60 second interview: Lesley Selsdon

How did you get into engineering? We originally had a family plastics business many years ago making fountain pens and ballpoint pens – and that's how I got involved. I went to Switzerland to learn toolmaking on automatic screwcutting machines to make ballpoint tips. How did you get started in the field of oil filtration? We sold the plastics business and someone came to me about an oil filtration system using what was essentially a toilet roll in a housing and originally backed by Sir Monty Finniston, the chairman of British Steel. I had a look at it and thought 'this is interesting'. I thought the way they were doing it didn't look very elegant, being a great big pot with pipes coming out of it. I had the idea of making it like a silencer on a gun – getting a conventional oil filter and making a bypass housing between that and the engine so that you combine the best of both worlds. I finally got a patent on that idea and it worked and was very successful. The Royal Mail and Avis used it. Then I sold that original technology 15 years ago and, in the meantime, technology moves on – and the media moves on considerably. Now, I'm using a completely new medium as cellulose, which was the original one, is very good, but only holds two or three times its own weight in water and is very dense and heavy, so requires a huge pump to push the oil through it. New super-absorbent filter media had come along, which could hold 15-30 times their own weight in water and is 90% air, so the end result is that you have pulled out loads of water, don't need a huge pump and you don't have pressure drops. It combines purification – removal of water in this case – with filtration down to 50 ppm in the same housing and we don't have the expense involved in installing it. It's the difference between a valve and a transistor – it's a quantum leap that changes the game. How have you taken the technology forward? What started the latest application for me was my involvement with JCB. I was really concerned with oil filtration for automotive. However, they weren't because they were buying spin-on oil filters as a commodity. What they were concerned with was water in hydraulic oil. I felt I had the answer and they backed me and bought some of the original 'Oil Genie' products in a case and they were very pleased. I went back to the drawing board and I wasn't satisfied with the original design because it had a peristaltic pump. That was fine, but it rocketed in price and had design problems in terms of the flow rates. So I went back to the drawing board and got this proof of concept award and, through funding from the EU, Warwick University and Coventry University, I've been able to buy the latest testing equipment, including the latest Karl Fischer machine and the latest particle counting machine. We've redesigned the whole thing so that it's simpler and better than it's ever been before. There's also a big environmental aspect to the filtration process. because of the need to filter out mutagens from lubricating oils. I realised early on that used lubricating oil is very dangerous because of the number of mutagens produced in petrol and LPG engines. However, that wasn't the case for diesel engines.?The reason was that the soot produced by incomplete combustion in a petrol engine was pulling the mutagens out and effectively acting as a filter. How do you plan to market the product? I hope by the end of the year to be able to invite those who are interested in the idea to a presentation at Warwick University.The business model has three scenarios after that. We could offer the service and not sell the product, or we could offer the unit plus the replaceable elements or we could offer it as a one-off, disposable unit. I'm not yet sure which way we're going to go with it. What has kept you interested in this technology? The intellectual challenge is a big part of it. Once you're an inventor, you're an inventor – it's in the blood. It's a tortuous route, though. It's not a straight line.