Sheet metal is an incredibly versatile material, being used for a seemingly endless array of purposes. It is easily made into many shapes and parts and has good mechanical strength. However, most sheet metals, especially steels, are very prone to corrosion. Shelving units are commonly made from sheet metals so they must be protected from corrosion. Corrosion occurs when metal atoms are in contact with oxygen and a chemical exchange of electrons is allowed to occur (the oxygen is reduced and the metal is oxidised). There are many ways in which sheet metal manufacturing companies such as Premier Engineering can include protection against corrosion in their shelving units:
This is the simplest solution to corrosion resistance in sheet metal manufacturing, placing a physical barrier between oxygen and metal to prevent any reaction from occurring. It does have some major flaws, if any of the surfaces is removed or scratched, corrosion will occur rapidly. This requires frequent upkeep.
Galvanising involves applying a coating of one metal onto another. This is frequently performed on steel shelving units by coating with zinc. The zinc forms a protective layer when it corrodes which does not allow any deeper corrosion on the steel. This is much more durable than paint as damage to the layer will regenerate by new zinc corroding to fill the gap.
Powder coating is commonly used in sheet metal manufacturing to form a protective film over the surface, preventing the chemical interactions in corrosion. This is a good, long term solution to protective coatings on shelving units.
Anodising is an electrical process used to strengthen the natural layer of oxides on a metal surface; this makes them much less likely to corrode later. The technique is referred to as electrolytic passivation in sheet metal manufacturing, where the metal is placed in a chemical bath and impressed with a current.