What Is Prepainted Galvanized Steel Coil
[edit] Introduction
Prepainted galvanized steel coil is a kind of colour coated steel coil (PPGI coil). It uses galvanized steel as the base metal. The zinc layer offers strong corrosion resistance. Plus with painting, it is more durable than galvanized steel.The metallic coated steel then experiences some cleaning procedures, pre-treatment solutions and ultimately gets multiple layers of organic coatings, including laminates, vinyl dispersions, and paint. This continuous technique of applying different coatings is referred to as coil coating. Therefore, the steel coil doesnt require painting or finishing when employed in finished products.
[edit] PPGI vs. PPGL
To start with, they use different substrates. PPGI uses galvanized sheets as being the base metal. They have a zinc coating throughout to prevent moisture, rust, and corrosion from destroying the steels surface.The substrate for prepainted galvalume steel is a combination of 1.6% silicon, 43.3% zinc, and 55% aluminum. The substrate influences their applications which further differentiates the 2 kinds of steel.
The service life of these two types of steel also varies because of the substrates. The substrates prolong the steels service life by protecting them from rust and corrosion. Zinc is the perfect substrate for safeguarding steel from rust. PPGI has near to 99% zinc within its substrate, but PPGL only has 43.3%. This gives PPGI a longer service life in comparison with PPGL. Although aluminum and silicone are great alloys, they arent the best at protecting steel from corrosion or rust. They eventually wear out with time, thus exposing the steel to moisture that leads to corrosion.
There is also a difference between the weight of PPGI and PPGL. Aluminum, zinc, and silicone substrates are heavier than zinc substrates. As a result PPGL is heavier than PPGI. However, many industries prefer PPGI due to its ability to withstand rust and corrosion. The strength of the steel is more or less similar to PPGL. A PPGL sheet covers around 3% extra space compared to a PPGI sheet.
[edit] Related articles on Designing Buildings
Featured articles and news
National Apprenticeship Week 2026, 9-15 Feb
Shining a light on the positive impacts for businesses their apprentices and the wider economy alike.
Applications and benefits of acoustic flooring
From commercial to retail.
From solid to sprung and ribbed to raised.
Strengthening industry collaboration in Hong Kong
Hong Kong Institute of Construction and The Chartered Institute of Building sign Memorandum of Understanding.
A detailed description fron the experts at Cornish Lime.
IHBC planning for growth with corporate plan development
Grow with the Institute by volunteering and CP25 consultation.
Connecting ambition and action for designers and specifiers.
Electrical skills gap deepens as apprenticeship starts fall despite surging demand says ECA.
Built environment bodies deepen joint action on EDI
B.E.Inclusive initiative agree next phase of joint equity, diversity and inclusion (EDI) action plan.
Recognising culture as key to sustainable economic growth
Creative UK Provocation paper: Culture as Growth Infrastructure.
Futurebuild and UK Construction Week London Unite
Creating the UK’s Built Environment Super Event and over 25 other key partnerships.
Welsh and Scottish 2026 elections
Manifestos for the built environment for upcoming same May day elections.
Advancing BIM education with a competency framework
“We don’t need people who can just draw in 3D. We need people who can think in data.”
Guidance notes to prepare for April ERA changes
From the Electrical Contractors' Association Employee Relations team.
Significant changes to be seen from the new ERA in 2026 and 2027, starting on 6 April 2026.
First aid in the modern workplace with St John Ambulance.
Solar panels, pitched roofs and risk of fire spread
60% increase in solar panel fires prompts tests and installation warnings.
Modernising heat networks with Heat interface unit
Why HIUs hold the key to efficiency upgrades.