The forming principle of SLA3D printing technology: filled with liquid photosensitive resin, the ultraviolet laser beam emitted by the helium cadmium laser or argon ion laser under the control of the control system scans the photosensitive resin surface point by point according to the information of each layered section of the part, so that the resin thin layer in the scanned area will produce photopolymerization reaction and solidify, forming a thin layer of the part. After the curing of the first layer, the workbench shall move down a distance of layer thickness so that a new layer of liquid resin can be applied on the surface of the previously cured resin. The scraper shall scrape the liquid level of the resin with high viscosity, and then the scanning processing of the next layer shall be carried out. The newly cured layer shall be firmly bonded to the previous layer. Repeat this until the whole part is manufactured to obtain a three-dimensional solid prototype. Process of SLA3d printing technology: The production of UV curing rapid prototyping can generally be divided into three stages: pre-processing, prototyping and post-processing.

    In the pre-processing stage, the 3D solid model is designed through CAD, and the prototype is transformed, positioned, supported, sliced with discrete programs, and the scanning path is designed. The generated data will accurately control the movement of the laser scanner and the lift table, which is actually the data preparation for the prototype production; Prototyping is to perform UV curing molding on a dedicated UV curing rapid prototyping equipment system. Before prototype production, it is necessary to start the photo curing rapid prototyping equipment system in advance to make the temperature of the resin material reach the preset reasonable temperature, and a certain stabilization time is required after the laser is ignited. After the equipment operates normally, start the prototype production control software, read the slice data file generated by pre-processing, and then start the stack production. The whole photocuring process of the lamination is automatically completed under the control of the software system, and the system automatically stops after all laminations are made. Post processing: After the prototype stack is made in the rapid prototyping system, it is necessary to carry out subsequent processing such as stripping to remove waste materials and support structures.

    Advantages and disadvantages of SLA 3d printing process: advantages of SLA technology 1. UV curing is the earliest rapid prototyping manufacturing process with high maturity, which has been tested by time. 2. The prototype is directly made from CAD digital model, with fast processing speed, short production cycle, and no need for cutting tools and molds. 3. Prototypes and molds with complex structure and shape or difficult to form by traditional means can be processed. 4. Make the CAD digital model intuitive and reduce the cost of error repair. 5. Provide samples for experiments, and verify and check the results of computer simulation calculation. 6. It can be operated online and controlled remotely, which is conducive to the automation of production. Defects of SLA technology 1. The SLA system is expensive, and its use and maintenance costs are too high. 2. SLA system is a precision equipment for liquid operation, which requires strict working environment. 3. The molded parts are mostly resin, with limited strength, stiffness and heat resistance, which is not conducive to long-term storage. 4. The pre-processing software and the driver software have a large amount of calculation, and have a high correlation with the machining effect. 5. The software system is complex to operate and difficult to get started; The file format used is not familiar to most designers. SLA development trend and prospect SLA technology is mainly used to manufacture a variety of molds, models, etc; The SLA prototype can also be used to replace the wax pattern in investment casting by adding other ingredients into the raw materials. SLA technology has fast forming speed and high precision, but due to shrinkage during resin curing, it will inevitably produce stress or deformation. Therefore, developing photosensitive materials with small shrinkage, fast curing and high strength is its development trend. The development trend of stereolithography is high speed, energy saving, environmental protection and miniaturization. The continuously improved machining accuracy makes it possible to make great achievements in biology, medicine, microelectronics and other fields.