Distortion During Chrome Plating of Plastic Parts
We are trying to chrome plate (bright and satin finishes) the plastic housing of a rear view mirror on a car. We are using a plateable grade of ABS but are experiencing quite a lot of distortion of the parts during the plating process. Any advice on how to reduce this distortion would be helpful, i.e., material selection, processing details, etc.
Standard plating grade ABS plastics have heat distortion temperatures of around 80 deg C.
First of all make sure your Etch is running at the correct temperature (around 67 C). None of the other baths should be this hot in a plating on plastics line so shouldn't be causing any problems. Make sure your tension on the rack tips is set just enough to hold the parts on in process. Sometimes it pays to use more contacts per product, lessoning the load on the individual contacts.
In terms of material types the next material I would be tempted to try would be a polycarbonate/ABS blend. They should run through your line (if the polycarbonate content isn't to high) without any modifications to the process. This material offers heat distortion temperatures around 110 deg C and is very similar to straight ABS to mould.
Hope this helpsTim Strickland
- Auckland, New Zealand