Core values

Posted on 15 Jan 2008 by The Manufacturer

Ross Ceramics is intent on raising capacity to meet growing demand. Operations director Tony Cox puts Robert Pols in the picture

The key to efficient performance is an empty space, and engineering that space is an undertaking of some complexity. It’s to help complete this undertaking that Ross Ceramics deploys its ceramic cores technology.

To be efficient, jet engines must operate at high temperatures, and this makes extreme demands on the materials involved. That’s why the turbine blades are cast with a hollow core, which allows air to pass through and keep them cool. But each blade has a twisted aerofoil shape, so there’s a complex geometry to its internal air passage, and that is formed by a precisely contoured ceramic core that is set at the heart of the blade and then, effectively, dissolved after casting.

These cores are used in the investment casting of gas turbine engines for aerospace and industrial applications, and are the province of Ross Ceramics, a wholly owned subsidiary of Rolls-Royce. The business has more than 35 years’ experience in this specialist field and employs around 350 people. It operates from a well-established site in Denby in Derbyshire, and a facility in Trentham, Staffordshire, which opened in 2005.

The customer defines the cooling passage that is required, and the company produces a core around which the metal can be cast. But the concern isn’t solely with shape. Once in the furnace, materials must perform in controlled and predictable ways: they must have dimensional consistency, they must offer the appropriate degree of refractoriness, and there must be no core-to-alloy reaction. So an extensive understanding of materials is needed, and they must be tailored to the specific requirements of customers’ individual casting processes. Understandably, therefore, Ross is constantly working to develop new ceramic formulations, blending its raw materials on site and undertaking full testing for properties and performance.

The demand for products is healthy, as operations director Tony Cox explained: “We’re currently making a number of cores for the Rolls-Royce Trent 900 engine, which goes into the A380 double-decker Airbus, and for the Trent 1000, which powers the Boeing 787. Then, we hope, the next big project will be for the extra-wide-bodied Airbus XWB. Production hasn’t yet started, but Rolls-Royce took a good number of orders for the XWB at the Paris and Dubai air shows this year. So that offers prospects for our aerospace division, managed by Joe Barker. In addition, there’s significant growth in the industrial gas turbine market.”

When Cox took up his post in June, he inherited an operation already firmly committed to improvement. The new Trentham facility had been laid out from the start with cellular manufacturing in mind, and attention was now being turned to the Denby plant. Work at both sites had already benefited from applying the DMAIC principles (define, measure, analyse, improve, control) that are crucial to both six sigma and the Rolls-Royce production system. But that still left him with further improvements to strive for.

“What we’ve focused on during these five months,” he said, “are flow and compliance, and we’ve now set up teams to look closely at both of those areas. We’ve tried to improve the flow of our products – particularly at Denby, which lacks Trentham’s advantage of being a newer and better laid-out facility. I’m keen to reduce scrap and to ensure we’ve minimised the route that a product takes through the factory. We’ve also been looking at compliance, because some of our processes are very heavily reliant on the individual operator.”

In fact, he continued, encouraging results are already being achieved. “In terms of yields, we are starting to see an improvement of four to five per cent, and I’d like to reach between eight and 10 per cent by the year’s end. There are also gains in terms of flow, and the weekly output in one industrial gas turbine area is up by 70 to 80 per cent.”

The coming year, he added, will see the momentum for improvement continue. “For me, only five months into this new role, there’s still much to learn about the business and the industry. But I believe the next 12 months will be key for us in our work on product flow and compliance. The future is very much about standardisation and about establishing processes that are less operator-dependent. Much of our work is very labour-intensive, particularly in the finishing part of the core-making process. We’re looking at that in the context of our pursuit of process excellence, and we need to reach the point where we’ve automated as much as we can, thereby raising the level of repeatability and ensuring consistently high yields.”

The challenges facing operations are just part of the challenges that await the company as a whole, and the drive to make air travel more energy-efficient is creating its own imperatives. “As the pressure to find more spectacular alloys continues, so we need to be casting at higher temperatures,” Cox explained. “Then there’s the fact that the industry as a whole can expect a sharp rise in demand over the next few years. There are a number of new projects out there, and the task for us is to ensure we grow our capacity at a rate that’s aligned to demand. There aren’t very many companies in the marketplace that are doing what we do, so casting facilities are becoming increasingly capacity-constrained. Ceramics has the prospect of a very healthy and stable future, and we need to step up our capacity while remaining competitive.”

The core-making process will be made more efficient to cope with the demand, but it seems unlikely to undergo a sudden basic change in nature. “Nobody can tell what technological changes we’ll see in 10 years’ time,” Cox concluded, “but materials represent the obvious immediate area for developments. Our ability to keep ahead of the competition will depend on how smart we are in developing the high-temperature materials that customers require.”

That, of course, is an activity where Ross Ceramics has made smartness a habit.