Top brass
As it moves up the value chain, investment in equipment and training helps Pressure Die Castings exploit the advantages of brass for a demanding customer base, finds Alan Swaby.
Pressure Die Castings (PDC) is the largest company in its industry in South Africa, processing around 100 tons of brass and 20 tons of aluminium a month. The process of pressure die casting is a specialised operation. Working with molten brass at around 900oC (a temperature not much lower than the melting point of the steel dies themselves), the technique of pressure casting requires molten metal to be squirted into moulds at extremely high speeds and at pressures as high as 25,000 psi. Injection takes milliseconds, with the high speed ensuring that the brass doesnÔÇÖt begin to solidify before the entire cavity is filled.
Raw material is readily available as recycled scrap, melted down in PDCÔÇÖs primary furnace, analysed by spectrometer and then dosed to provide the correct alloy specification. From the primary furnace, molten brass is transferred to holding furnaces on each of the companyÔÇÖs 13 casting machines before being shot into steel dies and held under pressure until the brass solidifies. In the jargon of the business, shots are different from castings because there can be multiple cavities in a die, producing anything from two to 50 components at a time. The process is very quick, with each cycle requiring just 30 seconds, which goes a long way to explaining the monthly production capacity of two million at the Pietermaritzburg factory.
These days, very little is sold simply as raw castings, however. ÔÇ£Four years ago,ÔÇØ says managing director Mike Wolhuter, ÔÇ£we made a strategic decision to move further up the value chain. So most of the parts we make have some degree of value added. It could be as simple as fettling or buffing but it is more likely the work will involve machining and sub-assembly.ÔÇØ
The factory opened almost 60 years ago and has been in the hands of the current owners since the mid 1970s. During that time there has been regular upgrading of core machinery but the decision to provide an integrated service meant serious additional investment in sophisticated automated machine tools, capable of handling the volumes involved. The company has found that investment in the right equipment has made a significant difference to the quality of the products it produces. Innovating and investing in new processes and technology also helps it to stay ahead of both the local and global markets.
Brass is a desirable alloy because of its resistance to water corrosion, and it also has an attractive finish. PDC originally specialised in hardware items such as door and window furniture but the company has moved on from the supply of simple catches and handles to the casting of complete door lock mechanisms followed by machining and assembly.
PDC has also diversified its range of products to make full use of brassÔÇÖs conductive characteristics for the electrical industry and its water corrosion resistance for manufacturers of fire-protection systems. It also has a sister company established to handle aluminium die castings which supplies a tier one supplier to Ford Motor Company.┬á
Historically, customers have demanded quality and consistency, with rejection rates of less than one per cent. But now the company is working for the motor industry, the demand for quality control has jumped considerably, with reject rates of parts per million being the norm. ÔÇ£All the challenges that exist with this business,ÔÇØ explains Wolhuter, ÔÇ£stem from manufacture of the dies and how they cope with the high temperatures of molten metal. This is the area that calls for real skills and itÔÇÖs why we dominate the market.ÔÇØ
Naturally, a skilled workforce is essential and to ensure it has the best, PDC trains its own engineers and tradesmen. Currently the emphasis is on apprenticeships for the next generation of tool makers, fitters and electricians. But over and above that, successful companies take good care of the social needs of their workers. PDC has gone further than most by installing a clinic at the factory to administer primary health care. ÔÇ£HIV/Aids is such an endemic problem in this country,ÔÇØ says Wolhuter. ÔÇ£Those infected need regular and constant attention, which they receive from our clinic. But it does have a pay-off, with very low absenteeism figures amongst the 200-strong workforce.ÔÇØ
With a modern, clean production process, simply conforming to statutory requirements give PDC a tick in the green column. But as the cost of electricity rises, considerable effort has been put into mapping the entire energy usage of the factory; and external consultants have helped PDC to reduce its energy consumption.
In addition to its product and service offerings, though, PDC is essentially all about relationships. The company prides itself on offering a comprehensive service to its customersÔÇöpart of its competitive edge comes from its positioning as a ÔÇÿone-stop-shopÔÇÖ when it comes to meeting their die-casting needs. With a self-declared passion for problem-solving, PDC will work tirelessly with its customers until it can find an appropriate and suitable solution that will work for them.
Unlike some manufacturers today, PDC does not subscribe to the one-size-fits-all way of doing business. To the contrary, it takes its customerÔÇÖs specific needs as a starting point and develops personalised solutions which are then produced to the quality required. This approach to building and nurturing strong and mutually beneficial client relationships is undoubtedly a key factor in helping PDC to maintain its leading edge.
