news — from the mill.
Production notes, industry updates, and a little colour on what we’re making this month.
PPGI Coastal Corrosion: Specifying Coil Near the Sea
For a building within a few kilometres of the sea, the short answer is: do not buy a standard inland PPGI specification. Specify a heavier zinc mass on the substrate (commonly Z275 or higher, or a zinc-aluminium coating where the contract allows), a paint system with proven salt-spray and UV performance, full cut-edge protection, and […]
Read →PPGI Chalk and Fade Under UV: How to Specify for High-UV Roofs
How long a PPGI roof keeps its colour in strong sunlight depends on the whole coating build-up, not on one additive. In practice, a well-specified polyester system on a properly pretreated, zinc or zinc-alloy coated substrate may hold appearance for years in a temperate climate, while the same paint on a thin metallic coating, a […]
Read →PPGI Blistering and Cratering Defect Analysis
Small blisters, craters and pinholes in the paint film of a prepainted galvanized (PPGI) coil are usually a coating-process problem, not a steel problem — but they are not all the same defect, and they do not all have the same answer. Blisters are raised, closed bubbles under the film; craters are shallow, open depressions […]
Read →PPGI Paint Peeling Causes and How to Find the Real One
If the paint is flaking off your PPGI panels, the honest answer is that it is usually not one single defect. It is either a material condition (pretreatment residue, under-cured coating, contaminated zinc surface) or damage introduced during slitting, roll forming, fastening and site handling. In most complaints we see described, the failure is a […]
Read →PPGI Color Difference Causes: Batch to Batch Control
If your second PPGI batch does not match the first, the cause is almost always a change in one of five variables: pigment or tinting paste lot, paint line speed and oven temperature, primer shade, substrate colour, or the measurement method used to judge the difference. Colour is not a single property of a coil […]
Read →PPGI Trading Company vs Direct Manufacturer Risks
It is not automatically safer to buy prepainted galvanized (PPGI) coil from a manufacturer, nor automatically riskier to buy from a trading company. Safety comes from knowing who physically controls the coating line, the paint kitchen and the final inspection, and from matching that reality to your order. A trader can be the better partner […]
Read →PPGI Supplier Qualification Checklist for a First Order
Before placing a first order, verify a PPGI manufacturer in seven areas: production line capability and width/thickness range, paint line type and curing control, substrate sourcing and traceability, in-house testing lab and equipment, reference projects you can actually check, documentation habits, and a trial-order design that tests the exact risks you care about. Treat marketing […]
Read →PPGI quotation inputs cost drivers explained
Two suppliers can quote the same nominal PPGI specification and still land far apart, because a quotation is not one price — it is a stack of cost drivers. The main inputs that move a prepainted galvanized coil quotation are substrate grade, zinc mass, paint system, coating thickness, coil weight, dimensional tolerance, packaging and order […]
Read →PPGI Backcoat Specification: Function and Thickness Guide
Yes — the back side coating of PPGI coil matters, and it is one of the most frequently under-specified items on a purchase order. For most exposed roofing profiles, a nominal 5 µm polyester backcoat is adequate because the reverse side is mainly a handling and corrosion-barrier surface. For sandwich panel facing — especially where the […]
Read →PPGI Paint Coating Thickness: Primer, Topcoat, Backcoat
A single “20 microns total paint” figure is not enough to judge a prepainted galvanized steel (PPGI) specification. It tells you the combined dry film thickness (DFT) of all paint layers, but it does not tell you how that film is divided between primer, topcoat and backcoat, which resin systems are used, or how the […]
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