Parameter optimisations for gold electroplating of gold jewellery

The purpose of this research is to reduce the over-specification of thickness in electroplating process of gold jewellery using experimental design for analysing optimisation of parameter conditions affecting thickness of gold jewellery in electroplating process and finding optimisation for controlling specification and reducing average thickness. The factors were electroplating period, gold concentration, the electric current and the electroplating temperature. Each factor had two levels. There were four responses collected, that were average gold thickness (Y1), minimum value of gold thickness (Y2), standard deviation of gold thickness (Y3) and average of gold on stainless steel sheet (Y4). 0.05 significance level was used. The results showed that the appropriate parameters were 17 minutes of electroplating period, 0.4 gram per litre of gold concentration, 0.6 amperes per square decimetre of electric current and 60 degree Celsius of electroplating temperature. The experiment could reduce the electroplating period by 4.20 minutes, the average gold thickness jig by 0.13 micron, minimum of gold thickness by 0.19 micron, and average gold percentage by 3.91 percent. These results reduced specification from maximum value of thickness from 3.75 micron to 3.55 micron and mid-thickness average from 3.50 micron to 3.45 micron.