PPGI Specifications & Quality Standards
SRK Steel supplies Pre-Painted Galvanized Steel (PPGI) Coils and Sheets manufactured and tested according to applicable international standards and customer specifications.
Quality inspection can include mechanical, dimensional, metallic-coating and paint-performance tests at the manufacturing or processing stage, depending on the required specification and application.
Typical Quality Tests
- Coating thickness / zinc coating test
- Paint coating thickness test
- Adhesion test
- Pencil hardness test
- Impact resistance test
- T-bend test
- Gloss measurement
- Surface finish and appearance inspection
- Tensile strength and elongation
- Dimensional and thickness inspection
SRK Steel – PPGI Coil & Sheet Supplier in UAE and GCC, supplying pre-painted galvanized steel for roofing, wall cladding, sandwich panels, industrial buildings and general fabrication.
PPGI Coil Quality & Paint Testing Standards – ASTM Tests
PPGI (Pre-Painted Galvanized Steel) coils and sheets are subjected to coating, paint and performance tests to verify colour accuracy, coating thickness, adhesion, flexibility, hardness, gloss, solvent resistance and corrosion resistance. The following ASTM test methods are commonly referenced for quality evaluation of pre-painted galvanized steel products.
Test-method editions shown in the table should be confirmed against the customer specification, project requirements and the current applicable test standard before contractual use.
| Test / Quality Parameter | ASTM Standard | What It Evaluates |
|---|---|---|
| Colour Difference / Colour Matching | ASTM D2244-16 | Measures colour difference and verifies colour consistency of PPGI coating against the specified reference colour. |
| Salt Spray / Corrosion Resistance | ASTM B117-18 | Evaluates the resistance of the painted steel coating to salt spray and accelerated corrosive environments. |
| Pencil Hardness | ASTM D3363-05(2011)e2 | Determines the surface hardness and scratch resistance of the paint coating. |
| T-Bend Test | ASTM D4145-10(2018) | Evaluates the flexibility and adhesion of the coating when the pre-painted galvanized steel is bent. |
| Dry Film Thickness (DFT) | ASTM D5796-10(2015) | Measures the thickness of the dry paint/coating film applied to the galvanized steel substrate. |
| Cross-Hatch Adhesion | ASTM D3359-17 | Determines the adhesion of the paint coating to the galvanized steel substrate. |
| Solvent Resistance | ASTM D5402-19 | Evaluates the resistance of the organic coating to solvent exposure and coating degradation. |
| Specular Gloss | ASTM D523-14(2018) | Measures the gloss level and surface appearance of the PPGI coating. |
| Mandrel Bend Test | ASTM D522-17 | Evaluates coating flexibility, cracking and adhesion after bending around a specified mandrel. |
| Chalk Resistance | ASTM D4214-07(2015) | Evaluates the tendency of an exterior paint coating to develop chalking after weathering exposure. |
Differences between RMP and PVDF Paints
| PPGI Coating System – RMP vs PVDF | ||
|---|---|---|
| Property / Test | RMP – Modified Polyester | PVDF – Polyvinylidene Fluoride |
| Resin System | Polyester & Melamine | Polyvinylidene Fluoride & Acrylic |
| Film Formation | Cross-linking | Fusion |
| Peak Metal Temperature (PMT) | 224–235°C | 249–254°C |
| Primer Type & Thickness | Polyurethane / Polyester Primer: 4–6 μm | Polyurethane Primer: 5–7 μm |
| Topcoat Thickness | 18–20 μm | 20–22 μm |
| MEK Double Rub | 100 D/R – Pass | |
| T-Bend | 2–3T | 0–1T |
| Reverse Impact | 13 J – No paint removal | |
| Cross-Hatch Adhesion | No paint removal | |
| Pencil Hardness | F minimum | B minimum |
| Water Boil Adhesion | Pass | |
| Accelerated Weathering & Corrosion Performance | ||
| Performance Test | RMP – Modified Polyester | PVDF – Polyvinylidene Fluoride |
| Humidity Resistance – HDG | No blistering, peeling, cracking, significant loss of gloss or softening after 1,000 hours at 100% RH and approximately 38°C | No blistering, peeling, cracking, significant loss of gloss or softening up to 2,000 hours at 100% RH and approximately 38°C |
| QUV – UV Exposure | QUV-A: 4 h UV at 75°C + 4 h condensation at 50°C; up to 1,000 UV hours | QUV-B: 4 h UV at 50°C + 4 h condensation at 40°C; up to 1,000 UV hours |
| Color Change | ≤5 NBS units, as specified | |
| Chalking | ≤ Rating 2 | |
| Gloss Retention | As specified by applicable test method | |
| Blistering / Adhesion Loss | No blistering or adhesion loss after specified exposure | |
| Salt Spray Resistance – HDG | No blistering after 1,000 hours in 5% neutral salt spray | No blistering after 2,000 hours in 5% neutral salt spray |
| Chemical Resistance | ||
| Chemical Test | RMP – Modified Polyester | PVDF – Polyvinylidene Fluoride |
| 10% HCl – 30 min Spot Test | No significant color change or blistering | |
| 5% NaOH – 30 min Exposure | No significant color change or blistering | |
| Durability & Chalk Retention | ||
| Property | RMP – Modified Polyester | PVDF – Polyvinylidene Fluoride |
| Film Integrity – Reference Period | 10 years | 20 years |
| Chalk Retention – ASTM D4214, Method A | Rating >2 | Rating >4 |
Standard Colour Range
| Colour | RAL Code |
|---|---|
| Grey White | RAL 9002 |
| Light Ivory | RAL 1015 |
| Leaf Green | RAL 6002 |
| Light Grey | RAL 7035 |
| Beige | RAL 1001 |
| Ivory | RAL 1014 |
| Reseda Green | RAL 6011 |
| Sky Blue | RAL 5015 |
| Light Blue | RAL 5012 |
| Signal Red | RAL 3001 |
| As per Customer Samples | Custom |
Quality Assurance
| Test | Range / Specification |
|---|---|
| Erichsen Cupping Test | 7.0 mm |
| T-Bend Test | 0T – 4T |
| Impact Test | 70 kg·cm to 100 kg·cm |
| Pencil Hardness | F – H – 2H |
| Scratch Resistance | 1 to 1.5 kg |
| Solvent Resistance (MEK) | 100 rubs (Double Rubs) |
| Gloss at 60° | 20–90% |
| Colour Difference from Standard | < 1.0 for lighter colour; < 1.5 for darker colour |
| Visual Colour Comparator | At different light sources |
| Humidity Resistance | 1000 hours |
| Salt Spray Test | 750 to 1000 hours |
Quality assurance can include source-mill or processor inspection, dimensional checks, coating and paint test reports, and agreed technical documentation such as MTC/COC records where applicable.
Note: The grades and tolerances shown are indicative. Special grades and closer tolerances can be discussed case by case and agreed before order confirmation.
| Applications | International Specifications: Euro Norm | International Specifications: American Standards | International Specifications: JIS Standards | Substrate | Coating | Dimension Range (mm) | Indian Specification Standards |
|---|---|---|---|---|---|---|---|
| General fabrication | EN 10169 | ASTM A 755 | JIS - G3312 | Galvanized (90 - 275 GSM) Cold rolled / Aluminium | Primer 4-8 micron, Top Coat 14-30 micron, Back Coat 5-10 micron | Thickness: 0.25 to 1.20 Width : 100 to 1350 | IS 14246 |
| Roofing | EN 10169 | ASTM A 755 | JIS - G3312 | Galvanized (90 - 275 GSM) Cold rolled / Aluminium | Primer 4-8 micron, Top Coat 14-30 micron, Back Coat 5-10 micron | Thickness: 0.25 to 1.20 Width : 700 to 1350 | IS 14246 |
| Profiling | EN 10169 | ASTM A 755 | JIS - G3312 | Galvanized (90 - 275 GSM) Cold rolled Y.S-240/340/550 MPa | Zinc coating wt. 90-275 GSM Primer 4-8 micron both sides Top Coat 14-30 micron, Back Coat 5-10 micron Optional guard film can be supplied | Thickness: 0.20 to 0.80 Cover Width : 1060/1200 (before profiling) 1220/1370 Length: 12000mm Max | IS 14246 |
Applications of PPGI & PPGL Coils
PPGI (Pre-Painted Galvanized Steel) and PPGL (Pre-Painted Aluzinc/Aluminium-Zinc Steel) coils are widely used across the UAE and GCC for construction, roofing, cladding and industrial manufacturing. Their factory-applied colour coating provides an attractive finish, corrosion protection and consistent surface quality.
Key Applications
Roofing & Wall Cladding
Sandwich Panel Manufacturing
Industrial & Commercial Buildings
Cold Rooms & Refrigeration Panels
HVAC & Air-Conditioning Equipment
Fencing & Metal Panels
Garage Doors & Rolling Shutters
Ceiling & Interior Partition Systems
Steel Furniture & Cabinets
Home Appliances & White Goods
Agricultural Buildings, Greenhouses & Sheds
Architectural & Decorative Cladding
PPGI and PPGL coils are available in multiple thicknesses, widths, coating specifications and RAL colours, making them suitable for roll forming, profiling, fabrication and panel manufacturing.
PPGI & PPGL Coils for GCC Applications
Suitable for projects and manufacturing customers across the UAE, Saudi Arabia, Qatar, Oman, Kuwait and Bahrain, with specifications selected according to the application, environmental exposure, coating system and required service performance.
