Surface Treatment

There is a vast array of Surface Treatments which are carried out to a wide variety of materials for decorative or engineering purposes. The Surface Treatment might involve plating on top of a substrate material or altering the surface of the substrate material, typically to confer some corrosion resistance advantage. An example of where a process offers both corrosion resistance and decorative enhancement is anodising.

Further examples of Surface Treatments which alter the nature of the substrate material include:-

	Chromating.
	Phosphating.
	Galvanising.

Many different metals are plated on a variety of substrates, for both decorative and engineering purposes. Examples of metals plated include zinc, copper, chromium, cadmium, silver gold and rhodium. Sometimes a number of plating processes are employed to give the desired end finish, for example, electroless nickel plating prior decorative plating of chromium on plastic items.

To ensure a satisfactory finish a number of pre-treatment processes are often employed, for example cleaning and acid pickling. The surface treatment finish might also require a further stage such as passivation post chromium plating or hot demineralised water seal post anodising of aluminium.

With such a variety of processes available and often undertaken on a single site, the waste streams produced are themselves often varied. Some plating solutions such as Cd and Zn may contain cyanides which require removal, along with the metal, prior to discharge to drain. Cyanide destruction can be achieved through chemical oxidation at high pH by the addition of sodium hypochlorite.

For more information, see our products range or contact the sales team by emailing sales@reverseosmosis.co.uk