Chrome, gold, brass or copper effect plating on plastics
Vacuum Metallising is also known as High Vacuum Metallising, Vapour Deposition, Aluminium Evaporation and PVD (Plasma Vapour Deposition). This process is the first step towards achieving the chrome effect on plastic products. A thin layer of aluminium of about ½ micron thick is plated onto many plastic substrates such as Polystyrene, ABS, Polycarbonate, Polypropylene, SAN, PA6, PA66 and most if not all engineering plastics to give a chrome effect.
Acetal plastics should be avoided, due to the difficulty in obtaining good adhesion, although this can be improved if coating within a plasma system, which Dual offer, with polyethylene being likewise.
Although Vacuum Metallising looks similar to chrome electro plating it is not as robust and is advised to be used for decorative items only. These items are usually bezels, trophies, lighting, vacuum flasks, and point of sale, coffin furniture plus a myriad of other items. The cost of Vacuum Metallising is also a great advantage with savings of up to 50% in comparison to real chrome.
As noted in the Lighting Reflectors Link to Lighting Reflectors section, Vacuum Metallising is far more reflective than traditional chrome. It’s almost as good as silver, which is why it is the first choice for all reflective requirements on plastic, steel and aluminium.
Tinted Top Lacquer and Dip Dyeing Process
Chrome, brass, copper and gold effects on plastics are achieved by using Tinted Top Lacquer or the Dip Dyeing Process. Tinted Top Lacquer and Dip Dyeing Process require the components to be metallised. Once metallised the tinted top lacquer is applied straight onto the metallised surface and then the dip dyed to give the chrome effect.
The tinting effect is achieved by adding special dye colours with a mix of red, orange and yellow concentrated dyes into compatible top lacquers; these are mixed to achieve the desired colour and sprayed by either automated or hand application.
The alternative to tinted top lacquers is Dip Dyeing Process whereby a tank of special dip dye is made to the specified metallic colour and the substrates are submerged into the dye for a determined amount of time and washed off in de-ionised water. The metallised parts have a top lacquer applied before they are dip dyed, the lacquer acts as an absorbent for the dye as a result the items, post washing, show an evenly spread metallic colour.
The advantage of tinted lacquer is, there is no extra processing, whereby dip dyeing calls for two extra processes including a drying operation as well as the dipping itself. With dip dyeing more even colours are achieved.
Chrome effect on plastics and prototype resins are extremely popular with new models of cars and commercials especially when these models are being built as one offs for stylist or designer approval. Often the case is that ABS plastics are unavailable due to rapid prototypes being made of other resins which cannot be electro plated with chrome, this is where Vacuum Metallising becomes the ideal substitute to getting the real chrome finish.
Dual has extensive experience in assisting with some of the biggest automotive names such as Jaguar cars, Land Rover, Bentley and Ford in achieving the desired effect for final model approval. Visit our gallery to view the Chrome Effect range.