Vacuum metalising is the process of evaporating a film of metal onto products under vacuum.

The main advantages of vacuum metalising are finish, flexibility and price. Vacuum metalising allows for highly reflective, bright mirror finishes to be achieved, giving products a deep brilliant lustre. These affects can not be replicated by merely painting the parts. In fact the finish produced is almost identical to electroplating.

However vacuum metalising has a number of advantages over electroplating. Unlike electroplating, that requires a specific plating grade of ABS to be used, vacuum metalising is far more versatile, successfully coating most types of plastic. Also, unlike electroplating it is possible to mask off mouldings, so that only specific areas are metalised. Again, unlike electroplating different colours and finishes can be achieved. Further to this vacuum metalising is also a cost effective alternative to traditional plating processes, offering a comparable quality of finish, yet providing considerable cost savings.

The vacuum metalising process can be broken down into specific sections, each of which is described below;

Parts loaded onto jigs

To begin the metalising process, parts are loaded onto holding jigs. These jigs are specifically designed for the products loaded onto them, thus ensuring the best metalising coverage possible is achieved.

Base Lacquer

Before the parts can be metalised, an adhesive base lacquer is sprayed onto the parts. There are many different types of lacquers that can be applied. We select the most suitable lacquer for the product and its end use. Base lacquering maximises the metalising process and ensures that the desired effect is achieved.

Once sprayed, a flash off period is given to the parts. Parts are allowed to air dry in a controlled air conditioned clean room. This helps to ensure an even finish, free of drips, sags and runs is achieved. Once the parts have been flashed off, the parts are transferred into ovens for the base lacquer to cure. Again the temperature and duration in the oven is specific to the base lacquer applied to the parts.

Metalising

Once the parts have been cured, they are taken from the oven and loaded onto vacuum chamber trolleys. These trolleys are loaded into the vacuum chamber and the metalising stage can begin. The chamber is pumped down to a pre determined pressure specific to the parts being processed. When this has been achieved, 99.9% pure aluminium is evaporated in the chamber and the resulting vapour coats the products with a uniform film of metal.

Top Coat

As described above the metalising process coats the parts with a very high grade of aluminium. It is this, that once applied is highly reflective, and a clear protective top coat is then added to preserve the affect. For some parts however, a chrome finish is not the desired effect. The coating of aluminium is then used as a base from which an array of different coloured lacquers can be applied, as well as satin and antique finishes. Again the parts are given specific time in the oven to cure.

Unjigging and packing

When the parts have been cured, they are then removed from the jigs and inspected against customer agreed criteria. Post inspection parts are placed in approved packaging ready for despatch.