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Stereolithography vs. Digital Light Processing

by: May 14,2021 556 Views 0 Comments Posted in 3D Printing

3D printing Stereolithography Craftsmanship


What is Stereolithography?

Stereolithography is one of the techniques for producing 3D-printed materials. It is also called SLA. The mechanism by which a stereolithography apparatus, a specially built 3D printing system, transforms liquid plastic into solid pieces. Around the world, the stereo-lithography technique is used for a variety of applications. Aside from designs, the technique has some critical nuances. Because of the accuracy and precision it delivers, the technology is widely used and used in most technical setups. 

It is a 3D printing technique used in industry to produce concept models, beauty designs, and complicated parts with complicated geometries in as little as one day. It allows for a diverse range of textures, exceptionally high aspect resolutions, and high-quality surface finishes. 

Process of Stereolithography

Through an ultraviolet laser fired onto the layer of a liquid thermoset resin, the sheets of the support structures are drawn first, followed by the part itself, by the Stereolithography system. After imaging a patch on the glue board, the building frame lowers, and a recoating bar runs around the platform to add the next coat of glue. The procedure is replicated layer by layer before the construction is finished. Recently installed pieces are removed from the unit and transported to a lab where solvents dissolve any remaining resins. When the pieces have been thoroughly cleaned, the support systems are entirely replaced. Sections are then subjected to a UV-curing cycle to strengthen the exterior surface of the component ultimately. The installation of any custom or customer-specified finishing is the final step in the SLA process. Parts made in SLA should be used with minimum UV and humidity exposure to avoid degradation.

SLA 3D Printers for 3D Printing

This is the location where 3D items are printed. The printer receives instructions from the G-Code that is fed to it. 3D printing is done one layer at a time. The mirror, which is operated by a robot, is used to focus the laser at the required cross-section of every layer. The detailed cross-section strengthens as soon as the laser strikes the liquid resin. As the coating is finished, the build frame advances and another cross-section is exposed to the treatment laser. The create platform’s movement is defined by the layer height selected for the Stereolithography method. The process is repeated until the final entity is produced. The build platform emerges from the tank after the 3D model has been completed. Extra resin should be poured away. You can now take the model out of the platform and clean up any leftover resin. The entity is finally cured inside a UV oven. This contributes to the highest possible power of these 3D models. As a result, post-processing is a must in the case of any SLA 3D Printing method. There are many reasons why many experts choose SLA over other 3D printing processes. SLA is one of the most common additive manufacturing processes due to its appearance, accuracy, and a variety of other parameters.

 SLA is one of the best 3D printers for professional applications due to its accuracy. It will create templates with the most diminutive possible layer height. Furthermore, you will construct intricate geometries that would otherwise be difficult to produce. 

The essential characteristics of SLA 3D models are Isotropy. As a result, the range is suitable for a wide range of essential applications. Layer bonding is used to produce pieces in 3D printing. The next layer is added to the one before it, and so on. When this kind of binding occurs, the layer gap is noticeable. FDM 3D printers, for example, produce anisotropic bits. Though, this is not the case for SLA 3D printers. The bond between layers is solid and occurs at the molecular scale during the Stereolithography method. This results in high density and isotropic sections. 

Flowing and SLA 3D printers generate continuous art facts. You may construct complex geometries with stable sections or with internal channels to feel the water tightness. This functionality is critical for many uses, such as design and construction. It is appropriate for jobs where air or fluid would flow in a regulated manner. 

SLA 3D printers can provide the most delicate surface finishes, comparable to those produced by immersion modeling and another traditional process. You may also claim it is superior to the majority of the other procedures. All are depicted most stunningly, from precision to finer details. You can see how SLA printers are capable of producing models with the most beautiful looks.

What is digital light processing?

Digital light processing is also called DLP, a video system used in front and secondary projector devices. DLP technology is commonly used for rear projection in televisions, and it is often used in front projectors for business and educational use. DLP is currently available in two primary configurations: 1-chip DLP and 3-chip DLP. Micromirrors referred to as Digital Micromirror Device, are used in Digital Light Processing to project light and color onto a screen. These micromirrors are very thin and are embedded in a semiconductor chip. In general, a micromirror intensity of less than 5.4m is possible. Each of these mirrors casts a single or multiple pixels in the image. In general, the number of mirrors refers to the clarity of the projected image. The rotation of the mirrors enables the DLP system to generate color and greyscale shades that can be used to produce video files. Texas Instruments manufactures all DLP chips. DLP is also a process that can be used in 3-D printing. It prints a 3-D structure developed in 3-D modeling techniques by projecting the things, one layer at a time, onto a liquid and solidifying it. 

 DLP 3D printing equipment employs a traditional light source, such as an electric lamp, in conjunction with a liquid crystal display screen. In DLP printing, a vat of liquid polymer is safely exposed to UV light. The procedure begins with the 3D model being sent to the printer. Each layer is projected by DLP, resulting in an illuminated plane where photopolymerization can take place. Thousands of micrometer-sized LEDs are commonly used as light sources in modern DLP projectors. Their “On” and “Off” systems are independently regulated, allowing for greater XY clarity. Some DLP printers replace the DMD with an LCD screen, which has a significant effect on price. 3D printing machines complete the DLP process. Using so-called “slicing” software, these printers can be sliced into layers in preparation for printing. DLP prints are standard due to their improved accuracy and resolution. This method of 3D printing is helpful for irregular, natural shapes that would otherwise be difficult for other printers, but it is not often used for practical designs because of the mechanical qualities of resin components. 

How does DLP works?

Here are we discussing the process of DPL step by step:

• A 3D printer’s construction system is placed within a tank packed with liquid photopolymer. The distance between the construction platform and the tank is around one layer deep.

• A ray of light from the light source is permitted to travel after the build platform has been appropriately placed by selectively treating and solidifying the photopolymer resin, these rays of light from the next coat. The light ray passes along a fixed road. Galvanometers are very useful in this situation. Since the direction is predetermined, galvanometers are mounted at regular intervals to observe it. Following the solidification of one sheet, the procedure is repeated on the other one.

• As soon as one layer’s solidification is complete, the build platform moves to a safer distance. The sweeper blade is continuously recoating the surface as the build platform moves.

• Post-processing under light rays is needed for parts that need extremely high thermal and mechanical properties. This is achieved in the fourth step, which is often optional. 

Difference between SLP and DLP

  • There is an advantage of using a DLP 3D printer over an SLA printer. The distinction between them is that of pace. DLP printers are easier to use and make prints than SLA 3D printers.
  • While a DLP 3D printer operates a digital projection screen, the resolution of the print is directly proportional to the resolution of your projector. The higher the resolution of your light ray, the higher the resolution of your commodity. This is not the case for the SLA technique. Higher resolutions can be achieved by using much less expensive cameras.
  • SLA printers are available in any price range, while DLP printers are not as commonly available, especially to small businesses, due to their high cost.
  • DLP and SLA printers have one thing in common: they all use resins. As a result, they can be used interchangeably in most cases. 
  • In contrast to DLP 3D printing, SLA 3D printing is more precise and produces higher-quality prints.
  • The DLP 3D printer is quicker and significantly reduces 3D printing time.
  • DLP is better suited to creating one-off tiny and complicated pieces, while SLA is better suited to printing several complex parts at once.
  • DLP is helpful for quickly printing large parts with little detail, while SLA is ideal for printing large parts with technical aspects.


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