RP (Rapid Prototyping) technology was born in the late 1980s, and the rapid prototyping (prototype) technology developed in the 1990s is recognized as a major breakthrough in the field of manufacturing technology in recent years. Its impact on manufacturing can be related to numerical control technology. The appearance is quite beautiful. RP system integrates mechanical engineering, CAD, numerical control technology, laser technology and material science technology. It can automatically, directly, quickly and accurately transform design ideas into prototypes with certain structure and function or directly manufacture parts, so that product design can be made. Rapid evaluation, modification and functional testing have effectively shortened the product development cycle, and can quickly respond to market demands and improve the competitiveness of enterprises.

The rapid prototyping technology completely eliminates the traditional “removal” machining method (partially removing the material on the blank larger than the workpiece to obtain the workpiece), and adopts a new “growth” stacking method (using a layer of small blanks to gradually stack into large workpieces). , the complex 3D machining is decomposed into a simple two-dimensional machining combination), therefore, it does not have to use traditional machining machines and tooling, only 10% to 30% of the working time and 20% to 35% of the traditional processing method At a cost, product samples or molds can be produced directly. Rapid prototyping has the above-mentioned outstanding advantages, so it has developed rapidly in recent years. It has become a pillar technology in modern advanced manufacturing technology and an indispensable means to realize Concurrent Engineering.

First, the background generated by RP&M technology

With the formation of global market integration, the competition in the manufacturing industry is fierce, and the speed of product development has increasingly become the main contradiction of market competition. In this case, the ability (cost and cycle) of autonomous rapid product development (rapid design and rapid tooling manufacturing) becomes the strength of the global competitiveness of the manufacturing industry. At the same time, in order to meet the increasingly individualized market demand, the manufacturing industry also requires strong flexibility in manufacturing technology, and can organize production in small batches or even in a single piece without increasing the cost of the product. Therefore, the speed of product development and the flexibility of manufacturing technology become critical.

For half a century, the development and popularization of technologies such as computers, CAD/CAM, NC, materials and lasers have also laid the foundation for the emergence of new manufacturing technologies on a technical level.

It is in this social context that RP&M-Rapid Prototyping/Parts Manufacturing was produced in the United States in the late 1980s and rapidly expanded to Europe and Japan, which is considered to be the field of manufacturing technology in recent years. A major breakthrough.

Second, the principle and main methods of RP&M

RP&M technology refers to the general technical name for the rapid manufacture of three-dimensional entities of arbitrary complex shapes by the CAD model of parts under computer control and management. It is the integration of many modern advanced technologies. Rapid prototyping technology uses the discrete/stacking forming principle to obtain the stacked paths and ways by discretely, and “stack” the materials by precise stacking to form complex three-dimensional entities. The analogy of the rapid prototyping system to the "3DSolid Printer" is very vivid.

The discrete/stacking process begins with a three-dimensional CAD model: first discretizes the CAD model, and cuts a certain direction (often taking the Z direction) into many layers, ie, layering, which is an information processing process; The layers are stacked in sequence, and the layers are combined to form a three-dimensional solid part, which is the physical embodiment of the CAD model. Each RP device and its operating principle are based on a layer-by-layer overlay process.

There are more than 30 specific processes for RP&M technology, most of which were developed by the United States. Here are the five most mature ways.

1. Three-dimensional printing (SLA, Stereolithgraphy Apparatus) forming technology

The basic working principle: the surface of the photosensitive resin is scanned by ultraviolet laser, so that it can be solidified regularly, from point to line, then to the surface, to complete the construction of one layer, each time generating a layer of the part. During the scanning process, only when the exposure amount of the laser exceeds the threshold energy required for the curing of the resin, the liquid resin undergoes polymerization to form a solid state. Therefore, during the scanning process, the scanning speed is automatically adjusted for different amounts of curing depth to match the amount of exposure produced and the amount of exposure required to cure a certain depth. After each layer has been cured, the lifting table is moved a distance of one ply thickness, and then the resin is applied to the previous layer to build a layer. So repeatedly, each new layer is adhered to the previous layer until the last layer of the part is made, becoming a three-dimensional entity. After the parts are stacked, some necessary post-processing is performed on the parts, and the entire manufacturing process is completed.

Next page

Construction & Decoration

Geosynthetics Products,Prefabricated Building,Other Prefabricated Building

Fiberglass Geogrid,PVC GeomembraneCo., Ltd. , http://www.chgeotextile.com