Innovative domestic lighting has entered commercial production using plastic laser-sintering machines. Martina Methner reports.
One of the leading methods so far for rapid prototyping has matured to a technology for batch-sized, optimised production – including end products and spare parts. The technology creates parts directly from CAD data, without the need for moulds.
Based on CAD models of lights made by Materialise, Leuven, Belgium, can be customised to suit individual requirements. Individualisation is made possible by simply mutating the electronic data on-screen. A model is then frozen for downloading to Materialise’s plastic laser-sintering machines. The latter is capable of producing parts up to 700x380x580mm – over one metre across the diagonal. The lights are created by British designer, Lionel Theodore Dean, the proprietor of FutureFactories.
Said Mr Dean: “This is the first step towards widespread individualised customisation of products. It is revolutionising the way that interior decorators and designers assemble their collections and create limited editions to satisfy their clients’ wishes. The ultimate goal is to unleash a new era of mass-customised designs in which we are able to meet and exceed the customer's wildest dreams.”
Mr Dean is currently extending his use of plastic laser-sintering to furniture projects. The level of complexity that he is able to design into all his products could not be made a physical reality using conventional manufacturing techniques such as moulding and machining.
FutureFactories’ lighting products already in commercial production are ‘creepers’ and ‘RGB’. The more recent Tuber9 design will follow. Meanwhile, it has been accepted for the permanent design collection in The Museum of Modern Art (MoMA) in New York.
The example from FutureFactories is just one application showing that laser-sintering is not only suited for building prototypes or tooling. On the contrary, the technology is more and more embraced as manufacturing method: “Laser-sintering solutions perfectly meet current market requirements such as product individualisation, shortened product life cycles or one-off production,” said Hans Langer, CEO and founder of EOS, the manufacturer of laser-sintering systems.
The advantages of the technology have also been recognised by the automotive industry. Jaguar Cars is one of the companies that makes increasing use of laser-sintering. The manufacturer of luxury cars thus speeds up the development of new vehicles at its Whitley Engineering Centre.
The resulting components, such as the air intake manifold, door inners, fascia substrate, interior air vents and exterior light housings, are robust enough to be used on test vehicles running around the track. They allow for more data to be collected early on in the development process. Errors can therefore be avoided before they cause high costs.
The systems currently operate 24/7 at the Product Development Centre. Jaguar’s experience has been that the throughput of laser-sintered parts exceeds that of other rapid technologies. The entire build volume of a laser-sintering machine can be filled with parts. Other processes only allow for the fitting of components within the area of the build platform. The machines make it easy to incorporate dozens of parts in each sintering cycle.
An interesting component that is regularly added around other parts is not a prototype at all, but a complex plastic assembly aid. It assists operators working on the recently revealed XK coupé and convertible to position the window lift mechanisms during build. The manufacturing plant required a stock of 3000 of these parts. Once fitted, the assembly aid remains on the vehicle throughout the build process. By August 2005, around half of the parts required had been produced as fill-in jobs, without the need to invest in expensive plastic injection mould tooling.
As to the future, Jaguar expects to see rapid prototyping quickly develop into rapid manufacturing processes, initially capable of satisfying niche requirements. In
the more distant future it is possible that today’s processes hold the key to the next generation of volume production technologies. Especially laser-sintering has a high potential: the technology helps companies such as Jaguar to eliminate design constraints, tooling and inventory overheads.
What plays a vital role when it comes to the manufacture of end products are the materials. Over the years both the plastic and metal materials have been significantly improved so that, for example, parts built in today’s PA2200 polyamide material have mechanical properties comparable to and in some cases better than injection moulded PA12 or ABS. Glass-, aluminium- and carbonfibre filled versions are available which offer significantly higher stiffness and better thermal properties. Further fillers are being investigated to extend the range of properties. Some applications require very specific properties or certification, for example many medical and aerospace applications. Some laser-sintering plastics have already been certified as bio-compatible for long-term skin contact, and also a flame-retardant polyamide has been developed.
Metal parts in the latest tool steel material can have a tensile strength of up to 1100MPa and a hardness of more than 40 RockwellC. At the same time the accuracy and surface finish of the parts has been greatly improved. For example, the introduction in 1999 of fine metal powders for building parts with Direct Metal Laser-Sintering (DMLS) in 20micron layer thickness represented a real breakthrough for this application. Additional metal materials are being developed particularly with a view to direct manufacture of end-use parts, including cobalt chrome alloys, stainless steel and titanium alloys.
Martina Methner is with EOS GmbH – Electro Optical Systems – Krailling, Munich, Germany. www.eos.info
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