. The mechanical properties (such as yield strength and elongation) and coating properties (including pencil hardness, T-bend value, and impact energy) of pre-painted steel sheets typically change with extended storage time, which can affect the forming process. Therefore, it is generally advised to process and use them within one year.

2. To prevent excessive deformation during single-step forming that may damage the adhesion of the coating, complex-shaped parts should undergo multi-stage forming with reduced deformation per stage. The processing speed, appropriate gaps considering the coating thickness, and other factors like equipment condition and part design should be set reasonably. Low temperatures can impair the flexibility of the coating; hence, cold processing should be avoided.

3. Most coatings can serve as lubricants sufficient for various forming processes. If additional lubrication is needed, methods such as oiling, wax application, or using a peelable protective film can be employed. However, it’s crucial to note that wet lubricants can attract contaminants that should be removed before installation, and peelable films should be promptly taken off after processing.

4. Ensure the cleanliness and integrity of processing equipment to prevent coating damage. Metal particles produced during cutting should be promptly cleared to minimize wear on forming rolls and模具 surfaces. Cutting tools must be sharp, and burrs should not be present on the blades.

5. Cut edges and punctured surfaces are prone to corrosion, so when cutting or punching, minimize burrs, and, if possible, design cuts or holes in inconspicuous areas or apply protective coatings or sealing strips to processed edges.

6. Prior to installation, inspect the color and surface quality of the pre-painted sheets. If the coating has been damaged during previous processing, use caution. During installation, avoid dragging, scratching, or scuffing the coating, and prevent bending or indentation. Workers should wear smooth-soled shoes without debris like pebbles or metal shavings, distribute their weight evenly, and be mindful of their footsteps to prevent sheet deformation.

7. When connecting pre-painted sheet parts with fasteners like screws or rivets, ensure their corrosion resistance matches that of the pre-painted sheet to avoid premature corrosion, which could become a corrosion source. Also, consider the galvanic potential difference between the fastener material and the pre-painted sheet to prevent galvanic corrosion; zinc-coated or aluminum fasteners are recommended. Use installation tools carefully to avoid damaging the sheets. Position fasteners judiciously, and tighten screws to an appropriate level to prevent leaks from overtightening or deformation from being too loose.

8. When using adhesives, sealants, or other chemicals, ensure they are neutral to avoid acidic or alkaline substances that could corrode the coating and reduce the lifespan of the pre-painted sheets.

9. Pay attention to the installation angles and positions of pre-painted sheet components. Prolonged water retention reduces coating adhesion, so designs should allow for water drainage to prevent pooling. Copper, lead, graphite, and uncoated steel, as well as raw wood, undried lumber, or wet cement, should not come into direct contact with pre-painted sheets as they can react with the base metal or coating, shortening the sheets’ service life.