Materials

For high-quality architectural products, we would recommend extruded material specified from 6063/6060 aluminium extrusions. For fabricated products, such as rain screen panels, we would recommend AQ-certified products such as Novellis J57sUP or Aluminium Duffel 55HX. For expanded mesh, widely used for car park cladding, we would recommend sample approval. Other grades of aluminium can be anodised to give good results, please contact us for advice.

Jigging

The first step is to make a secure electrical connection onto the article to be anodised, this is normally carried out using a plastic clamp onto a 20mm bar of aluminium. Other methods can be used if the ensuing mark is on a visible surface and therefore unacceptable - for advice on jigging and design please contact us through our technical enquiries form.

Etching

This part of the process gives the material its visual appearance and determines the gloss and reflectance of the anodic coating. Control of temperature and time, in addition to chemical composition is crucial to control the rate of reaction of the bath. Continuous monitoring of this process guarantees contract conformity. Varying levels of gloss can be specified.

Anodising

Key parameters in the production of the anodic film include the temperature, bath composition and voltage applied along with the complex rectifier programme cycles are crucial in determining the consistency and accuracy of micron films; as the film thickness grows, electrical resistance increases and cooling capacity of the tanks becomes a critical parameter, for 25-micron film ineffective cooling can result in accelerated film propagation, excess porosity and a soft film, our installed chillers are specified to ensure we can produce 25-35 micron films across all five anodising tanks simultaneously.

Consistency

United Anodisers is unique in Europe in its ability to produce hard consistent films, exceeding the requirements of Qualanod, BS3987 and Z33 to ensure process control is maintained each and every load is checked day and night. Recent major capital expenditure has further distanced the company from its major competitors with additional low energy chillers installed and a significant solar panel array to power them.

The Colouring Stage

United Anodisers' investment in technology at the colouring stage goes far beyond its major European competitors. We are still the only anodiser in Europe to offer Unicol colouring accuracy and now monitor colour using state-of-the-art colour measurement equipment. We have seven high-performance spectrophotometers onsite and a set of 3 gloss meters.

This gives optimum colour control without an equivalent in the industry and ensures consistency of the overall building appearance.

The Sealing Process

Each load is checked for seal quality day and night using one of our three anotest instruments. This is a well proven HOT SEALING process, and it sets us apart from other anodisers.

Testing

The level of testing imposed at United Anodisers is considerably more extensive than that of its competitors. For example, to test film hardness, we are the only anodiser within Europe to the best of our knowledge with regular SUGA abrasion testing. This was, historically and at our instigation, built into the old British Standard as a major step towards improving anodic film performance.

Current handheld abrasion testing is in more general use elsewhere but typically on a day-by-day sample frequency rather than each process load. We firmly believe that effective testing prevents out-of-spec products from arriving at customers sites, and we will continue this test regime as we further develop our process and testing capabilities.