3D printing technology is widely used in various fields overseas, helping to improve development efficiency and reduce production costs, and 3D printers are also becoming widespread.
It is still widely used in China for late start. The main reasons are:
- 1.There is still a long way to go before the market grows. Currently, most manufacturing companies in China do not accept advanced manufacturing concepts such as “digital design” and “small lot production”. The lack of understanding of the strategic implications of this emerging technology (3D printing) does not understand what this emerging technology can do and how much value it creates.
- 2. Enterprise-level professional-grade 3D printers and their materials are also relatively expensive and have low customer acceptance. Thousands of low-cost 3D printers already exist on the market, but this entry-level 3D printer is suitable for individuals and enthusiasts to buy. It is difficult to use in specialized fields such as aerospace and medicine, as well as in industrial manufacturing, construction engineering and other fields. Prices for professional-grade 3D printing equipment typically range from hundreds of thousands to millions, disappointing many companies involved in 3D printing technology.
- 3. Various materials are not enough, limiting the promotion of 3D printing technology. There are many plastic materials, from hot melt to high temperature, transparent to opaque, biocompatible to castable, but from elastic to hard. There are many different materials, but they are still not as good as traditional materials.
- 4. 3D digital technology is not yet widespread and the market size of 3D printers is limited. Since the premise of 3D printing is that there is 3D data printed on a computer, the acquisition and creation of 3D data is still a common public technical activity. China’s most powerful digital professional field is Hangzhou Xianlin 3D Technology Co., Ltd., which independently develops various 3D scanners in various application fields. This helps to quickly capture 3D data of objects, and STL digital models can be used for 3D printing, which has lower CAD modeling technology requirements.
Currently, there are many different 3D printer molding technologies on the market. 3D printers of different technology types include SLS, DMLS, FDM, SLA, DLP, FFF, MEM, LOM, EBM, SHS, 3DP. Among them, SLS, FDM, SLA, LOM and 3DP are more mature.
3D printing technology methods and classification
Liquid resin solids: SLA, BIS, LTP, HIS, SGC
Fused Deposition Modeling: FDM, BMP, 3DW, SDM, ES
Laser welding material SLS, GPD
Adhesive 3DP, SF, TSF
Adhesive sheet material LOM
UV adhesive sheet material SFP
SLA (Stereolithography Appearance)
On the surface of the photocurable material (liquid photosensitive resin material), lasers having a specific wavelength and intensity are solidified one-to-one in a point-by-point manner to complete the stretching operation of one layer. The elevator is then moved one level vertically to cure the other layers. The layers are stacked to form a three-dimensional entity.
FDM (Fused Deposition Modeling)
This method uses filamentous materials (paraffin, metal, plastic, low melting point alloy wire) as raw materials. An electric heating method that heats the silk material to a temperature slightly above the melting point (about 1 ° C above the melting point), under computer control, the spray head moves in a plane and the molten material is applied to the workbench. .. After cooling, a layer of cross section of the workpiece is formed. After forming the layers, the nozzle is moved to a certain level and a layer of coating is applied to form a three-dimensional workpiece layer for each layer.
SLS (Selective Laser Sintering)
The entire process unit consists of a powder cylinder and a forming cylinder. During operation, the powder cylinder piston (powder supply piston) rises, and the powder spreads uniformly on the piston (operating piston) of the forming cylinder by the powder diffusion roller. The computer controls the two-dimensional scanning trajectory of the laser beam according to the prototype slice model and selectively sinters the solid powder material to form layers of parts. After the powder completes one layer, the working piston is lowered into a thick layer and the powder application system covers the new powder. Control the laser beam to scan the new layer again. This loop stacks layers up to the shape of the 3D part. Finally, the unbaked powder was collected in a powder can, and the molded product was taken out. In metal powder laser sintering, the entire table is heated to a constant temperature before sintering to reduce thermal deformation during molding and promote adhesion between layers.
3DP (3D printing)
The 3DP process is similar to the SLS process and is formed using powder materials such as ceramic powder, metal powder and the like. By heading with an adhesive (eg, silica gel) of a “printed” cross-section member on top of the raw material powder, except that the powder material is not connected by sintering. Adhesive-bonded parts have low strength and require post-treatment. The specific process is as follows: After bonding the upper layer, the forming cylinder is lowered by a distance (layer thickness: 0.013 to 0.1 mm), the cylindrical powder raises the introduction of the number of powders by a certain height, and the spreader roller is cylindrical. It is pushed to the molding powder. It is flat and compact. The spray head is under computer control and pushes the molded portion of the molded data to selectively inject the adhesive building layer. When the powder rolls are dispersed, the powder recovery device collects excess powder. In this way, the powder is supplied and sprayed onto the adhesive, and finally the adhesion of the three-dimensional powder is completed. Where the adhesive is not sprayed is a dry powder that acts as a support during the molding process and is relatively easy to remove after molding.
LOM (laminated manufacturing)
LOM is a layered solid manufacturing process, also known as a stacking process, that uses sheets (paper, plastic film, composites, etc.) as raw materials. The laser cutting system uses computer-extracted cross-section profile data to cut the inner and outer contours of the workpiece with a laser using paper coated with a hot melt adhesive on the back. After cutting the layers, the feed mechanism stacks new layers of paper, joins the cut layers together using a thermocompression bonding device, cuts and finally cuts, cuts and cuts into a three-dimensional work piece. Let me.
Link to this article：Factory that provides a technical description of 3D printed parts
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