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Several new RP processes using powder materials are either under development or about to be commercialized. Unlike selective laser sintering (SLS), which also uses powders and has been available for many years, these new technologies quickly fuse entire layers of parts in a single operation. SLS, by contrast, uses a laser which is guided over the surface of each layer in vectorial-fashion to fuse the powder; a process which take much longer. The inside of the machine with the exposure mask at the left (white), and the fused top layer of a group of parts being fabricated. Speed Part AB (Sweden) is expecting to commercialize their technology in 2003. It only takes about 10 seconds to fuse each 0.004 inch (0.1mm) layer of a part using their method, and this time is not dependent on part geometry. Several materials are being developed for use with the system, the first being nylon. The first machine has a build envelope of 8x12x20 in (200 x 300 x 500 mm).     The photo at the left shows an electrical box part emerging from the powder. On the right is an unreduced close-up from the original photo. All photos courtesy of Speed Part AB.   The machine utilizes components similar to both SLS, and one of the earliest commercial RP methods, solid ground curing (SGC). Building material powders are handled in much the same way as in SLS. However, each layer is imaged in a process much like SGC. Each slice is electrostatically printed as a negative image using toner deposited on a glass plate. The imaging method is similar to that used in photocopiers. The toner image on the glass plate is then used as an exposure mask for the layer. The schematic in (A) shows the glass plate carrying the toner image being moved into position above the build cylinder, which has been coated with a layer of part-building powder. The powder spreading mechanism is represented in B. Once the glass plate gets into position (C), an infrared radiation source is activated to expose the entire layer at once (D & E). The glass plate is then stripped of the toner and made ready to print the next layer (F). Machine operation: (A) Creating the mask; (B) spreading build powder; (C) ready for exposure. Machine operation: (D, E) IR exposure; (F) cleaning toner off the mask.   Speed Part says the technology is about four times as fast as competing laser-based powder systems, and would be about one third the cost at its expected selling price of $100,000. The company is aiming at tool-less-production applications where its speed offers a strong advantage. At 10 seconds per layer, the machine should be able build at a rate considerably over an inch of Z-height per hour. Since many smaller parts can be built at once, the approach may be very rapid and economical for producing small volumes of parts. For more info Contact: Speed Part AB Radanas SE-435 33 Molnlycke Sweden +46 (0)31 338 3990 Ralf Larson, CEO ralf.larson@speedpart.se