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PPGI/PPGL FAQs

PPGI and PPGL have been very popular in the market in recent years due to their corrosion resistance and decorative properties. More and more people want to purchase PPGI and PPGL, but many people have many questions about these two products.

PPGI and PPGL have been very popular in the market in recent years due to their corrosion resistance and decorative properties. More and more people want to purchase PPGI and PPGL, but many people have many questions about these two products.

ppgl
  • PPGI’s full form is Pre-Painted Galvanized,The coating is Zinc Coating.
  • PPGL’s full form is Pre-Painted Galvalume,The coating is Aluminum Zinc Alloy Coating.

HS codes vary depending on the coating type, product specifications, ingredients, uses, etc. You can determine the specific HS code from the manufacturer, and the HS codes for PPGI and PPGL are under category 7210. For example:

  • HS code 72107010 for painted steel with a thickness of less than 1.5mm.
  • HS code 72104910 represents galvanized steel with a tensile strength of not less than 440MPa.

Common paint coatings for PPGI and PPGL include polyester (PE), high-durability polyester (HDP), silicon-modified polyester (SMP), polyvinylidene fluoride (PVDF), etc. Different paint coatings have different hardness, bending performance, corrosion resistance, weather resistance, etc. The following table shares the comparison of these four paint coatings:

Paint typeHardnessBendingCorrosion resistanceWeather resistancePriceFilm thickness (μm)
PEExcellentGoodGoodGoodLow20
HDPGoodExcellentGreatExcellentMedium20
SMPGoodGoodGreatExcellentMedium20
PVDFGoodExcellentExcellentExcellentHigh25

Wanzhi Steel can produce the above steel grades and thicknesses. Please contact us for details.

There are many colors for PPGI and PPGL, and Wanzhi Steel can provide all colors in all RAL color cards.

Common colors for PPGI and PPGL:

  • Neutral colors: white, gray, black, beige, etc.
  • Earth tones: brown, green, tan, etc.
  • Bright tones: red, blue, yellow, etc.

Both PPGI and PPGL are suitable for use on roofs. You only need to consider the application environment and cost budget.

PPGI is cheaper than PPGL, but PPGL has higher corrosion resistance than PPGI. PPGL is more suitable for harsh outdoor environments, such as coastal areas.

The following table recommends the coating weight of PPGI and PPGL in different corrosion environments:

Substrate typeNominal coating weight (g/㎡)
Corrosive environment
LowMediumHigh
Zinc coating (Z)90/90125/125140/140
Aluminum-zinc coating(AZ)50/5060/6075/75

Note: PPGI uses Zinc coating, and PPGL uses Aluminum-zinc coating (AZ)

The difference between PPGI and PPGL can be analyzed from the aspects of substrate, substrate composition, weight, appearance, corrosion resistance, weather resistance, service life, application and price.

DifferencePPGIPPGL
Substrate materialGalvanized steel (GI)Galvalume (GL)
Substrate compositionMainly zincAluminum-zinc alloy (usually 55% aluminum, 43.3% zinc, 1.5% silicon)
WeightCoating thickness is the same, Zinc coating weight is heavierBecause aluminum has a lower specific gravity than zinc, aluminum-zinc coating is lighter
AppearanceSurface is smooth and shinyBecause of aluminum, aluminum adhesion is good, the surface is smoother and the gloss is better
Corrosion resistanceGood corrosion resistanceBecause of the combination of aluminum and zinc, the corrosion resistance is better than PPGI
Weather resistanceGoodBetter weather resistance than PPGI, can withstand temperatures up to 315℃, and can better resist wind and rain erosion
DurabilityGoodMore durable than PPGI
ApplicationBuilding wall panels, roofs, warehouses, shopping malls, cars, home appliances, etc.Scenarios that require higher corrosion resistance
PriceRelatively lowRelatively high, because of its better performance
Service life20-30 yearsPPGL has a service life of 2-3 times that of PPGI.

From the table above, we can see that the overall performance of ppgl is better than that of ppgi, and the price of ppgi is relatively low.

After comparing the two, each has its own advantages and disadvantages. When choosing, you should consider where you will use it? What is the cost budget of the project?

It should be noted that PPGL does not have as many colors as PPGI, and PPGL has certain limitations in using colors.

PPGI and PPGL are not fireproof in themselves. Both have certain heat resistance. PPGL has better heat resistance and can withstand temperatures up to 315℃.

Before calculating the weight of PPGI and PPGL plates, we must first understand their density. The density of PPGI and PPGL plates is 7.85g/cm³. Secondly, we must understand the weight calculation formula. The calculation formulas for both are the same.

Calculation formula: Weight (KG) = length (m) * width (m) * thickness (mm) * density

For example: a PPGI steel sheet with a length of 1500mm, a width of 900mm, and a thickness of 0.5mm.

Weight = 1.5*0.9*0.5*7.85=5.29875kg

In the standard system for galvanized steel sheets and related materials, GSM (Grams per Square Meter) is usually used to describe the weight of the zinc coating, that is, the weight of the zinc layer per square meter of steel sheet, which is an important indicator for measuring the corrosion resistance of galvanized steel sheets.

In order to ensure the adhesion and corrosion resistance of the coating, GI and GL substrates need to undergo a series of treatments before painting.

  • Degreasing: To remove oil, grease and other impurities on the surface of the steel.
  • Water washing: Used to remove residues on the surface of the steel, such as degreasing agents, pickling solutions, etc.
  • Phosphating: A relatively important step. In order to enhance the corrosion resistance of the coating, the steel plate is immersed in a solution containing phosphates. A stable phosphate film is formed on the surface of the steel through chemical reactions, which can improve the adhesion of the coating.
  • Passivation: The passivation treatment is to further improve the corrosion resistance of the phosphate film.
  • Drying: Dry the steel plate to remove moisture from the surface.
  • Inspection: Perform a comprehensive inspection of the steel plate to ensure that there are no defects such as oil, rust, scratches, etc. on the surface.
  • Production: 3 pre-painting production lines to ensure product delivery; more than 200 rollers to produce various patterns.
  • Inspection: Complete testing process to ensure product quality, including thickness test, coating/paint thickness test, gloss test, salt spray speed test, impact test, weather resistance test, etc.
  • Packaging: Wanzhi Steel ensures that all packaging is very strict and meets the required standards to avoid damage during transportation and storage.
  • Experience and Service: We have 13 years of experience in steel export, and our products have been exported to more than 120 countries. We have successfully completed more than 1,200 foreign projects and received praise from customers from different countries.