Non-toxic chrome-free bonding

Henkel has developed BONDERITE M-NT 2040 R2, which is formulated using only non-toxic, chrome-free components.

This product not only offers the potential for shorter process times, but does not produce any effluent that requires treatment.

Furthermore, it is suitable for dip and spray processes, and is both GSB- and Qualicoat-approved.



Given the many statutory requirements governing environmental protection and occupational safety – such as RoHS, WEE, REACH and ELV regulations – BONDERITE M-NT 2040 R2 constitutes a viable alternative to traditional chrome-VI conversion treatments.

It offers good welding and adhesive bonding properties for uncoated aluminium surfaces, as well as creating an optimal layer on the substrate for subsequent coating.

Importantly, the BONDERITE M-NT 2040 R2 non-chromic process combines both etching and passivation effects. It thus enables the number of process baths to be decreased and pre-treatment lines to be reduced in length.

In fact, if using an alkaline degreaser, it is possible to eliminate the etching tank altogether, which currently cannot be achieved using any other product on the market.

Rinse or multiple rinse stages can also be eliminated, while a DI (deionised water) rinse can be replaced with a conventional tap water rinse in some applications.

As it contains a small quantity of surfactant, BONDERITE M-NT 2040 R2 can be used as a cleaner-coater, effectively replacing conventional degreaser products.

At a customer in Europe, this allowed an existing pre-treatment line to be reduced from six tanks (alkaline degreaser, rinse, rinse, Chrome-VI, rinse, DI rinse) to just four (cleaner-coater, BONDERITE M-NT 2040 R2, rinse, DI-rinse), thus boosting productivity significantly using a non-chromic process without any detriment to performance.

Another benefit is that existing green chromating lines can be converted to the new BONDERITE process without modification to the active baths.

Moreover, it can be used at room temperature (around 25°C), leading to significant energy cost reductions, while both water and wastewater are likely to be reduced by up to 70% due to fewer baths.

BONDERITE M-NT 2040 R2 is also suitable for multi-metal lines. With this in mind, adoption of the product can help plants transform from a facility suitable only for aluminium, to one that is capable of processing multiple metal types.