If the finish you want can be painted then it will probably be cheaper to add pigments. This will be far the cheapest method unless you are from a low wage area.
If you require a "Chrome Plated" finish then you will have to, er,... chrome plate them. This gets v. expensive as few platers of plastics exist (only 2 in the UK), the fallout rate from the plating is around 20 percent, and then there is the transport back and forward.
Metallic finishes in plastics are produced by adding aluminium flakes - size and geometry of your choice. Weld lines may a problem - the finer the flake the worse it looks. Base polymer is important. Works well in transparents and transucents, (e.g. PC/PS, and PP et.al.)not very good in opaques (e.g. ABS/Nylons/anything filled, etc.)
Suppliers of raw flake include Eckart (Germany)and Silberline (UK), both have worldwide distribution. Any good masterbatch supplier will be able to give you what you require.
Thanks for the quick reply Pad,
Sounds like you agree that post paint is the most cost effective way for metallic finish. We are based in tha USA and were always told that it was really hard to mold with aluminum flakes due to cosmetic issues, just like you mentioned.
On the other hand, I look at my laptop casing and it's got this metallic look to it, and it's cosmetically appealing alos, I wonder how they manage to do this.
I think this is an interesting topic in plastics and has got a lot of opportunities for improvement. Any feedback is highly appreciated as I am very interested in the development of this -paint -plastic method(s).
Depending on your design and where the part is gated, it is possible to get a moldable part that is very appealing and this would be the less expensive means of manufacturing the part, unless you are looking at manufacturing in China with very low labor cost, then you may want to consider painting. We have just completed a program of manufacturing a new electric razor in the United States, and the base material is a clarified ABS and the color is a metalic grey. The processing is critical to the part looking good, but there are materials now available to make the part look more uniform in appearance. You may want to contact a colorant house such as Clairiant.
