The color coating line is located along the galvanizing line and has been designed in the form of roller coating. Among the advantages of this line is its high speed, low paint consumption, and environment friendliness.
In this process, the galvanized or cold-rolled coil is first skin passed in the cold rolling mill, and enters the sheet preparation section, where it is sprayed with a degreasing solution on both top and bottom surface of the sheet.
Then special rotary brushes brush both surfaces of the sheet. The process is repeated again and the sheet dries in a stream of hot air blown onto it after it has been cleansed in water. At the end of this stage, a suitable chemical is applied on both surfaces of the sheet and the sheet is dried in a suitable temperature. This prevents the paint coating from scaling off in the later forming stages. The sheet later arrives in the coating section for the application of paint on it.
In this section, first a layer of the initial paint (primer) of polyester and back coat is applied on the sheet upper and bottom surface respectively and the color coated sheet enters the furnace for the paint to be cured. After complete curing, the sheet is cooled down and a final layer of polyester, poly vinyl iodine fluoride, epoxy, polyvinyl chloride and polyurethane is applied on the surface of the sheet by rollers and then the paint is cured again.
The use of high thickness of plastisol paints on the upper surface of the sheet allows the creation of special texture designs in the form of leather, cotton, granite and so forth on the upper surface of the sheet with Embosser unit which is located after the final paint curing furnace.
This product is of high corrosion resistance and excellent formability. The product will then undergo meticulous quality control procedures and is stuck with a protective layer of polyethylene or polypropylene on the surface and sent to the market after it has been packaged. It is also possible to apply a protective lay
er of PET or PVC on the sheet surface as the final protective layer using a Laminator unit. This type of sheet is used for the manufacture of home appliances such as refrigerator and freezer doors.
Major applications of color-coated (prepainted) sheets:
Structural: such as roofing and siding of the storehouses and workshops, false ceilings, inner and outer façades of the buildings.
Home appliances: outer shell of the refrigerators, water heaters, stoves, washing machines, etc.
Metallic industries: cabinets, office tools, partitions, computer cases, etc.
Transportation industry: containers, cold-houses, stationary and mobile containers, etc.