In the previous articles we have had an introduction to 3D printing, how it works, how long it takes, how much it costs, etc. Now, lets learn about the types of 3D printing processes you can select from:

• Stereolithography (SLA)
• Selective Laser Sintering (SLS)
• Fused Deposition Modeling (FDM)
• Digital Light Process (DLP)
• Materiali Jetting (MJ)
• Direct Metal Laser Sintering (DMLS)

Let’s learn in detail about each method:

• Stereolithography (SLA): SLA holds the position to be the world’s first 3D printing technology that was invented by Chuck Hull in 1986. It is one of the fastest prototyping processes that can create objects from a 3D CAD file in just a few hours. If you are looking for accuracy and precision then this is the best you can select.

How it works: In this process, photopolymers, which are a special type of plastic, are first heated to attain a semi-liquid form that hardens on contact. The printer constructs layer by layer using an ultraviolet laser positioned on X and Y axis mirrors known as galvanometers or galvos. Before every print cycle, a recoater blade moves across the surface to ensure that each thin layer of resin spreads evenly. This way the object is created moving from the bottom to the top. After the process is completed, the object is detached carefully from the surface and goes through a chemical bath to remove any excess resin. For post-cure, the object is rendered in an ultraviolet oven to make it stronger and stable. If required, the object can go through hand sanding for finishing touch, and then it is ready to go for professional painting.

It has become a favored economic choice for many industries like automotive, medical, aerospace, entertainment, and several consumer products.

• Selective Laser Sintering (SLS): This process was developed by an American businessman Dr. Carl Deckard in the mid 1980s. It is a perfect technology for fully-functional, end-use parts and prototypes that require high durability and precision.

How it works: This technology uses high power CO2 lasers to fuse particles together. The laser sinters can use metal, nylon, ceramic, and even glass particles. Firstly, the polymer powder is heated to a temperature just below its melting point, keeping it 0.1mm thick. To begin with printing, a CO2 laser beam starts to scan the surface, then the laser will selectively sinter the powder and solidify a cross section of the object. Similar to SLA, it also uses a pair of galvos to mark the correct location. As the object starts building layer by layer, the platform will move down by one layer thickness in height. The recoating blade will then deposit the new layer of powder when the previous one solidifies. The process is repeated several times to complete the manufacturing.

• Fused Deposition Modeling (FDM): It is the most commonly used and cheapest 3D printing process available that was developed in the 1980s by Scott Crump. It uses thermal plastic materials to print functional prototypes, concept models, and manufacturing aids.

How it works: The CAD data is sliced into multiple layers using special software for the 3D printer to read. Then, the filament is added to the printer and fed through the nozzle in the extrusion head. The nozzle is heated to the desired temperature where a motor pushes the filament. The printer then moves the extrusion head along with specified coordinates, laying down the molten material onto the build plate where it cools down and solidifies. The printer moves down as the printer lays another layer, the process is continued until the complete object is created. This printing method might require external support that dissolves after the printing is completed. The object is then given finishing touch with hand sanding and painting to give a smooth finish.

Industries like mechanical engineering and part manufacturers use this technology. For example, brands like BMW and Nestle use FDM technology.

• Digital Light Process (DLP): It is one of the oldest 3D printing technology created by Larry Hornbeck in 1987. It is very much similar to SLA as it works on photopolymers. Although, one major difference between the two of them is that DLP uses a digital light projector to flash a single image of the layer at once. Being projected on a digital screen the layer is composed of square pixels called voxels, which helps in achieving the print faster as compared to SLA.

DLP technology produces robust and high resolution models every time for complex and detailed designs. It reduces waste and keeps the printing cost low.

• Multi Jetting (MJ): It is a new version of a traditional technique called wax casting which was used by jewelers to produce high-quality and customized designs. Today also they are mainly used by the dental and jewelry industries.

How it works: It is one of the simplest 3D technologies available. You just have to upload the CAD file to the printer, the rest, the printer takes care of. The nozzle sweeps the heated wax evenly across the aluminum platform in layers, which cools down and solidifies with the help of UV light. After the complete object is built-up, it can be removed using hands or powerful water jets. No other post-curing is required in this technology.

• Direct Metal Laser Sintering (DMLS): It is also known as Selective Laser Melting (SLM). This process is best for those who are looking for precision, durability, and light weight parts.

How it works: This process is very much similar to the SLS (Selective Laser Sintering), discussed above. The major difference is that it completely melts the metal powder whereas SLS only sinters it i.e., partly melts it. After one print layer, the object lowers by the thickness of one layer, and the next layer is added. After the process is completed, you can remove the object manually and dust off the unused powder. It produces stronger objects leaving fewer or almost no voids.

This technology is popular in the aerospace and medical orthopedics industry. It is an expensive technology, so it is used mainly by researchers and universities.

Above mentioned types of 3D technologies is just a brief of what 3D technology can do. For you to select the right 3D printing process you need to know about all the pros and cons of each technique and be clear about your requirements. 

Once you are clear with which process to choose, grab the 3D printer for yourself, you can check out our wide range of 3D printers here.