In the “Plating on Plastics” process the bonding of the metal to polymer takes place at a molecular level, the quality and surface finish of the plastic moulding is extremely important as it will be reflected in the final product. Unwanted features such as “sink”, “flow lines” and “weld lines” become magnified by the high gloss surface of the plating. Defects in the polymer surface, such as “silvering” due to insufficient drying of ABS and PC/ABS, “cold slug”, “high stress” and excessive pigment, can cause the plating to blister, as the conductive nickel coating will not bond in these areas.
The design of the moulding effects its ability to be electroplated. Features such as blind holes (which entrap the plating chemicals), sharp corners (which can cause excessive metal build up) and sharp groves or raised sections (which can lead to “Faraday Cage” effect preventing plating in that area) should be avoided. It is also essential that, if there is not an obvious location, provision is made or the jigging of the component, such as the addition of a “Plating Peg” or leaving the feed sprue attached.
The correct packaging of the mouldings is as important as that of the plated item, as a scratched or dented moulding will result in a shiny scratch or dent on the finished product. Mouldings should not be packed in plastics bags until at room temperature to prevent surface contamination from release agents.
We would always recommend the use of “plating grade” natural materials and the optimum moulding conditions, for the best quality finish.