Digital Light Processing (DLP) came into being over a decade after the emergence of Stereolithography Apparatus (SLA) technology. As a variant of SLA, it bears remarkable similarities to SLA in terms of molding technology, achieving comparable effects through different approaches. This technology is also widely acknowledged in the industry as the second-generation stereolithography technology.

SLA technology mainly uses photosensitive resin as raw material and utilizes the characteristic that liquid photosensitive resin will be rapidly cured under ultraviolet irradiation. Photosensitive resin is generally liquid, and it will immediately cause a polymerization reaction under the irradiation of ultraviolet light with a certain wavelength to complete the curing. SLA focuses ultraviolet light with a specific wavelength and intensity on the surface of the photosensitive resin, so that it solidifies point-by-point and line-by-line, ultimately forming a complete cross-sectional layer. After completing the drawing operation of one layer, the lifting table moves a layer height in the vertical direction, and then another layer is cured. Layers are stacked to form a three-dimensional object, and the formation of the pattern of each layer is controlled by the movement of the laser beam. In theory, the laser beam can move in a large space. Therefore, SLA technology can print large-sized

Previously we mentioned that 3D printing can be divided into 7 categories, including material extrusion, binder jetting, powder bed fusion, material jetting, sheet lamination, directed energy deposition, and stereolithography. Below we will introduce these 7 categories in details.

In recent years, 3D printing technology has developed rapidly and has gradually become an indispensable part of modern manufacturing. According to the latest data from the "2024 3D Printing Trend Report" by Protolabs, the global 3D printing market size reached US$22.14 billion in 2023 and is expected to grow to US$57.1 billion by 2028.