WCA September 2012

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Dies, lubricantsand drawing
84 Wire & Cable ASIA – September/October 2012
Historically the wire drawing industry in many parts of Asia
has chosen to use relatively low technology lubricants
for rod breakdown applications, the decision on which
product used being based largely on unit cost per litre/
kilo of the lubricant rather a consideration of the ‘total
cost of production’ which is the normal approach in more
developed markets.
There is no such thing as the perfect lubricant. If there were
it would be the case that it was extremely low cost, only
very little of it would be used and it would never have to be
changed. In reality this can never be the case. In virtually
any production process the only reason a lubricant is used
is to make the process run – without the lubricant the
ultimate final product cannot be manufactured.
In the case of wire drawing lubricants this logic is
equally true, but it is important to move to a ‘total cost of
production’ concept rather than simply looking at the unit
cost of the lubricant when justifying the lubricant to be
used. For wire drawing companies major running cost items
include:
• The cost of copper/copper rod
• Poor control of manufacturing tolerances
• Dies
• Energy
• Surface coatings
• Maintenance costs
• Scrap/reject/machine downtime
• Labour
• Waste disposal
Considering most of these individual areas of cost, the
amount spent on production lubricants is considerably
lower. When these areas are considered as the total cost,
the lubricant represents only a very small fraction of this
figure and yet performance of the lubricant can reduce costs
in many areas of the production process and lead to an
overall ‘total’ cost reduction.
As some specific examples in relation to rod breakdown
lubricants:
1 Copper/copper rod/quality
It is universally accepted that the quality of copper rod
directly influences the quality and efficiency throughout
all stages of the wire drawing process; and also quality
of the final product produced.
2 Control of manufacturing tolerances
In the same way that input rod quality is important at
every stage of the drawing process, it is the quality of
the wire produced from the rod breakdown machines
which govern the quality, efficiency and amounts of
reject material produced during subsequent re-drawing,
and then final processing operations (eg enamelling,
insulation, cable production, etc).
Obtaining the correct balance of levels of lubrication with
properties such as detergency, wetting characteristics
and long-term emulsion stability is essential and leads
to a high degree of technology and complexity in the
lubricant formulation.
3 Lubricant consumption/top-up
As stated, purchasers often focus on the unit price of
the lubricant when re-charging a lubricant system as it is
obviously a significant cost, particularly for large volume
rod breakdown systems.
The true cost of the lubricant actually should be
measured over the lifetime of the lubricant against the
tonnage of copper produced. The obvious example
of this is the amount of top up of fresh lubricant that is
used per tonne of copper wire produced. The total cost
of fresh lubricant added on a daily, weekly or monthly
basis can often be greater than the quantity used initially
to charge the lubricant system.
Differences between high and low quality lubricants in
amount of top up used can vary massively. High quality
lubricants typically will require in the order of between
0.25 and 0.75 litres top up per tonne of wire drawn for
rod breakdown (figures vary because of other factors
such as system size, rod and die quality, filtration quality,
water quality, etc). Some ‘good’ systems will even use
less than this.
Lower quality products on the other hand could require
10 to 20 times the amount of top-up lubricant. Whilst
higher technology products may appear expensive in
terms of unit cost, over the longer term they can and
often do show actual cost savings purely on the amount
of lubricant used over the lifetime of the lubricant
system. The reasons for this are generally quite complex
but relate to a large extent on factors such as emulsion
stability and reactivity of the lubricant to the copper
itself.
4 Associated product costs
In basic terms the lubricant is designed to produce high
quality wire and protect the dies and capstans from
excessive wear. Lubricant formulation development does
not stand still and formulators are constantly striving for
formulations which give better performance regarding
these functions. As before, simple logic would say that
some lubricants are better than others in the way they
perform – and therefore improved die and capstan life
are achievable as well as reductions in the amount of
maintenance required re die cleaning, re-polishing or
replacement. It should not be forgotten that maintaining/
replacing die sets – particularly if not done in a planned
manner – leads to lost production and therefore
increased cost. The same applies to any down time or
stoppages in production, for example wire breaks.
Batoyle Ltd – UK
Agent: Ajex & Turner – India
Website:
Drawing down the costs
❍ ❍ The Mastersol range of speciality wire drawing lubricants from
Batoyle