There has been much talk about pretreatment of Aluminium prior to powder coating in the last few years with the imminent ban this year on using chromium compounds in the pretreatment process. QUALICOAT has for many years promoted the use of chrome-free pretreatments and the majority of coaters in Europe already utilise such systems. Here in the UK just over half of QUALICOAT licenced plants are chrome-free with other members being ready for an imminent switch over.
All this activity has led to discussion of alternative forms of pretreatment, one such system is to pre-anodise the aluminium prior to powder coating, this is sometimes referred to as ‘flash-anodising’. This has been used for a number of years on the continent for the ‘Seaside Class’ of powder coating under the QUALICOAT Standard, but the benefits of pre-anodising could be extended to regular projects where a more robust finish is required, specifically where cut edges are going to be exposed.
QUALICOAT has now set up a working group to discuss how this can be achieved in practice with a view to bringing this form of pretreatment to mainstream coatings. In general terms, the benefits of pre-anodising is the virtual elimination of filiform corrosion from cut edges, the downside is that powder coating has to be completed in a very short time after pre-anodising, making it necessary to pre-anodise in the same premises where the coating takes place. Two members of QUALICOAT UK & Ireland have already invested heavily in the installation of anodising plants to take advantage of this method of pretreatment. With the increasing take-up of the more resilient Class 2 and Class 3 powders, the adoption of pre-anodising prior to powder coating seems a logical progression.
Quality and consistency of quality, continues to be highlighted by QUALICOAT UK & Ireland, which includes third party testing of all certified powder formulations and pretreatment systems that make up the QUALICOAT approval process. For specification support, any member of the association can offer advice and guidance, for updated information about the use and specification of QUALICOAT in the UK and Ireland, please visit the associations’ website at www.qualicoatuki.org