Which is Better PPGI or PPGL?

Pre-painted galvanised iron steel (also known as PPGI) and pre-painted aluminium galvanised steel (PPGL) are two different types of colour coated steel. both PPGI and PPGL are used in a wide range of industries such as construction, transport and the appliance industry. They are both very similar, but still have unique differences.

 

Different types of substrates

Galvanised steel PPGI is completely coated with zinc, while galvanised steel PPGL is coated with aluminium, zinc and a small amount of silicone. This provides superior corrosion resistance and durability compared to typical galvanised coatings. This is the biggest difference between PPGI steel and PPGL and is responsible for many of the differences in weight, product life, appearance, price, application and other characteristics.

 

Weight difference between PPGI and PPGL

As the specific gravity of aluminium is less than that of zinc, the aluminium-zinc coating on PPGL will be lighter for the same coating thickness. This also means that the same weight of Al-Zn coating can cover up to 3% more space than PPGI.

PPGI Coil

Service life

Both zinc and Al-Zn coatings help to protect the metal from rusting, thus extending the life of the product. With PPGI, the base metal can be damaged when the zinc coating corrodes. Galvanised PPGI sheets will last approximately 10 to 15 years.

 

With the aluminium-zinc alloy on PPGL, the aluminium-rich material corrodes slowly, while the zinc-rich part corrodes preferentially. This provides additional corrosion resistance to the rigorous PPGI zinc coating. ppgl lasts three times longer than ppgi.

 

Differences in appearance

PPGL surfaces look smoother than PPGI surfaces. As aluminium has better adhesion than zinc, PPGL may not require the same paint pre-treatment as galvanised sheet.

 

Heat and Erosion Resistance

PPGL offers better heat resistance than PPGI and can withstand temperatures of up to 315°C. As PPGL offers increased corrosion resistance through a dense aluminium layer, it further protects the base metal from erosion. However, the cut edges of PPGL are less protected due to the honeycomb structure of the coating which does not adequately protect the exposed edges. A coating can be applied to these exposed edges for additional protection.

PPGI Coil

Applications for PPGI and PPGL

Both PPGI and PPGL are used in a variety of roofing and wall panel applications. PPGL is better suited to harsh outdoor environments such as coastal areas exposed to seawater due to its better corrosion resistance. ppgl also has excellent heat resistance making it a popular material for ovens and chimney pipes.

 

Price differences

PPGL is usually slightly more expensive than PPGI due to higher performance and fewer manufacturers. Working with an experienced supplier of industrial adhesives and coil coatings will help you understand the various coating options available for pre-painted metals.

 

Best Steel is a PPGI Coil manufacturer that provides high performance functional coatings for steel sheets manufactured using a continuous coil coating process. We offer industry-leading high-tech engineers who provide troubleshooting and custom chemical solutions to meet your adhesive or coating needs.

 

Please contact us with any questions regarding the best type of adhesives and coatings for your pre-coated coil-coated metal process.