Durable 2D Barcode for anodised surfaces

AHC Oberflächentechnik now uses a new, automated method for documenting the anodisation of safety-critical aluminium components.

A comprehensive quality management system ensures that each individual component can be traced from its manufacture, throughout its service life until its disposal - an essential precondition for safety-critical applications, whether in the aerospace or in the automotive industry. The surface treatment of corresponding components is also documented, for example the type and duration of the coating process, temperature stress, chemical exposure or the position of the component on the coating rack. At present, this documentation is still carried out by manual procedures such as photography of the components on the rack or the entry of relevant data into a PC via keyboard.

In the field of anodisation and hard anodisation of aluminium components AHC Oberflächentechnik, in collaboration with a barcode manufacturer, has now developed a method for the automatic recording and life-long tracing of treatment data for safety-critical components. It uses 2D barcodes, stuck on to each component to be coated. Needless to say, the areas selected for this purpose are parts of the surface irrelevant to the later function of the component. The barcodes nevertheless go through the complete surface treatment applied to the components. And this is where the know-how comes in: the knowledge of the suitable material for the barcodes and their composition.

Many different stresses are undergone during a coating process. According to the delivery condition of the components, pre-treatment is necessary. Fouling by oils, greases and polish residues can mostly be removed by organic solvent-based cleaners which have little abrasive effect on metals. Rolled, drawn, pressed and heat-treated skins and any oxide coatings already formed are removed by pickling in alkaline or acidic solutions. During the actual hard anodisation or technical anodisation, the so-called main treatment, the components come into contact with dilute sulphuric acid plus oxalic acid at temperatures near 0°C (hard anodising) or 16 – 21 °C (anodising). If the coatings are then sealed or coloured, the barcodes are also subject to further stresses. For sealing, the products are immersed in deionized hot water at approx. 96 °C or in special sealing solutions. For colouring, colour baths are used and the components may be coloured electrolytically.

The barcodes resist all the chemical and thermal stresses which they and the components undergo during surface treatment. Barcode marking by using these newly developed durable barcodes creates the preconditions for product tracing and end-to-end quality monitoring. AHC Oberflächentechnik will be pleased to answer any questions customers might have regarding the practical implementation or cost-benefit aspects.

Press contact:
Jürgen Diesing
juergen.diesing@ahc-surface.com


Caption:
2D Barcode on an aluminium component hard anodised and coloured black by using the HART-COAT® process