Regarding classification of Surface Finishing & Electroplating
Chemicals
Circular
No. 16 dated 8th February 1994
I
am directed to say that doubts have been expressed regarding classification of
surface finishing and electroplating chemicals.
2.
The mater was referred to the Chief Chemist, CRCL, New Delhi for his
opinion in the matter. Chief Chemist, CRCL has stated (copy of the opinion
enclosed) that the technical information available reveals that various
substances or formulations are used for the treatment of the metal before it is
electroplated. The classification of these products or formulations depend on
their composition individually, for example pickling preparations fall under
38.10, polishing compounds fall under 34.05, and cleaning preparations
containing organic surface active agents under 34.02. The Chief Chemist, CRCL is
of the view that a general classification for all chemical
preparations/formulations used in the electroplating operation can not be given
as much would depend upon the actual chemical composition of the products, and
such surface finishing and electroplating chemicals should be classified
considering their composition.
3.
The opinion of the Chief Chemist, CRCL has been accepted by the Board.
Accordingly, it is clarified that the classification of the surface finishing
and electroplating chemicals may be decided on the basis of their chemical
composition.
4.
All pending assessments may be finalised on the above basis. Lower field
formations may be advised suitably. The trade may also be informed accordingly.
The
file has been referred to give my views on the classification of surface
finishing and electroplating chemicals.
According
to technical literature cleaning the surface of the metal is an important
process. This preplating treatment is necessary to the surface to accept an
adherent deposit. An ideal surface would be one consisting entirely of atoms of
the metal to be plated upon and having no foreign material at all. The cleaning
cycle includes: -
1.
Pickling to remove gross scale
2.
Mechanical preparation such as polishing and buffing
3.
Cleaning to remove oils, greases, shop dirt and polishing and buffing
compounds
4.
Rinsing
5.
Acid dipping to remove oxide films
6.
Rinsing
Formulations
for cleaning solution vary. These can be tailored to the specific conditions.
The
above technical information reveals the various substances or formulations are
used for the treatment of the metal before it is electroplated. The
classification of these products or formulations depends on their composition
individually for example pickling preparations fall under 38.10, polishing
compounds fall under 34.05, cleaning preparations containing organic surface
active agents under 34.02.
In
view of the above discussion, I am of the opinion that a general classification
for all chemical preparations/formulations used in the electroplating operations
can not be given, much would depend upon the actual chemical composition of the
products, and such surface finishing and electroplating chemicals should be
classified considering their composition.
|