When you buy a new car,
you expect it to be equipped with the latest technology: navigational system,
power everything, alloy wheels, etc. However, you customize it with options that
harmonize with your driving style. This may include leather seats, multiple CD
player and a sunroof. You don't simply buy it off-the-shelf as you would a power
saw or pack of light bulbs. You want the newest and the best, tailored to your
transportation and personal requirements.
So it was at Hansgrohe, Inc. (Alpharetta, GA) when it decided to install a plastics
plating line. The 100-year-old German company had ventured in the United States
five years earlier, establishing a distribution facility in Georgia for its kitchen
and bath fixtures. Gradually the company added assembly and eventually manufacturing
as its U.S. business grew. Plating the ABS plastic showerheads molded at the company
was a logical step in the company's growth.
Installing the new line was all part of Hansgrohe's plans for better quality control
over its products. It started when the company began molding its own plastic components.
Not only does it mold the ABS plastic pieces that are plated, but it also molds
the internal components. By doing the molding in-house, the company has control
over keeping the molds' surface highly polished. This eliminates any flow lines,
parting lines, or pores that could affect subsequent plating.
 |
| Processing is
programmed according to the number and type of parts.
|
The first finishing operation
installed at the company was physical vapor deposition (PVD). This process is
applied to both metal and plastic parts. A decorative "polished brass"
finish is applied to showerheads and faucets. Parts are loaded into one of two
vacuum chambers. A benefit to having two units is that one can be used for metal
and the other plastic, as they run at different temperatures. The units are vertical,
with the target source in the center. Parts are racked so that they revolve around
the target source. Deposition rates are rapid. Film thickness ranges from 300Å
to a few mils, depending on specifications.
Even though PVD was available
in-house, parts were sent out to job shops for plating. The parts were plated
acceptably, but the company wanted more control over the process. That was when
it decided to bring plastics plating in-house. The company did not simply purchase
plastic plating equipment and chemistry off-the-shelf, however. Kevin Wynschenk,
plating manager knew that for Hansgrohe to maintain its reputation for quality
and keep growing, it needed the best plastics plating technology on the market.
 |
| Plated plastic
showerheads are finished with nickel chromium and PVD.
|
First he looked to the
parent company in Germany to observe its manufacturing and plating methods. However,
its plating operations were not the newest and the best for Hansgrohe's operations
in the United States...at least as far as Mr. Wynschenk was concerned. He wanted
to tweak the plating lines to suit the Alpharetta plant's operations. Also, the
chemistry was traditional plating on plastics chemistry, and he knew that there
were newer, more efficient products on the market. The plan was to integrate the
equipment with a newer plastics plating chemistry.
Although Mr. Wynschenk was comfortable with the ins and outs of decorative nickel
chromium plating on metal since he had worked in plating shops for several years,
he wasn't as familiar with plating on plastics. He understood the basic technology,
but relied on his supplier, Enthone Inc., to ensure that the process fit with
the growth and quality image Hansgrohe was establishing in the U.S. Enthone was
up for the challenge, particularly since this would be the first U.S. installation
using its new Ionogen and Monolith(r) plastics plating technologies.
First, Hansgrohe worked with LPW Equipment to design the new plastics plating
line for growth. Even though space was limited, several gaps were left in the
U-shaped line in anticipation of additional plating and rinse tanks.
The chemistry integrated into the plating line also allowed for a smaller equipment
setup and less investment, since less tanks were needed, even though throughput
could be increased up to 15% compared to line running traditional chemistry. Fewer
tanks are needed because no hexavalent chromium is used in the activator step.
There is no need for a neutralization step to reduce the hexavalent chromium to
trivalent chromium. Parts are transported directly into the accelerator. Also,
no copper is used on the line, eliminating the need for copper plating tanks.
Because there are less tanks and fewer plating processes, it naturally follows
that throughput is increased.
 |
| The plating sequence
at Hansgrohe uses electroless nickel. It has found that an all-nickel system has
several advantages over one using copper.
|
The crossbar of the U serves
as the transfer station on the line. The line is fully automated, with operators
simply having to use a touch screen to identify the parts and quantity. The system
automatically does the rest, controlling amperage, tank time, current density,
solution level and temperature. Some chemical additions are also automated, such
as nickel brighteners, carrier and electroless nickel additives.
Special features of the plating equipment include a special rinse station at the
end of the product line. The Kavitec rinsing system has bars that cycle up and
down with jetties to force water into recessed areas of the parts. The drying
system, Boratec, is set up in a similar fashion using hot air. The air jets can
be individually programmed to cycle on and off, or pulse, for a programmed period
of time. "It makes for much more thorough, spot-free drying," commented
Mr. Wynschenk.
But the plastic plating chemistry is what is really unique to Hansgrohe line.
"At first we did simply install the supplier's standard technology,"
stated Mr. Wynschenk. "But we soon found that even the newest and most advanced
technology needed to be tweaked to fit our process, products and ideas of how
things needed to be done." Once the plating chemistry was "in place,"
full production began.
A typical cycle begins after parts are molded and cured for 48 hrs. The first
step in the plating process is an etchant specially designed for use with ABS
plastics. The etchant uses sulfuric and chromic acid and water as well as 10 mg/liter
of palladium to prepare the plastic surface for an activator step that follows.
The activator also uses sulfuric and chromic acid and palladium and is specifically
developed for ABS plastics. Parts processed in the solution acquire a fine dispersion
of palladium that is diffused in the etched plastic surface. This palladium catalyzation
initiates nickel deposition when the parts enter the subsequent electroless nickel
solution.
However, parts do not go directly from this step into the electroless nickel.
 |
| Hand-held shower
massagers come in a variety of finishes. All plastic parts are plated without
using copper.
|
There is one more step
prior to electroless nickel plating. Parts are first immersed in an accelerator
that reduces palladium diffused on the surface. This ensures that the electroless
nickel deposition will be fast and uniform.
The electroless nickel was not part of the original "standard" plastic
plating system offered. However, the original offering did not work with Hansgrohe's
system. After much experimentation and long hours, the suppliers and plating technicians
at Hansgrohe came up with the electroless nickel solution. "Using an all
nickel system instead of copper has several advantages," noted Mr. Wynschenk.
"The biggest advantage is in the waste treatment area. Because our wastewater
isn't contaminated with copper, we can separate our streams into one for nickel
and one for chromium and recycle it. We also benefit because the finished product
has a much harder finish than if we had used copper. We have run a number of performance
tests, such as neutral salt spray and wear resistance tests, and the all-nickel
process outperforms the copper." The all-nickel system also offers improved
thermal shock performance, an important attribute when considering the nature
of Hansgrohe's products.
The only disadvantage of note, as Mr. Wynschenk sees it, is that you have to start
with a "perfect" part. "Copper has the ability to cover flows lines,
pits and other imperfections. But since we have control of the molding process,
that isn't really a problem here at Hansgrohe," he noted.
|
TABLE
I-Plating Processes |
| Process
|
Temp.
(F)
|
Time
(min)
|
Sp.
Gravity
(at 68F)
|
Agitation
|
pH
|
Etchant
(Udique BL 2010) |
160
|
10-20 |
1.450 g/cm ³
|
air/cathode
rod
6-9 fpm
|
|
Activator
(Udique BL 2110 MS) |
ambient |
3-5 |
1.016
g/cm ³ |
air-cathode
rod
6-9 fpm
|
|
Accelerator
(Udique BL 2210) |
90 |
3-5 |
0.947
g/cm ³ |
no
air/work movement 7-12 fpm
|
|
Electroless
Nickel
(Udique 891) |
85 |
6 |
|
mechanical
|
6.5
|
Electrolytic
Nickel
(Elpelyt Monolith) |
117 |
1
µ/min |
1.35
g/cm ³ |
vert/horz
work movement or air
|
9 |
Bright
Nickel
(Elpelyt LS 1) |
140-144 |
1
µ/min |
1.20
g/cm ³ |
vert/horz
work movement or air
|
3.8 |
Nickel
Activator
(Ankor NFDS) |
ambient |
40
sec |
1.0
g/cm ³ |
none
|
4.2 |
Bright
Chromium
(Ankor 1120 H) |
105 |
4.7µ/min |
1.125
g/cm ³ |
|
|
The electroless nickel process deposits a smooth, continuous coating on the activated
plastic showerheads and faucets. It is a low-temperature operation, running at
about 90F. Electroless nickel plating is followed by the "Monolith"
prior to bright nickel plating.
 |
| Hansgrohe also
manufactures and plates faucets for kitchens and bathrooms.
|
The Elpelyt Monolith electrolytic
nickel-plating process for plastics is a multiple-additive nickel process that
also serves as a substitute for the copper in the plating process. The nickel
deposits are ductile, which is important for these products, considering the subsequent
assembly they go through. After the plating process is complete, additional plastic
components are added to the interior of the parts, along with hoses and fittings.
Also, additional exterior parts are added such as nozzles, sprays and adjustment
components, such as those used to reconfigure the spray pattern for normal spray,
soft spray or a massage spray.
The next step is bright nickel plating in Elpelyt LS 1. This is a multiple additive
bright nickel plating process that provides for excellent chromium receptivity.
Following that is a nickel activator prior to chromium plating.
The electrolytic (cathodic) activator replaces activating parts in sulfuric acid,
thus preventing milky chromium films and stains that can result from passive bright
nickel deposits due to insufficient rinsing or prolonged periods between nickel
and chromium plating.
The final plating process is bright chromium plating with Ankor 1120 H. This process
is based on a mixed acid chrome electrolyte. It provides excellent coverage over
a range of operating current densities. Despite lower concentrations of chrome
versus a conventional chrome plating solution, this process offers good tolerance
to contaminants while also providing improved throw and coverage.
The bath is followed by the Kavitec rinse cycle and Boratec drying system described
previously.
Once plated, parts are sent on for in-house assembly and packaging. Hansgrohe's
parts are sold in stores such as Home Depot under the name Monsoon, among others.
One of the interesting aspects of the company is that it allows you to try out
its high-end products prior to purchase. You can shower at the facility in Alpharetta
under a number of different shower panels. There are panels that have hand showers
and body showers and temperature controls with integrated thermostats so that
when someone starts the washing machine you aren't scalded or left with goose
bumps! These are just some of the products Hansgrohe has developed.
The company is constantly developing and broadening its product line. In June
the company plans to triple the capacity of its plastics plating line. It will
also add another plating line for plating brass faucets with a "brushed nickel
finish." "This will bring more of the plating in-house and give us more
control over quality," said Mr. Wynschenk. "Of course we will also have
to expand our waste treatment facility to handle the expansion. We are currently
only using about 4,000 gpd."
What really sets Hansgrohe apart, however, cannot be derived from a list of features,
processes or marketing claims. It is the feel of the product that makes the difference.
It is a feel of surpassing excellence, of superb fit, finish and function . .
. a feel that makes the shower the best part of the day.
