1、中英文资料（一） RP&M 1. What is RP&MManufacturing community is facing two important challenging tasks:(1)substantial reduction of product development time; and （2） improvement on flexibility for manufacturing small batch size products and a variety of types of products. Computer-aided design and manufactur
2、ing（CAD and CAM） have significantly improved the traditional production design and manufacturing. However, there are a number of obstacles in true integration of computer-aided design with computer-aided manufacturing for rapid development of new products. Although substantial research has been done
3、 in the past for computer-aided design and manufacturing integration, such as feature recognition, CNC programming and process planning, the gap between CAD and CAM remains unfilled in the following aspects:rapid creation of 3-D models and prototypes.cost-effective production of patterns and moulds
4、with complex surfaces.To substantially shorten the time for developing patterns, moulds, and prototypes, some manufacturing enterprises have started to use rapid prototyping（RP）methods for complex patterns making and component prototyping. Over the past few years, a variety of new rapid manufacturin
5、g technologies, generally called Rapid Prototyping and Manufacturing（RP&M）, have emerged; the technologies developed include Stereolithography（SL）, Selective Laser Sintering（SLS）, Fused Deposition Modeling（FDM）, Laminated Object Manufacturing（LOM）, and Three Dimensional Printing（3-D Printing）. These
6、 technologies are capable of directly generating physical objects from CAD databases. They have a common important feature: the prototype part is produced by adding materials rather than removing materials, that is, a part is first modeled by a geometric modeler such as a solid modeler and then is m
7、athematically sectioned（sliced）into a series of parallel cross-section pieces. For each piece, the curing or binding paths are generated. These curing or binding paths are directly used to instruct the machine for producing the part by solidifying or binding a line of material. After a layer is buil
8、t, a new layer is built on the previous one in the same way. Thus , the model is built layer by layer from the bottom to top. In summary, the rapid prototyping activities consist of two parts: data preparation and model production.2.The history of RP&M As usual with invention, one individuals impati
9、ence was the prototyping industry, now barely a decade old. Its father, Charles W Hull, 58 , still works as vice chairman and chief technology officer at the RP company he helped found in 1986, 3D Systems of Valencia, Calif. As an engineer, Hull had always been bothered by the long time it took to m
10、ake prototype models of plastic. They had to be machined by hand, he recalls. If more than one was needed, generally the case in industry, molds for making plastic prototypes had to be individually machined.The building blocks of a better system were lying around. Hull had been working for a small c
11、ompany that used ultraviolet lamps to substitute a laser for an ultraviolet lamp. “But taking that insight to a practical machine came slowly,” Hull recalls, and required several years of Edison-style inspiration. （In fact, a prototyping machine based on conventional UV light was developed in 1998 b
12、y The Institute of Advanced Manufacturing Technology, Xian Jiaotong University, China）.The results was the first prototyping machine, introduced by 3-D Systems in 1987. It could fabricate small, transparent plastic parts from CAD drawings in hours or at most days. The machine builds the model in lay
13、ers, from the bottom up. A laser, which causes molecules of a photosensitive liquid resin to polymerize, scans above a vessel filled with the resin. The laser first traces the outline of a layer on the resins surface. Next, like an artist shading a panel in a pencil drawing, the beam crisscrosses th
14、e whole outlined area to harden it. Then the platform holding the model sinks so the layer is barely awash in liquid resin, the laser goes to work solidifying another layer atop it, and so on. When the translucent object is done, it is raised from the vat, dripping like a mermaid just emerged from t
15、he sea.Hull dubbed the process stereolithography, and it still dominates RP. The resins were, and still are very expensive: A gallon of acrylic blends of photo-curable liquids fetches about $750. But so great is industrys hunger for prototypes, in an era when the pool of high-paid artisans who can m
16、ake them by hand is shrinking and time to market is king, that designers were glad to get the first RP machines at any price. 3-D Systems has grown to an $80-million-a-year public company thats still No.1 in the field by far.Before long other inventors jumped in. Michael Feygin, an immigrant Russian engineer, hit on the idea of building prototypes from inexpensive slices of paper. His company, Helisys of Torrance, Calif., makes remarkably sturdy o
