3D printing is used in almost every industry, including automotive, construction, dentistry, and jewelry. However, the quality of your 3D prints can be influenced by the 3D printing technology you use.

There are many 3D printing technologies that you can use to create 3D printed objects. The most common include stereolithography, selective laser sintering, and fused wire deposition modeling.

This article discusses the types of 3D printing technologies.

1. Stereolithography (SLA)

Stereolithography or SLA is one of the first 3D printing technologies, and it is still used today. The technology uses the process of vat light curing to create 3D objects.

In SLA, an object is made by exposing a photopolymer resin to light, usually UV light. The process involves pointing a laser beam at a reservoir (vessel) of liquid photopolymer, selectively curing and curing it, and building it up one layer at a time.

Parts printed using this technology are generally dimensionally accurate with smooth surface finishes, although they include support structures. SLA is used in the aerospace, automotive, and medical industries, to name a few.

2. Selective Laser Sintering (SLS)

Selective laser sintering (SLS) is a type of 3D printing technology based on the powder bed fusion process. This technology is primarily industrial and is ideal for complex geometries including negative and interior features, undercuts and thin walls.

Sintering is the process of making a solid mass of material by heating it, but not to the point of melting. The heat source is a powerful laser used to sinter powdered thermoplastics to form functional parts. A common material used in SLS is nylon.

Both SLS and SLA are based on the powder bed fusion process and have a similar mode of operation. But unlike SLA, SLS does not need support structures because the part is surrounded by unsintered powder. Additionally, SLA parts are generally tougher than SLA and have rougher surface finishes than the latter.

3. Fused Deposition Modeling (FDM)

FDM, sometimes referred to as Fused Filament Fabrication (FFF), is a popular 3D printing technology that uses the process of material extrusion. This technology is one of the most cost-effective methods for producing custom thermoplastic parts and prototypes.

An FDM printer builds objects by layering extrusions of molten thermoplastics through a moving, heated nozzle onto the build platform, where it cools and solidifies. Although generally functional, finished items tend to have rough surface finishes and require additional processing and finishing.

FDM is one of the most widely used technologies for home office printer models. For example, you can use an FDM printer to print tabletop miniatures at home.

FDM is one of the few 3D printing technologies that uses production-grade thermoplastics to print parts with excellent thermal, chemical, and mechanical characteristics. The thermoplastic filaments used include polyethylene terephthalate (PET), polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS). Common applications for FDM include 3D printing buildings and making 3D desserts.

Metal Binder Jetting (MBJ) is a 3D printing technology that uses the binder jetting process to fabricate metal objects. Binder jetting forms objects by selectively depositing a binding agent onto a bed of powder material.

In MBJ, a binder is deposited by printheads on a bed of metallic powder, producing objects with complex geometries. The binder “glues” the metal powder together inside and between the layers.

To create an object, layers are dropped on top of each other until the desired object is complete. Once this is complete, you will need to implement post-processing techniques, such as sintering or infiltration, to produce functional metal objects.

You can use this technology with various materials (sand composites, ceramic and acrylic powders), as long as the binder binds them together effectively. Binder Jetting also allows you to add color pigments to the binder to produce full color print parts.

Metal Binder Jetting is a quick process. However, it creates parts with a grainy surface finish that is not always suitable for structural parts. For this reason, the technology is ideal for metal 3D printing and low-cost batch production of functional metal parts.

5. Digital Light Processing (DLP)

Digital Light Processing or DLP is an in-vessel polymerization technique. 3D printing technology works with polymers and is very similar to SLA. Both technologies form parts layer by layer using light to selectively harden the liquid resin in the vat.

Once the parts are printed, you will need to clean them of excess resin and expose them to a light source to improve their strength. Like SLA, DLP can be used to create parts with high level dimensional accuracy.

Both technologies also have similar requirements for support structures and post-processing. Their main difference is the light source; DLP uses more conventional light sources, such as arc lamps.

DLP can also work with a small amount of resin to produce precise parts, saving on materials and running costs. Sometimes, however, 3D prints fail. The good news is that you can still recycle failed 3D prints.

DMLS and SLM are similar to SLS, except these technologies use metal powder instead of plastic to create parts. The process uses a laser to melt particles of metal powder, fusing them together layer by layer. Typical materials used include copper, titanium alloys and aluminum alloys.

Unlike SLS, DMLS and SLM need support structures due to the high temperatures required during the process. You can remove support structures in post-processing.

Additionally, SLM and DMLS end products tend to be tougher and with great surface finishes. A notable difference is that DMLS only heats the metal particles to the melting point, while SLM melts them completely. Another difference is that DMLS can form parts from metal alloys while SLM produces single element parts, such as titanium.

What is the best 3D printing technology for your project?

Several factors should be considered when choosing 3D printing technology, including the material required, the visual or physical characteristics of the final object, and the functionality.

Each 3D printing technology has its strengths and weaknesses that make it more suitable for particular projects.

The most commonly used 3D printing technologies are Stereolithography (SLA), Selective Laser Sintering (SLS), and Fused Deposition Modeling (FDM). This article covers the different types of 3D printing technologies available to help you choose the technique that best suits your needs.

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