PPGI means pre-painted galvanized steel while PPGL describes pre-painted galvalume steel.

• Basic composition and use

PPGI sheets are processed by coating with molten zinc. The zinc coating is a base metal that has protective properties making this type of sheet ideal and popular for roofing. It can also be used to produce outdoor billboards, washing machines, etc. PPGI sheets are not easily corroded and so can withstand strong sun and rain.

PPGL sheets are processed by coating with zinc, silicon, and aluminium. More precisely, the ingredients of the galvalume steel sheet have at least 55% aluminium and 43.5% zinc, with the rest being silicon and other elements. PPGL sheets can be used as roofing in addition to chimney pipes or ovens owing to their corrosion resistance, good heat resistance, and surface conductivity.

Differences Between PPGI And PPGL Sheets

PPGI means pre-painted galvanized steel while PPGL describes pre-painted galvalume steel. Below is a list of differences between PPGI and PPGL.

Basic composition and use

• Durability

PPGI sheets that are galvanized with 100% zinc perform poorly compared to PPGL sheets when exposed to natural influences such as water. PPGL sheets may last beyond 10 years in good condition. They do not easily rust and do well when in contact with liquids that go through an oxidation process.

The lifespan of PPGL is almost double that of PPGI.

• Thickness and weight

Generally, PPGI sheets are lighter than PPGL sheets. The thickness however is dependent on the coating applied.

• Corrosion resistance

PPGL sheets are more corrosion resistant. When a PPGL sheet is cut, its edges become exposed which makes it more vulnerable to corrosion.

PPGI on the other hand is quite likely to become corroded. When corrosion happens, it is localised and less likely to spread through the whole sheet.

PPGL sheets possess a smoother finish in comparison with PPGI sheets which can be directly caused by the aluminum component in PPGL which PPGI sheets do not have. This makes it much easier to paint PPGL sheets without pre-treating them, although this is not advisable.