Rapid Prototyping SLS SLA Parts
SLA (Stereo Lithography Apparatus, The photosensitive resin is selectively cured).
The liquid tank is filled with liquid photosensitive resin, which is rapidly solidified under the irradiation of the ultraviolet laser beam emitted by the laser (SLA is different from the laser used for SLS, SLA uses ultraviolet laser, and SLS uses infrared laser). At the beginning of the forming, the lifting table is below the liquid level, just one layer thick. The cross-sectional profile is scanned along the liquid surface according to the machine command by the laser beam focused by the lens. The resin in the scanning area is rapidly solidified to complete a one-layer process to obtain a layer of plastic sheet. Then, the workbench is lowered by a layer thickness of the section layer, and the other layer section is cured. Such layer stacking constitutes a constructed three-dimensional entity.
Advantages of SLA technology:
1) the longest development time, the most mature technology and the most widely used. Among the rapid prototyping machines installed worldwide, photocuring systems account for about 60%.
2) The forming speed is faster and the system works stably.
3) Highly flexible.
4) High precision, can achieve micron level, such as 0.025mm.
5) The surface quality is good and smooth: suitable for fine parts.
Disadvantages of SLA technology:
1) Need to design support structure. The support structure needs to be removed when not fully cured, and the molded part is easily broken.
2) The equipment is expensive and the cost of use and maintenance is not low. SLA systems require precision equipment that operates on liquids and is demanding in the work environment.
3) Photosensitive resin is slightly toxic, pollutes the environment, and has an allergic reaction to some human skin.
4) Resin materials are expensive, but the strength, rigidity and heat resistance after molding are limited, which is not conducive to long-term preservation.
5) Since the material is a resin, the temperature will be too high to melt and the working temperature should not exceed 100 °C. It is brittle after curing, easy to break, and has poor processability. The molded parts are easy to absorb moisture and have poor corrosion resistance.