SURFACE TREATMENT

COLORAL divides its surface treatment in two main categories :

Electrochemical techniques

Anodic Oxidations

 

Anodic oxidation of aluminium is an electrochemical process that consists in building a porous and colorable oxide layer on the surface of the part.

This layer has unique properties :

  • Corrosion proof, colorable (preserving its metalic character), enhance mechanical and tribological properties.

Coloral proposes two different anodic oxidations :

  • Sulfuric decorative anodisation.
  • GL anodisation.

Coloral also provides anodisation of titanium. The oxide layer is limited and can be intrinsically colorated through incident light refraction. This is why the colour range is limited and the intensity depends of the initial metal surface.

Chemical conversion (Alodine)

 

COLORAL proposes two kinds of conversions. Alodine 160/161 which gives a yellow shade to the parts and alodine 400 with neutral color. These treatments protect aluminium from corrosion while the electrical conductivity remains and are compatible with ROHS norms. These treatments are also used as under layer before painting.

Decorative techniques

Laser engraving

 

Logos and texts can be marked on almost every material. The laser beam removes part of the material, visualisation being made by contrast.

This technique is often used on anodised and colored aluminium, by removing the colored layer, the contrast of the engraving with aluminium shade on a colored background is excellent.

This process using computer files (for example DXF, Illustrator…), can help COLORAL customers to give easy directions for what they want to engrave. This way, personalisation and serial number printing can be done at low cost.

Silkscreen printing

 

Process allowing to print logos or texts by ink or varnish deposit by selectively opened screens by exposition to light.

  • Printing into the oxide layer, the printing is not palpable.
  1. Aluprint  : Deposit of various inks shades into the oxide layer.
  2. Selective screen : Selective introduction of colorant into the oxide layer.

Printing on the oxide layer. Deposit of varnish on the oxide layer, the printing is palpable. Silkscreen printing allows larger printings and also printings on cylindrical parts.

Buff printing

 

Process allowing to print logos or texts by transfer from a plate to the part via a stamp.

  • Printing into the oxide layer, the printing is not palpable.
  1. Aluprint  : Deposit of various inks shades into the oxide layer.
  2. Selective screen  : Selective introduction of colorant into the oxide layer
  • Printing on the oxide layer. Deposit of varnish on the oxide layer, the printing is palpable.

Sandblasting

The principle is based on the use of a live force to hit the surface of the part ; the thrown up particle leaves a trace. The addition of thousands of traces left on the part gives a regularly mat final aspect.

photo stefano iori