news — from the mill.
Production notes, industry updates, and a little colour on what we’re making this month.
PPGI Total Landed Cost Factors Beyond FOB Price
To build a landed-cost comparison for PPGI coil imports that goes past the FOB number, convert every commercial and technical variable into a cost per usable tonne: add freight and insurance, adjust for actual versus nominal coil weight, price the tolerance you are buying, estimate damage and claim recovery, then add the cash and storage […]
Read →PPGI Coil RFQ Template: 14 Mandatory Fields
To get a comparable PPGI coil quotation from your first email, include fourteen fields: substrate and grade, zinc or zinc-alloy coating mass, paint system and topcoat thickness, total coating thickness, colour and RAL reference, surface finish and treatment, coil dimensions, coil weight and ID, tolerances, quantity and delivery schedule, packaging, destination and Incoterms, required standards […]
Read →How to Read a Prepainted Galvanized Steel Coil Specification
A complete PPGI coil specification should lock down six things: substrate grade and thickness, metallic coating type and mass, paint system chemistry and dry film thickness, dimensional tolerances, mechanical properties, and the test methods used to verify each one. If any of those six is missing, vague, or stated only as a “typical value,” a […]
Read →PPGI Zinc Coating Mass: Z100, Z180 or Z275 by Environment
Yes — the zinc coating mass under the paint still matters, and in most projects it is the single largest determinant of how long a prepainted coil resists corrosion once the paint film is breached. Paint protects the surface; zinc protects the steel. A scratched, cut, drilled or folded edge exposes bare metal, and from […]
Read →PPGI Coil Substrate Grade Selection: DX51D, S250GD, S350GD
If your prepainted coil will be roll formed into a load-bearing roofing or cladding profile, choose a structural substrate grade such as S250GD or S350GD rather than DX51D. If the part is a flat or lightly formed panel where stiffness comes from the profile shape and the fixing system, DX51D is usually adequate. The reason […]
Read →PPGI Coating Spec: Microns vs GSM Explained
You convert coating weight (g/m², often written gsm) to dry film thickness (µm) by dividing the coating weight by the coating’s density, then multiplying by 1,000: µm = (g/m² ÷ density in g/cm³) × 1,000. For most polyester topcoats a density of roughly 1.2–1.5 g/cm³ is a reasonable planning figure, which puts a 20 µm […]
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PPGL Galvalume Substrate Paint Adhesion Requirements
Paint adhesion on PPGL is not automatically weaker than on PPGI, but it is less forgiving. The Al-Zn (55% aluminium, 43.4% zinc, 1.6% silicon by typical nominal composition) surface behaves differently from a pure zinc coating: it forms a thin, stable aluminium oxide that resists the very chemical bonds a paint film needs, and it […]
Read →PPGI Bending and Profiling Limits: T-Bend Test Guide
There is no single minimum bend radius that applies to all prepainted galvanized (PPGI) coil. The safe radius for your coil depends on the paint system, the substrate thickness and tensile properties, the metallic coating, the bend direction relative to the coil, and the forming method. The practical way to answer “will my coating survive […]
Read →PPGI Roofing Sheet Roll Forming Line Setup Guide
To roll form prepainted galvanized steel without damaging the coating, start with a forming speed low enough to keep the strip cool and the line stable (commonly a fraction of what you would run on bare galvanized), set roll gaps so the paint is never pinched or squeezed, and use a lubricant that is compatible […]
Read →PPGI Cut Edge Corrosion: Mechanism and Mitigation
Rust along cut edges and drilled holes after a couple of years is common but not inevitable. A cut edge of prepainted steel is bare metal: the paint film stops, and the only remaining protection is the metallic coating on the substrate, usually zinc. Zinc protects the exposed steel sacrificially, but that protection is finite […]
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