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Improving productivity and efficiency in diecasting

With increased global competition driving the search for production efficiency improvements in the diecasting industry, Tim Butler of Ultraseal International Group discusses how innovations in die release agents and spray technology can support manufacturers to improve productivity, efficiency and competitiveness.

In today’s diecasting industry cost optimisation, improving productivity and output quality are key drivers, particularly in the face of increased global competition and the need to produce ever-more complex components. It is these factors in particular which have encouraged foundries to look for new solutions which enable them to produce high-quality, complex, cast components whilst reducing costs and improving production operations.

Developments in the automotive industry have led a shift in diecasting towards more complex, lightweight, components in powertrain, chassis and structural parts. The growth in chassis and structural parts in particular has led to investment in larger high pressure diecasting machines and more expensive tooling. This development has subsequently shone a light on all aspects of diecasting operations, even down to the role of the die release agent used, as manufacturers look to improve levels of productivity, process reliability, output quality and increase die life.

To understand how the choice of die release agent can significantly contribute to enhancing production efficiency, cost reduction and business success, it’s worth taking a look at the advantages new technology can bring.

Efficiently maximising coverage

If we think about the main purpose of a release agent – to facilitate clean part release and provide a release film to prevent die soldering – achieving uniform coverage is critical to both process reliability and the overall quality of the final product.

The use of traditional water-based lubricants sees the liquid evaporate when it comes into contact with the hot steel die, leaving an amount of lubricated coating. This is a critical stage as too much lubricant means the liquid cannot evaporate fast enough when the molten metal is injected; while too little lubricant could result in poor material flow or die soldering, ultimately causing surface defects and porosity, compromising the overall quality of the part. As the industry evolves to meet current demand for complex single piece components, die complexity is making this issue increasingly prevalent as manufacturers face the challenge of achieving a consistent level of lubricant coverage across the entire mould. This includes cavities where excessive amounts of water-based lubricants typically remain, causing cold flow, porosity and staining on the casting surface.

The solution to this problem lies in electrostatic spray technology. Developed by Lubrolene, WFR-EC has an electrostatic charge added to the die release agent which, when applied through a specially developed electrostatic spray gun, creates a wrap-around effect and ensures uniform coverage of the release agent, irrespective of die complexity. The application of Lubrolene WFR-EC through electrostatic spray further reduces soldering problems and facilitates a move away from water-based lubricants to ensure greater, and more consistent, levels of quality in die cast components.

The addition of electrostatic charge to Lubrolene WFR-EC also dramatically improves adhesion properties and provides more consistent oil film formation – critical in achieving uniform die coverage and a smooth release. Beyond benefits around quality, greater percentage levels of adhesion lead to reduced material wastage and improved cycle times.

Typically, applying a water-based die release agent with an air spray gun achieves just four per cent adhesion efficiency. Using Lubrolene’s specially developed spray gun technology improves the efficient application of Lubrolene WFR-EC and achieves >80 per cent adhesion efficiency when compared to traditional water-based die lubricants.

Increasing process speed with reduced spray time

When looking to improve the efficiency of a process, it is often easy to overlook stages which have always been executed in a particular way. In diecasting, the application of die lubricant is one such example. As a short-cycle and repetitive process, the saving of just a few seconds in the diecasting process can lead to significant time savings and impact directly on productivity and costs as long as the tool has been designed accordingly.

If we look at standard air spray application guns, they need to spray from multiple angles to deliver full die coverage and adhesion. In practice, that takes time and can compromise quality with uneven levels of coverage – particularly in more complex moulds. By using electrostatic attraction, however, the Lubrolene electrostatic gun can uniformly cover and adhere to a much broader area, without the need to spray from various angles.

With typical spray time – even for the largest >4,000 tonne machines – being between just seconds with Lubrolene WFR-EC and specially-designed Lubrolene spray heads, spray time can be significantly reduced. That means reduced cycle times, increased throughput and greater productivity can be achieved. Furthermore, with Lubrolene die-spraying equipment being modular in design, it can be easily adapted to suit any size of diecasting machine, while its low-maintenance design improves reliability, bringing about potentially significant benefits for the diecasting industry.

Increasing uptime and reducing costs through extended tool life

While quickly maximising die coverage can help manufacturers to realise greater levels of efficiency and productivity, there is a further benefit to Lubrolene WFR-EC which perhaps holds the most significant results – extended tool service life.

The use of traditional water-based release agents gives rapid die-surface cooling, leading to extreme temperature fluctuations which can quickly lead to the formation of cracks on the die surface as a result of repeated compressive and tensile stresses. With cracks typically starting after several hundred shots, this reduces the tool’s service life to <120,000 shots for a typical diecasting machine.

Thanks to its very small spray amount, the rapid cooling effect prevalent in traditional methods is significantly reduced when using Lubrolene WFR-EC, almost eliminating the thermal stresses which dies would typically be subjected to. With this contributing to extending service life by up to six times, cost savings can be more than €500,000 per annum. Extended service life has in another installation also meant fewer tools are required, delivering further programme cost savings of up to 20 per cent.

Overall, Lubrolene WFR-EC supports manufacturers within the diecasting industry to work more effectively towards meeting their challenges of increasing output and production efficiency and delivering cost savings while producing more complex components that meet industry demands. Increased spray application speed means a significant reduction in cycle time; more uniform adhesion brings about greater levels of process reliability and reduces material waste; and reduced stress on die tools dramatically increases service life. The results of these core benefits are clear to see, making productivity improvements and cost savings achievable for the high pressure diecasting industry, without the need to compromise on quality.

Contact: Ultraseal on Tel: on +44 (0) 24 7625 8444  web: www.ultraseal-impregnation.com