Here at Karas Plating we have been providing impeccable anodising processes for customers the length and breadth of the UK for more than seventy years. In that time, we have earned ourselves a reputation for excellence, thanks to the dedication and professionalism of our workforce. A versatile and effective form of metal finishing, anodising has numerous applications across a range of industry sectors.
Anodising is an electrolytic passivation process used exclusively with aluminium or titanium. Utilising the piece metal to be treated as the anode in an electrical circuit, this method applies a film to the aluminium that alters its visual appearance to something more pleasing. Durable and long-lasting, this film is usually dyed with a colour or just sealed.
The anodising process involves passing an electrical current between the anode – that is, the target metal – to the cathode. This current results in oxygen being released at the anode end of the circuit. The oxygen, combined with the base aluminium, forms aluminium oxide as a film around the metal. The thickness of this anodic film can be set by the amount of time the metal spends in the anodising tank.
Changes to the concentration and temperature of the electrolyte, as well as the current density help us improve the quality of the anodic film. The film itself has a honeycomb structure that is naturally porous and requires sealing to give it the weather resistant properties desired of it. At Karas Plating, we always use sulphuric acid for our anodising.
The anodising process increases the resistance of the metal to wear and corrosion. It also provides a more adhesive surface for glues and paint primers than would be the case with bare metal. This helps to strengthen the aluminium base and improves the metals performance as a building material.
The anodic film can also serve a number of cosmetic purposes, as a thicker, more porous film can incorporate various dyes in its make-up. Likewise, a thinner, transparent coating can create interesting interference effects with reflected light. Here at Karas Plating we can anodise your aluminium parts in a number of colours, including red, green, gold, blue, black and natural.
Anodising can also be used in the production of dielectric films for electrolytic capacitors, as well as preventing the galling of threaded components like screws and bolts.
Anodised aluminium has many benefits compared to the raw material. It provides improved resistance to abrasion and corrosion and offer proven long-term durability. The process creates a uniform finish to the metal, as the anodic film is actually grown onto the surface of the aluminium.
This means that it cannot simply be peeled off and provides an excellent surface for applying glues and paint primers, offering improved adhesion. When properly sealed, the anodic film is impermeable to water and other moisture. From an environmental point of view, the process is ideal, as the materials are completely recyclable and does not produce any solvent or CO2 emissions.