WCA September 2012

Dies, lubricants and drawing

Drawing down the costs

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. ❍ ❍ The Mastersol range of speciality wire drawing lubricants from Batoyle

Batoyle Ltd – UK Agent : Ajex & Turner – India Website : www.ajexturner.com

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Wire & Cable ASIA – September/October 2012