2010-Aug-13

Anodizing and Coating with Experience

Chrome-Free Qualicoat-Approved Solutions for the Pre-Treatment of Aluminum

For many decades, hexavalent chrome pre-treatment has been the standard for aluminum. 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 equivalent to the "old" hexavalent chrome products. Users of chrome-free technology include all the world’s biggest names in the industry. Chemetall’s Gardobond® X and OXSILAN® AL series - state-of-the-art chrome-free pre-treatment processes for aluminum - help producers maximise adhesion and corrosion protection. Both Gardobond® X 4707 and OXSILAN® AL 0510 hold Qualicoat approvals.

Gardobond® X 4707

• Chrome-free solution for the pre-treatment of aluminum
• Spray, dip and cascade application
• Easy to handle
• Low maintenance process
• Easy waste-water treatment
• Easy on-line control
• Quantitative method for coating weight
• Range of industry standard approvals

OXSILAN® AL 0510

• Chrome-free multi-metal pre-treatment solution
• Spray, dip and cascade application
• Easy to handle
• Low maintenance process
• Easy waste-water treatment
• Easy on-line control
• Quantitative method for coating weight
• Range of industry standard approvals (including Qualicoat Approval for Powder Paint)
• Meets requirements of AAMA Spec. 2605 for Wet Paint

Chemetall helps meet the most demanding quality goals while eliminating heavy metals, thus reducing health, safety and environmental risks and costs.

Optimising the Anodizing Process with Gardo® TP 10748 and the Topseal Gardo® Series

Chemetall has now launched Gardo® TP 10748 – an additive for alkaline etching. This new product offers significant improvements for E-6 etching concerning

• rinsing and draining behaviour (i.e. low viscosity in the E-6 bath)
• homogeneity and matt finish (gloss readings 6 – 8 achievable, 60 ° test)
• increased productivity (batch optimisation)
• avoiding of surface defects caused by special alloy composition
• technical and economical aspects (i.e. less material removal)

Furthermore, Chemetall has given a lot of thought to the topic of hot sealing with the intention to minimise the problems occurring in daily operations and thereby to contribute to optimising process safety. These thoughts have led to Chemetall's new hot-sealing product series: Topseal. It comprises three different processes adapted to the customers' anodizing plants:

• Topseal Gardo® TP 10769: for use in baths without filtration
• Topseal Gardo® TP 10779: for use in baths with filtration through a filter pump
• Topseal Gardo® TP 10792/Gardo® TP 10793: for use in baths with filtration, optimised to reach longer bath life circles.

When optimally used, products of the Topseal Gardo® series achieve weight loss values of 10 – 15 mg/dm². Over the bath service life, this value rises appreciably less than with standard products.

All products can be analysed online or in Chemetall's laboratory. Chemetall Topseal reliably prevents the formation of sealing smut, gives clean, smut-free surfaces and offers benefits especially on coloured surfaces.

Borate-free Gardoclean® T 5281 Helps to Meet the Challenge of New EC CLP Regulation

According to the new European Commission Regulation No 790/2009, all mixtures containing borate must be re-classified as of December 1st, 2010 – all products containing 8.5 % (and more) of borax must be labelled with the skull and crossbones.

Most powder degreasers for anodized aluminum contain borate – and starting December 1st, 2010, these formerly harmless cleaning baths will suddenly be classified as toxic! Chemetall has the solution: Gardoclean® T 5281, a completely borate-free aluminum cleaner.

The product is liquid and thus easy-to-use, it provides good cleaning results also at temperatures below 60 °C (depending on condition of parts) and automatic dosage is possible.

Gardoclean® T 5281 has been specifically designed for cleaning aluminum both in the anodizing and pre-treatment processes.