Our Service The Colouring of Aluminium Reflectors The majority of aluminium reflectors manufactured by ACL-Lichttechnik GmbH is offered uncoloured, that means silver coloured. But it is easily possible to colour the reflector surface. This is done after the anodising (please see April issue of our newsletter) and even before the sealing of the oxide layer. The electro-chemically created colourless and transparent oxide layer will either be coloured with colouring pigments (dye colouring or adsorption dyeing) or electrolytically coloured. A further colouration process is the “Integral Colouring” which combines anodising and colouring to simultaneously form and colour the oxide layer.

The dye colouring, mainly used by ACL-Lichttechnik GmbH, is a two-step process and is carried out by means of dipping (dip colouring) the reflector in a colouring solution after the anodising. The colouring pigments are either organic (metal complex dyes, e.g. golden yellow) or inorganic (e.g. blue, red, gold, black). During the colouring process the dyes are partly adsorpted, partly chemically fixed in the upper part of the oxide layer. The degree of colouring of the oxide layer is determined by the anodising conditions, the thickness of the oxide layer, the volume of the pores as well as the type of dye used and the colouring conditions (dye concentration, pH and temperature).

Gold-coloured reflectors are mainly used in luminaires for baker’s shops. Reflectors coloured with red and pink are used in butcher’s shops. Black-coloured reflector surfaces are for glare reduction.

After colouration the reflector surface needs to be perfectly sealed (see our April newsletter for more detailed information on the sealing process).

For further questions about the colouring of our aluminium reflectors please click here.