TPT January 2011

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40 January 2011 ›
Technology Update
Anodising
and coating
AT the 2010 Aluminium Trade Fair in
Essen, Germany, Chemetall showcased
its Gardobond® X and Oxsilan® AL products
– new chrome-free solutions for the pre-
treatment of aluminium, and the Gardo®
TP 10748 and Gardo Topseal products
for anodising processes, as well as the
completely borate-free aluminium cleaner
Gardoclean® T 5281.
For many years, hexavalent chrome
pre-treatment has been the standard for
aluminium. More recently, chrome-based
pre-treatment processes have come under
pressure for environmental and health and
safety reasons. The first chrome-free pre-
treatment processes started to appear in
the marketplace about 20 years ago.
Today, with almost two decades of
operating experience gained, and hundreds
of users worldwide, the performance of
these programmes is said to be equivalent
to the ‘old’ hexavalent chrome products.
Chemetall’s Gardobond X and OxsilanAL
series chrome-free pre-treatment processes
help producers maximise adhesion and
corrosion protection. Both Gardobond X
4707 and Oxsilan AL 0510 hold Qualicoat
approvals.
Gardo TP 10748, an additive for
alkaline etching, offers improvements
for E-6 etching concerning rinsing and
draining behaviour (ie low viscosity in the
E-6 bath), homogeneity and matt finish
(gloss readings 6-8 achievable, 60° test),
increased productivity (batch optimisation),
and avoidance of surface defects caused by
special alloy composition.
Chemetall’s new Topseal hot-sealing
product series consists of three different
processes adapted to users’ anodising
plants: Topseal Gardo TP 10769 for use in
baths without filtration; TP 10779 for use in
baths with filtration through a filter pump;
and TP 10792/TP 10793 for use in baths
with filtration, optimised to reach longer bath
life circles.
When optimally used, products of the
Topseal Gardo series are claimed to achieve
weight loss values of 10-15mg/dm².
All products can be analysed online or in
Chemetall’s laboratory. Chemetall Topseal
prevents the formation of sealing smut,
gives clean, smut-free surfaces and offers
benefits especially on coloured surfaces.
Chemetall’s Gardoclean T 5281 is a
completely borate-free aluminium cleaner.
The product is liquid and so is easy-to-
use. It provides good cleaning results at
temperatures below 60°C (depending on
condition of parts) and automatic dosage
is possible. Gardoclean T 5281 has been
specifically designed for cleaning aluminium
both in the anodising and pre-treatment
processes.
Chemetall GmbH – Germany
Fax: +49 69 7165 3428
Website:
Clear Gardobond X 4707 bath