Today, 3D printing, rapid prototyping, rapid manufacturing, digital manufacturing of these terms, as a whirlwind, as if overnight in academia, politics, media, financial, manufacturing industry set off a giant Lan. However, there is not yet a whole article to be able to fully and completely analyze these terms, so that people really want to understand “what is 3D printing”, “what is rapid manufacturing.” Rapid Prototyping (RP), born in the late 1980s, is a new technology based on material stacking and is considered to be a significant achievement in the past 20 years. It integrates mechanical engineering, CAD, reverse engineering technology, tiered manufacturing technology, CNC technology, material science, laser technology in one, can automatically, directly, quickly and accurately change the design idea into a certain function of the prototype model or direct manufacturing product, Thus for the parts prototype production, the design of the new design and other aspects of the provision of a highly efficient and low-cost means of implementation.
Rapid Manufacturing (RM), in a narrow and broad sense, is a new manufacturing concept based on laser powder sintering rapid prototyping technology. It is actually one of the branches of RP rapid prototyping technology, Directly and automatically to the rapid, flexible and have a lower cost of manufacturing prototype. Rapid manufacturing It is compared with the general rapid prototyping technology, is able to directly produce the final product, can be adapted from a single product manufacturing to the bulk of the personalized product manufacturing; and broadly, RM rapid manufacturing can include “fast mold” technology and CNC machining technology, etc., it can be with the RP rapid prototyping technology rivalry, the best wins field. Internationally like to use “Additive Manufacturing” (referred to as AM) to include RP and RM technology, domestic translation for the incremental manufacturing, timber manufacturing or add manufacturing.
SLA rapid prototyping: (SLA – Stereolithography)
The technology uses the photosensitive resin as the raw material, the computer under the control of the UV laser according to the contours of the predetermined parts of the profile of the profile of the liquid resin on the point of scanning, the resin will be scanned by the thin layer of photopolymerization reaction to form parts A thin section. When the layer is cured, move the table, in the original solidified resin surface and then apply a new layer of liquid resin for the next layer of scanning and curing. The newly cured layer is firmly bonded to the previous layer and is repeated until the entire part prototype is finished. US 3DSYSTEMS company is the first company to introduce this technology. The technical characteristics are high precision and finish, but the material is relatively brittle, the operating cost is too high, the post-processing is complex, the operator requirements are higher. Suitable for verification assembly design process.
3D printing: (3DP – 3Dimension Printer)
Its biggest feature is the miniaturization and easy operation, and more for commercial, office, research and personal studio and other environments. According to the different printing methods, 3D printing technology can be divided into hot-burst three-dimensional printing and piezoelectric three-dimensional printing. The principle of the thermal explosion-type three-dimensional printing process is to send the powder from the storage barrel to send a certain weight, and then the drum will be sent out of the powder in the processing platform covered with a thin layer of raw materials, print head in accordance with the 3D computer model sliced after the two-dimensional The layer information ejects the standing agent and sticks the powder. After finishing a layer, the processing platform automatically drops a little, the storage bucket rises a little, the scraper pushed the powder from the raised storage bucket to the working platform and flattened the powder so that the desired shape can be obtained. The technology is characterized by fast speed (6 times that of other processes) and low cost (1/6 of other processes). The disadvantage is that the accuracy and surface finish are low.
SLS – Selected Laser Sintering (SLS – Selected Laser Sintering)
The method uses C02 laser for energy, the current use of modeling materials for a variety of powder materials. (100μ-200μ) powder is uniformly spread on the workbench, and the laser beam is selectively sintered according to the layered profile of the material under the control of the computer. After the completion of the layer, the next layer is sintered. After all the sintering to remove the excess powder, and then grinding, drying and other treatment will get parts. At present, the process materials for the nylon powder and plastic powder, as well as the use of metal powder sintering. SLS equipment can be used to manufacture the profiled hot runner system of metal mold and injection mold directly. Hardness up to higher Rockwell hardness, performance to the level of forgings, you can directly create special, complex functional parts. It is due to the small batch of SLS technology special, complex function of the rapid manufacturing capacity, and can be a number of parts one-time molding manufacturing, to achieve multi-species, personalized small batch rapid manufacturing, so that the technology in aerospace, Automotive engine testing and development, medical field has been widely recognized and applied.
Vacuum Casting Mold (VCM – Selected Laser Sintering)
Also known as “vacuum injection mold”, that is, the use of the original model, in a vacuum state to produce a silicone mold, and in a vacuum state using PU material for casting, and thus cloned with the original template the same copy, The most commonly used fast mold technology, through this technology, can produce a variety of functional characteristics to meet the similar engineering plastics products, while the small batch production.General a set of VCM silicone mold can copy around 20 sets of products, especially for small and medium-sized, fine pieces of the copy, such as instrumentation, auto parts manufacturing industry. This process can meet the needs of the product in the trial process, the time is short, low cost, fast. This is very important prototype manufacturing process.
CNC machining (Computer Numerical Control, CNC)
CNC is a program controlled automation machine. The control system can logically process the program with the control code or other symbol instruction, decode it by the computer, so that the machine can carry out the prescribed action, and the blank material is processed into semi-finished finished parts by cutting tool. CNC machine tools in the manufacturing industry, especially in the automotive, aerospace, and military industry is widely used, both in terms of hardware and software , Have a rapid development. CNC compared to traditional machine tools, it has a digital, efficient, batch characteristics, in addition to the complex shape of the workpiece, the basic can cope, so although not strictly in the sense of rapid prototyping technology, but the industry is usually put it into the fast Manufacturing category.