How PPGI and PPGL Coils Are Manufactured

Industries today demand steel products that combine durability, versatility, and attractive design. PPGI (Pre-Painted Galvanized Iron) and PPGL (Pre-Painted Galvalume) coils meet these needs by blending strong steel bases with advanced coatings. Manufacturers apply protective layers of zinc or aluminum-zinc, followed by high-quality paint systems. As a result, the coils resist corrosion, maintain stability under heat, and offer a wide range of colors for modern applications.

How PPGI and PPGL Coils Are Manufactured

The production of pre-painted steel coils includes several clear stages:

1. Base Metal Preparation
   Producers choose galvanized steel for PPGI and Galvalume steel for PPGL. Each sheet passes inspection to confirm surface quality and uniform thickness.

2. Cleaning and Pre-Treatment
   Workers clean the steel surfaces with chemical treatments that remove oils and dust. This preparation ensures strong paint adhesion.

3. Primer Coating
   Technicians apply a primer layer on both sides of the sheet. This layer improves corrosion resistance and bonds with the topcoat.

4. Topcoat Application
   Engineers apply a topcoat of polyester, SMP, or PVDF paint to the visible surface. The topcoat usually measures 10–25 microns and gives the coil its final color and finish.

5. Backcoat Application
   The back side receives a thinner paint layer, usually 5–12 microns, which adds extra protection during forming and use.

6. Curing and Baking
   The coils move through an oven where high heat cures the paint layers. This process locks in durability and smoothness.

7. Cooling and Rolling
   Finally, manufacturers cool the coils and roll them into customer-specific widths and lengths. Quality teams check every coil before delivery.

PPGI vs. PPGL – What Is the Difference?

Although both materials belong to the pre-painted steel family, their difference lies in the base coating.

• PPGI (Pre-Painted Galvanized Iron)
  Engineers use zinc-coated steel as the base. Zinc acts as a sacrificial layer, which slows rusting and protects the sheet. PPGI performs well in many environments but may wear faster in highly humid or coastal areas.

• PPGL (Pre-Painted Galvalume)
  Producers use aluminum-zinc coated steel. Aluminum forms a barrier against corrosion, while zinc protects cut edges. PPGL lasts two to three times longer than PPGI in harsh outdoor or coastal conditions.

In short, PPGI offers an economical solution, while PPGL delivers premium durability where the environment is demanding.

Technical Specifications

• Standards: ASTM A653M, EN 10346, JIS G3321, ASTM A792M

• Zinc/Al-Zn Coating: Z30–Z350 for PPGI; AZ30–AZ250 for PPGL

• Painting Thickness: Top side 10–25 microns, back side 5–12 microns

• Steel Grades: DX51D, DX52D, DX53D, SGC340, SGC400

• Thickness Range: 0.12–2.5 mm

• Width Options: 1000–1250 mm or customized

• Color Options: RAL chart or tailored to customer request

Applications of PPGI and PPGL Coils

1. Roofing and Wall Cladding
   Builders install PPGI and PPGL sheets in residential, commercial, and industrial projects. The sheets protect structures from rain, wind, and heat while offering modern colors.

2. Rolling Shutter Doors and Kiosks
   Manufacturers use these coils to make shutters, kiosks, and shopfronts. The strong paint finish ensures both security and an attractive appearance.

3. Furniture and Interior Design
   Designers select pre-painted steel for modular furniture, partitions, and ceilings. The smooth surface and wide color range support creative interiors.

4. Large-Span Buildings and Warehouses
   Construction companies rely on PPGL coils for warehouses and factories that must withstand decades of service with minimal maintenance.

5. Appliances and Electronics
   Appliance makers use these coils for refrigerator doors, washing machine panels, and microwave housings. The coatings resist humidity and keep products looking clean.

6. Cold Storage and Food Industry
   Cold room manufacturers prefer PPGL for its resistance to condensation and hygiene benefits. Food storage facilities benefit from its long lifespan.

7. Temporary Housing and Prefabricated Structures
   Engineers design prefabricated homes and site offices with lightweight pre-painted sheets. The materials provide strength, speed of installation, and visual appeal.

Advantages of Using PPGI and PPGL

• Wide range of colors that reduce the need for on-site painting.

• Strong durability against scratches, corrosion, and weather extremes.

• Easy fabrication: companies cut, bend, and shape the coils without damaging the surface.

• Long-term cost savings through reduced repairs and replacements.

• Fully recyclable and eco-friendly materials.

Why Choose Basekim as Your Supplier?

Basekim supplies PPGI and PPGL coils that meet global standards. The company tailors sizes, thicknesses, and colors according to project requirements. Clients benefit from consistent coating quality and timely deliveries. In addition, Basekim’s experience in international trade ensures smooth logistics and technical support for industries worldwide.