news — from the mill.
Production notes, industry updates, and a little colour on what we’re making this month.
PPGI Coil Slitting and Edge Trim Tolerances: RFQ Guide
Standard tolerances for PPGI coil width after slitting typically range from ±0.5 mm to ±2.0 mm, depending on strip thickness and width. Edge condition, including burr height, is normally specified at a maximum of 0.05 mm to 0.10 mm for painted steel. However, these values are general industry guidance, not universal guarantees. Your RFQ must […]
Read →Does Zinc Spangle Size Affect PPGI Coil Paint Appearance and Performance?
Yes, zinc spangle size can affect PPGI coil paint appearance, but its effect on performance is indirect and often overstated. The visible “spangle pattern” through paint is primarily a surface texture phenomenon, not a corrosion or coating failure. However, when spangles are excessively large or irregular, they can create a telegraphing effect—a visible grain or […]
Read →PPGI Coil Storage: Preventing Condensation, Scratches & Edge Damage
To keep PPGI coils in perfect condition, you must control three variables: temperature stability, physical isolation, and moisture exposure. Correct storage conditions require a dry, ventilated warehouse with a stable climate, while proper handling demands dedicated lifting equipment, protective packaging, and strict edge-protection protocols. This article explains how to implement those measures, troubleshoot common damage, […]
Read →PPGI Coil Color Consistency: Controlling Variation Across Batches
To prevent color variation between PPGI coils from the same order, manufacturers must control raw material inputs, maintain stable paint formulations, calibrate coating thickness and curing ovens, and implement a documented color-approval and batch-tracking protocol. Color consistency is not achieved by a single inspection step; it is engineered through process discipline across every production run. […]
Read →Selecting PPGI Roofing for Southeast Asia: Heat, Humidity, and Rain
The best PPGI coil for roofing in Southeast Asia combines a hot-dip metallic coating of at least AZ150 (aluminium-zinc) or Z275 (galvanized), a durable topcoat such as silicone-modified polyester (SMP) or polyvinylidene fluoride (PVDF), and a reverse side coating of at least 7–10 µm to withstand humidity. However, the optimal specification is not a universal […]
Read →White Rust and Condensation: How to Store PPGI Coils Properly
To prevent moisture damage like white rust, store PPGI coils indoors on a dry, level surface, off the ground, with breathable wrapping intact, and maintain a stable environment with low humidity and minimal temperature fluctuation. The key is controlling condensation—not just rain—because trapped moisture between wraps corrodes the zinc layer long before the coil reaches […]
Read →PPGI Coil Tolerances: Thickness, Width, and Flatness Standards
Your fabrication line stops. A forming die jams because the PPGI coil is 0.02 mm thicker than expected. This is the real cost of ignoring coil tolerances. Standard tolerances for PPGI coil thickness, width, and flatness are defined by international specifications such as ASTM, JIS, EN, and GB/T, but the exact values you must enforce […]
Read →PPGI Paint System Selection: PE, SMP, HDP, or PVDF
Choosing the right paint system for your PPGI coil is a technical decision that affects formability, color retention, and lifecycle cost. The four primary options—Polyester (PE), Silicon Modified Polyester (SMP), High Durability Polyester (HDP), and Polyvinylidene Fluoride (PVDF)—differ in resin chemistry, durability, and cost drivers. This guide explains how to match each paint system to […]
Read →
High-UV Climates: Choosing Between PPGI and Galvalume Coils
For a roofing project in a region with intense sun, the short answer is: you should generally choose a prepainted galvalume coil (PPGL) over a standard prepainted galvanized coil (PPGI) when the primary threat is UV radiation combined with high heat. However, the correct selection is not simply a matter of picking one over the […]
Read →PPGI Coating Thickness Measurement: Methods and Verification
To measure the total coating thickness on PPGI coils, you use magnetic induction or eddy current gauges that separately measure the metallic zinc layer and the paint film. The most reliable verification process combines a calibrated magnetic gauge for zinc on steel, a paint gauge using eddy current or ultrasonic principles, and cross-checking against the […]
Read →