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Technical introduction
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Ultraviolet laser rapid prototyping photo gallery
 
瑞丰恒激光
 
 
       Laser rapid prototyping is a prototype that uses discrete stratification and layer-by-layer stacking to directly use the 3D computer data of the product. The materials used in the rapid prototyping of ultraviolet lasers are mainly photosensitive resins. The surface is smooth and the quality is good; the molding precision is high, the precision is 0.1mm; the molding product with very fine details and thin-wall structure can be made with high precision and easy post-processing.
 
 
The process of rapid prototyping is as follows:
 
       1) Construction of a three-dimensional model of the product. Since the RP system is directly driven by the 3D CAD model, it is first necessary to construct a 3D CAD model of the workpiece being machined. The 3D CAD model can be directly constructed using computer-aided design software (such as Pro/E, I-DEAS, Solid Works, UG, etc.), or a 2D pattern of an existing product can be converted to form a 3D model, or a product entity. Laser scanning and CT tomography are performed to obtain point cloud data, and then a reverse engineering method is used to construct a three-dimensional model.
 
       2) SLA laser rapid prototyping
 
       The SLA process, also known as light modeling or stereolithography, works on the principle of photopolymerization of liquid photosensitive resins. The liquid material can rapidly undergo photopolymerization under ultraviolet light of a certain wavelength and intensity, and the molecular weight sharply increases, and the material changes from a liquid state to a solid state. The liquid tank is filled with liquid photocuring resin. Under the action of the deflection mirror, the laser beam can scan on the liquid surface. The scanning track and the presence or absence of light are controlled by the computer. When the light spot is hit, the liquid is solidified. At the beginning of the forming, the working platform is at a certain depth below the liquid level, and the focused spot is scanned point by point on the liquid surface according to the instruction of the computer, that is, solidification point by point. When a layer of scanning is completed, the unirradiated area is still a liquid resin. Then the lifting platform drives the platform down to a height, and the formed layer is covered with a layer of resin. The scraper scrapes the liquid surface of the resin with higher viscosity, and then scans the next layer, and the newly cured layer is firm. The ground is glued to the previous layer and repeated until the entire part is manufactured, resulting in a three-dimensional solid model.
 
       3) Post-processing of molded parts.
 
       The molded part is taken out from the molding system, polished, polished, coated, or placed in a high-temperature furnace for post-sintering, and further enhanced in strength.
 
 
Material properties
 
       SLA material
 
       The photosensitive resin is a substrate formed by laser curing rapid prototyping, and its performance characteristics have a decisive influence on the quality of the molded part. Photocuring resins using SL should generally have the following properties:
 
       1) low viscosity, low viscosity resin is conducive to faster leveling of resin during molding;
       2) The curing speed is fast, and the curing speed of the resin directly affects the molding efficiency, thereby affecting the economic benefits;
       3) The curing shrinkage is small, and the photosensitive resin undergoes a change from liquid to solid during the curing process. This change often causes linear and volume shrinkage of the resin, and the curing shrinkage causes deformation, warpage, cracking, etc. of the part. Affecting the precision of the molded parts and reducing the shrinkage of the resin is the main goal in the development of the photosensitive resin, and the low shrinkage resin is advantageous for molding the precision parts;
       4) A high degree of curing at a time, which can reduce post-cure shrinkage, thereby reducing post-cure deformation;
       5) The wet strength is high, and the high wet strength can ensure that the post-cure process does not cause deformation, expansion and interlayer peeling;
       6) The swelling is small, and the swelling of the wet molded part in the liquid resin sample piece in the liquid resin causes the part size to be large;
       7) Low toxicity, which is beneficial to the health of the operator and does not cause environmental pollution.
 
       The main application of SLA molded parts
 
       1) Directly make various resin sample pieces or functional parts for structural verification and functional testing;
       2) making fine parts;
       3) manufacturing parts with transparent effects;
       4) The prototype can be quickly turned into various molds, such as silicone rubber mold, metal cold spray mold, ceramic mold, electroforming mold, epoxy resin mold, lost mold, etc.
       5) Instead of the lost mold in investment casting, it is used to produce metal parts.