Decorative anodizing is anodizing to produce a decorative finish with a uniform or aesthetically pleasing appearance as the primary characteristic. Such applications include bright trim, lipstick holders, shower screens and lighting reflectors.
Aluminium is highly reflective of light – second only to silver. It does not tarnish although can develop marks from staining or manual handling. Anodizing protects against these. The reflectance is reduced slightly for alloys and by anodizing.
Various surface textures can be produced on aluminium including matt, brushed, bright and mirror-like finishes. Also, anodizing enables colorants such as dyestuffs to be absorbed into the coating to produce stable colorations.
The important product quality criteria are:
- visible defects, surface texture and, if appropriate, colour
- coating thickness
- sealing quality
The requirements for appearance are more demanding than those for architectural anodizing while those for sealing quality are less onerous. Light reflection properties can also be important depending on application.
The inspection of QUALANOD-licensed anodizing plants includes the testing of samples of anodized products to verify that the correct quality is being achieved.