Photocuring 3D printers: technical principles and selection of SLA, DLP and LCD

In recent years, 3D printing has become very popular. According to the printing principle and printing materials, 3D printers can be divided into different types. As the manufacturer of photocuring resins, Bossin will discuss the 3D printers which use photocuring resins today. There are three common photocuring 3D printers: SLA, DLP and LCD. Let's talk about the principles and technical comparisons of these three photocuring 3D printers.

SLA is short for stereolithography technology. It is the earliest commercialized 3D printing technology. The basic principle of SLA molding is to use laser as the light source, and the laser beam focused by the lens scans the cross-section contour along the liquid surface according to the device instructions. The photosensitive resin in the scanned area is quickly solidified. Then the workbench is lowered by the thickness of one layer of cross section, and then another layer of cross section is solidified. In this way, the layers are stacked to form a three-dimensional entity.

DLP is digital light processing rapid prototyping technology. The basic principle of its prototyping is that the printed model will be cut into layers horizontally by the 3D printing software, and the projector will project the model shape of the first layer into the resin tank for photocuring. After the first layer is formed, the workbench will slightly raise, and project the next model shape into the resin tank for the next layer. The model is printed out in such repeated stacking manner. Different from the single-point exposure of SLA, DLP uses surface exposure, which can greatly increase the printing speed. At the same time, DLP is generally superior to SLA 3D printers in terms of accuracy and surface quality.

LCD is liquid crystal display technology, which is similar to DLP printing technology, but it does not use a projector to produce images. It uses the imaging principle of LCD screens to create selective transparent areas on the LCD screen. Ultraviolet light passes through the transparent areas, and irradiates the photosensitive resin in the resin tank for exposure and curing. After the curing time of each layer is over, the platform tray lifts the cured part, to allow the photosensitive resin to replenish and reflux. Then the platform drops again, and the thin layer between the model and the release film is exposed to ultraviolet light again, thereby curing and rising layer by layer to print into a beautiful three-dimensional model.

The three types of photocuring 3D printers have their own characteristics. So how do you choose the printer that suits you? If you need to print large-scale models and mass production, SLA is the best choice.  If you pursue molding speed and printing accuracy, DLP is a good choice. If you focus on cost-effectiveness, LCD is a good choice.

As a manufacturer of photocurable resins, Bossin can customize suitable photocurable resins for 3D printing according to customer requirements. You are welcome to consult us for sample testing.