VOICE OF THE INDUSTRY
Jigging points in suitable positions for optimal coating
Terracotta powder coating – with a 25-year guarantee for adhesion, colour and gloss level
REVISION OF POWDER COATING STANDARD BS EN 12206-1 Richard Besant talks us through the important revisions to the European standard for powder coating and outlines further measures to ensure the highest possible performance of your powder-coated finish. POWDERTECH
RICHARD BESANT IS DIRECTOR OF POWDERTECH (CORBY), A SPECIALIST ARCHITECTURAL POWDER COATER. POWDERTECH IS A MEMBER OF CAB (COUNCIL FOR ALUMINIUM IN BUILDING) AND ALFED (ALUMINIUM FEDERATION), AND RICHARD IS A MEMBER OF THE COMMITTEE FOR EN 13438 – THE EUROPEAN STANDARD FOR POWDER COATING ON GALVANISED STEEL.
FC&A – NOVEMBER – 2020
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or specifiers and powder coaters of architectural aluminium, the recognised European Standard is BS EN 12206. Standards do not stand still and are revised in line with developments in technology and ongoing research. December 2020 will see the publication of the latest edition (BS EN 12206-1) after a long period of consultation. The benefit of the EU standards is that they have independent input from all interested parties, and the result is a practical standard that draws its information from a cross-section of the industry. For those with a long memory, the original version of this standard was BS 6496 first published in 1984 and withdrawn in 2017 which meant that BS 6496 and BS EN 12206, which drew heavily from the text and tests of BS 6496, ran in parallel for 13 years, giving plenty of time for a transfer from one standard to another and ending any specification confusion. Standards are not the most inviting of documents to plough through, so I thought it might be helpful if I took this opportunity to point out the significant changes in the latest standard, BS EN 12206-1:2020. 22
Equivalence in pre-treatment systems This is the most significant stage in powder coating, and BS EN 12206-1 recognises the equivalence of the three more common processes broadly categorised as chromebased, chrome-free and pre-anodised. Because BS EN 12206-1 is a performance-based standard and is not prescriptive as to the best pre-treatment process, it uses a range of performance requirements that must be met in order to meet the standard. It is worth noting that the use of chrome-based systems is likely to be phased out in the near future because of the proven carcinogenic and mutagenic effects associated with chrome.
Thickness of coating Specifiers frequently ask “What is the correct film thickness” and “Is thicker better?”. BS EN 12206-1 addresses this in two ways. The minimum film thickness has been set as an absolute number, 40 microns. In addition, there is a recognition that different powders and different locations may need individual or local arrangements to achieve the performance requirement as set out in the standard. To answer the initial question, no, thicker is not always better.
Flexibility testing Since the standard was first written, powder coating systems have improved significantly, resulting in the now common specification of Class 2 or super-durable products. These products have enhanced ultraviolet (UV) light performance for colour and gloss retention over an extended period of time though it should be noted that the specification of a Class 2 or super-durable product does not increase the corrosion resistance of the product.
