Production of Prepainted Galvanized Steel Coils (PPGI)

Prepainted Galvanized Steel Coils (PPGI) is color coated steel. PPGI refers to factory zinc coated steel, where the steel is painted before forming, as opposed to post painting which occurs after forming. Other industry names for this product type include pre-coated steel, coil coated steel, color coated steel etc., all typically with a hot dip zinc coated steel substrate.

The term is an extension of GI which is a traditional abbreviation for Galvanized Iron. Today the term GI typically refers to essentially pure zinc (>99%) continuously hot dip coated steel, as opposed to batch dip processes.

The hot dip metallic coating process is also used to manufacture steel sheet and coil with a coating of aluminium or an alloy coating of zinc/aluminium, zinc/iron and zinc/aluminium/magnesium, all of which may also be factory pre-painted. While GI is sometimes used as a collective term for various hot dip metallic coated steels, it more precisely refers only to zinc coated steel. Similarly, PPGI may sometimes be used as a general term for a range of metallic coated steels that have been pre-painted, but refers more precisely to pre-painted zinc coated steel.

Zinc coated steel substrate for PPGI is typically produced on a continuous galvanizing line (CGL). The CGL may include a painting section after the hot dip galvanising section, or more commonly, the metallic coated substrate in coil form is processed on a separate continuous paint line (CPL). Metallic coated steel is cleaned and pre-treated before the application of various organic coating layers which can be paints, vinyl dispersions or even laminates. The continuous process used to apply these coatings is often referred to as Coil Coating.

The steel product which is produced during this process is a pre-painted, prefinished and ready to use for further processing into finished products or components.

PPGI steel coils are commonly used for making building material such as roofing sheets, roofing tiles, sandwich panels, etc. The transportation, manufacturing industry, light industry, manufacture of office furniture, and manufacture of household electrical appliances are some other product areas which make use of PPGI steel coils.

China, South Korea and Taiwan are the top 3 producers of PPGI steel according to the global marketplace.

SOURCE: https://en.wikipedia.org/wiki/PPGI