We wish to bring to your notice some salient features NALSUN Coating.

NALSUN technology involves selective black Chromium coating in a special room black Chromium bath at normal Chromium plating densities (other such formulations involve costly refrigerated baths since they are done at 3 to 4 times the normal Chromium plating current density). The obvious advantage of this process is lower cost and higher productivity which we are passing on to our clients.

Apart from this, another feature not commonly found in black Chromium bath enhanced covering power. Even copper can be directly plated with black Chrome from this bath which is not possible in the case other conventional black chromium baths. Normally Nickel undercoat will be needed to plate on copper. Our specially formulated Catalysts confer this properly.

The coating obtained from NALSUN black Chromium bath has an absorbivity of 96% and a high alpha epsilon ratio (S). Unlike the other Chromium processes NALSUN black Chromium does not decrease with usage and it’s alpha epsilon ratio remains high and constant.

Thermal stability of NALSN coating is reliable and good. Recrystallisation of the amorphous optical composite sets in at 450 C. Thermal cycling between room temperature 300C does not affect the alpha epsilon ratio. The adhesion of the deposit is excellent. Internal stress is low. Hence, the deposit does not crack and peel off during cold forming of black Chromium plated Copper which is otherwise practiced by solar collector fabricators.

In the as-plated state the deposit is crack free and hence corrosion protection is not lowered. The deposit is hard and abrasion resistant.


Absorptitivity (a) Alpha = 0.96 + 0.02

Emissivity (e) Epsilon = 0.12 + 0.02