A Guide to Polyester Powder Coating and RAL Colours

When it comes to Sieger’s high quality aluminium glazing systems, the glass is the main element. But choosing the right frame finish and colour can also have a significant impact on the look of the glazing and the overall building design.

Some clients want the frame the match the building finishes, so choose a colour that blends in seamlessly with both the internal and external walls for the most minimal aesthetic.

On the other hand, choosing a frame that contrasts with its surroundings can create a bold and contemporary design that highlights the high quality glazing system and creates a striking design feature.

Ultimately there is no right or wrong choice when it comes to frame colour, it comes down to personal preference and what the client wants to achieve in terms of aesthetic.

At Sieger we have a wide variety of frame finishing options including polyester powder coating and anodizing. Our polyester powder coating comes in the full range of RAL colours so our glazing systems can be manufactured to meet any specific design requirements.

green window frames and grey framed windows and doors for a contemporary glazing style on a new build home

Polyester Powder Coating (PPC)

This is the most common type of frame finish for aluminium, it is a positively electrically charged dried powder that is sprayed onto the frame using an electrostatic gun.

The frames are then placed in an oven and heated to start a chemical reaction that enables the powder coating to form a durable outer layer that cools to a hard finish.

One huge advantage of using polyester powder coating is that it doesn’t release harmful solvents or pollutants into the air. This makes PPC an extremely environmentally friendly finishing option, particularly when compared to some cheaper frame finishes.

Standard thicknesses vary between glaziers, most PPC layers are 40-60 microns thick. For a PPC to be considered ‘marine grade’ (thick enough to protect the frame from harsh sea air), it must be 60-80 microns thick.

The PPC used by Sieger is marine grade as standard, as we want to ensure our high-quality systems have a long lifespan in any environment. 

When specifying marine grade framing for your glazing systems we recommend pre-anodising the frame and then applying a PPC finish. This added layer of protection combined with the natural rust and corrosion resistant properties of aluminium creates an extremely durable frame.

Most of Sieger’s glazing systems have a set of standard RAL colours to choose from, but any colour can be chosen, there just may be additional costs incurred.

large RAL colour chart on show at the sieger glazing showroom in Amersham
double height modern home extension with a pastel kitchen and contrasting black bifold door frames

RAL Colours

The RAL colour chart is a European colour matching system that is used to define colours for paint, coatings and plastics. This is the colour range used for polyester powder coatings.

Colours are sectioned into 9 groups based on their hues. Each colour has a four digit number assigned to it and colours in the same group will start with the same two numbers.

The number ranges for each group are as followed:

Yellow hues RAL 1000 – RAL 1037

Orange hues RAL 2000 – 2013

Red hues RAL 3000 – 3033

Violet hues RAL 4000 – 4012

Blue hues RAL 5000 – 5026

Green hues RAL 6000 – 6038

Grey hues RAL 7000 – 7048

Brown hues RAL 8000 – 8029

White & black hues RAL 9000 – 9023

Our Chaucer Road project featured a Sieger 120 Bifold Door with dark bold frames that contrast beautifully with the pastel interior colour scheme of the modern kitchen extension. The aluminium framing was finished with a polyester powder coating in RAL 9005, also known as jet black.

Woodwind, one of our new build home projects, benefitted from a full glazing package from Sieger, and all aluminium frames were finished in the same RAL colour to create a cohesive design.

The client chose RAL 7033, also known as cement grey, which is a grey hue colour with unique green undertones. The frames don’t blend or contrast with the home, but instead complement the building finishes.

At the Sieger showroom in Amersham we have a large RAL colour chart on show and a wide range of glazing system on display with different frame finishes.

It is important to discuss with your glazier which design aesthetic you want to achieve and visiting the showroom will help to ensure that you choose the right glazing system for your project.

Our technical team are on hand to answer any questions and help you choose the right frame finish for your glazing.

To speak to someone or to book a showroom visit call 01494 722 882 or email [email protected]

two pane polyester powder coated white slim sliding door from sieger

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