Electrophoretic sealing (Topic: 14126)

This is a process where the sealing of the anodic oxide layer is said to be obtained by electrophoresis. The deposition of an acrylic resin onto an unsealed anodic coating by electrophoresis has become the standard method of sealing for many extruded architectural products in Japan. The most well-known electrophoretic sealing process is called "Honnylite". The profiles are pre-treated and anodised conventionally to a thickness of about 8 µm, and then most of the profiles are electrolytically coloured. After this operation the profiles are electrophoretically coated with 8ñ10 µm of clear acrylic resin, and stowed at about 160ƒC. The surface finish has usual a high gloss or a semi-matt appearance.

The resin is claimed to penetrate the pores of the oxide film as well as giving a surface layer.

However, investigations indicate that the particle size of the acrylic resin has such a diameter that the resin will not enter the pores in a sulphuric acid anodised film, and will just coat the surface.