Classification of CNC Rapid Prototyping Technology
CNC rapid prototyping is an innovative technology that allows you to produce complex parts directly in a few hours using 3D CAD design graphics. (LOM), powder sintering CNC rapid prototyping (SLS), melt deposition method CNC rapid prototyping (FDM) and 3D printing technology. Since the first CNC rapid prototyping system in 1988, more than twenty systems have been developed, and each system has some small differences. Initially, these systems were used in the automotive and aerospace sectors and were used in many other areas, such as toys, computers, jewelery and medicine.
Stereo light curing (SLA): SLA method is the earliest commodity, the market share of the highest RP technology, it is photosensitive resin as raw material, computer-controlled UV laser by the parts of the layered cross-section information in the photosensitive resin surface point by point scan, So that the resin layer of the scanned area is photopolymerized and solidified to form a thin layer of the part. After a layer of curing, the table down a layer of thick distance, so that the original solidified resin surface and then apply a layer of new liquid resin, and then the next layer of the scanning process. The newly cured layer is firmly adhered to the previous layer, so repeatedly until the entire prototype is finished.
Fused deposition method (FDM): FDM method was invented in 1988. Sprinkler in the nozzle of the molten material in the X-Y table driven, according to the cross-sectional shape of the shop in the floor, a layer of processing, and ultimately manufacture parts. Commercial FDM equipment uses a wide range of materials, such as casting paraffin, nylon, thermoplastics, ABS and so on. In addition, to improve efficiency can use multiple nozzles.
Laser Sintering (SLS): SLS method uses infrared laser for energy, the use of modeling materials are mostly powder material. CNC Rapid Prototyping In the process of processing, the powder is preheated to a temperature slightly below its melting point and then the powder is paved by the action of a flattened stick. The laser beam is selectively sintered under the control of the layered section according to the layered section information. And then the next layer of sintering, all sintering finished after removing the excess powder, you can get a sintered parts. At present the mature process materials for the wax powder and plastic powder, with metal powder or ceramic powder sintering process is still under study.
LOM: LOM appears in 1985. First, the substrate is covered with a layer of foil (such as paper), and then use a certain power of the infrared laser in the computer under the control of the layered information cut out the contours, while the non-part of the grid part of the grid cut into pieces Remove, after processing a layer, and then covered with a layer of foil, with a hot roller rolling, so that the new layer of a layer of adhesive in the role of adhesive has been molded in the body, and then cut the shape of the layer, So repeatedly until finished processing. Finally, remove the excess part of the chopped, you can get a complete part.
3D printing technology: 3D printing technology and laser molding technology (SLA), the use of hierarchical processing, superposition forming, that is, by layer to increase the material to generate 3D entities, CNC Rapid Prototyping each layer of the printing process is divided into two steps, first In the need to form a layer of special glue spray, glue droplets itself is very small, and difficult to spread. And then spray a layer of uniform powder, the powder encountered glue will quickly curing the bond, and no glue area remains loose. So that in a layer of glue a layer of powder alternately, the solid model will be "printed" shape, after printing as long as the removal of loose powder can "plan" out of the model, and the remaining powder can be recycled.