The New Generation of Chrome Plating Solutions

ELECTROPLATING
JOT INTERNATIONAL SURFACE TECHNOLOGY
Specialist Finishing Company Opts for Hexavalent-Chrome-Free Process
The New Generation of Chrome Plating
Solutions
Trivalent chrome processes are the ideal alternative to hexavalent chrome plating and produce coatings
of a similar colour. The specialist finishing company Oberflächentechnik Döbeln has been using trivalent
chrome successfully for more than a year.
T
he German specialist finishing company Oberflächentechnik Döbeln
GmbH has been working successfully with a hexavalent-chrome-free coating process for over a year. The trivalent
chrome electrolyte (Surtec 883) is used
for chrome plating in shades of white.
For almost 20 years, Oberflächentechnik Döbeln GmbH has specialised in
applying metallic coatings using electroplating processes, together with the
accompanying pre-treatment and posttreatment phases.
The company’s 50 employees electroplate components for a variety of industries in its six fully automated machines. Four of these are responsible for
decorative chrome plating, which includes coating fixtures and fittings for
use in shops, kitchens and bathrooms.
The company has now coated 125,349
square metres of substrate using the
new generation trivalent chrome process, which is an area equivalent to
around 18 football pitches.
Converting the specialist finishing company’s machines.
Preventing yellowing
SurTec has many years’ experience of
trivalent chrome electrolytes and is an
approved supplier of trivalent chrome
coatings to Japanese and French OEMs.
An audit of the machines at the Oberf lächentechnik Döbeln site was carried out and the company modified
its equipment according to the recommendations in the audit. The conversion costs amounted to around 100,000
euros.
When production with the new
electrolytes began, the managing directors of Oberflächentechnik Döbeln
GmbH set themselves a number of ob-
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Example of an electroplated surface.
JOT International Surface Technology 1.2016
Service life of a mixed oxide anode during production five days a week and eight hours per
day, depending on the current density.
jectives. The appearance of the coating had to be similar to that of hexavalent chrome and it was essential to prevent yellowing. At the same time, the
machines needed to be 100% available
for seven days a week over three shifts.
Other goals included a maximum cycle time of seven minutes and a coating thickness between 0.1 and 0.3 µm.
JOT International Surface Technology 1.2016
SurTec 883:
L = 82.20 / a = -0.42 / b = 0.06
Hexavalent chrome: L = 80 to 84 /
a = -0.5 to -1 / b = -0.5 to -1.4
A much larger area can now be
electroplated per 10,000 Ah than was
previously the case. The new process can coat up to 430 m² compared
with 100 to 200 m² with the old one.
A single-sided coating with mixed oxide is also possible. The company has
achieved its original objectives of seven-day-a-week availability in threeshift operation, together with current
densities of 3.5 to 5.0 A/dm² and coating thicknesses between 0.1 µm and 0.3
µm within four minutes. Close to the colour of hexavalent
chrome
After over a year of production using
the new system, the results are positive. The colour of the coating is stable and very close to that of hexavalent
chrome, as shown by colour measurements using a Konica Minolta d 700 after 13 months of production:
Contact:
SurTec International GmbH, Bensheim, Germany,
Tel. +49 6251 869520, [email protected], www.surtec.com
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