Fused Deposition Modeling (FDM), also called Fused Filament Fabrication (FFF), is a leading additive manufacturing technique known for its accessibility and versatility. It constructs parts by selectively depositing layers of molten thermoplastic, guided by a computer-controlled nozzle.

The process begins with a solid filament spool. The filament is fed to an extruder, where it is melted and laid down with precision along a pre-programmed path. Each deposited layer fuses to the one below upon cooling, allowing for the creation of complex geometries with minimal waste.

This makes FDM ideal for prototyping, custom parts, and educational applications.

Stereolithography (SLA) is a pioneering additive manufacturing technology that uses a laser to cure liquid resin into solid parts, differing significantly from filament-based FDM. It is renowned for producing parts with the highest resolution and smoothest surface finish among common 3D printing processes.

During printing, a laser beam is guided across a vat of liquid photopolymer resin by a dynamic mirror system, curing precise cross-sections layer by layer. The build platform adjusts its height after each layer is completed.

While its material selection is confined to photopolymers, SLA is unparalleled for applications demanding extreme detail and smoothness, such as prototypes, jewelry, and dental models. As one of the first 3D printing methods developed, it remains a cornerstone of professional additive manufacturing.

Selective Laser Sintering (SLS) is a powder bed additive manufacturing process used to make parts from thermoplastic polymer powders. It is commonly used for functional parts, since SLS printed components have good mechanical properties.

An SLS 3D printer works by sintering areas of plastic powder with a laser. During the process, a thin layer of powder is distributed evenly across the build platform, after which the laser sinters selected areas of the 2D layer. When the layer is complete, the platform is lowered, more powder is added, and the laser sinters the next layer.

When all layers are complete, the part is left to cool. Unused powder is kept to be used again, and the part is cleaned to remove excess material.

Selective Laser Melting (SLM) is a metal 3D printing process that builds high-strength parts layer by layer from fine metal powder. Inside a sealed, inert gas-filled chamber, a powerful laser selectively melts the powder based on the cross-sections of a CAD model.

Once a layer is completed, the build platform lowers slightly, and a fresh layer of powder is spread across the surface to continue the build. Unlike sintering processes, SLM fully melts the metal powder, resulting in parts with excellent mechanical properties and near-wrought strength.

This makes it suitable for highly demanding applications in aerospace, automotive, medical, and more. The technology also allows for the production of complex geometries, internal channels, and lightweight structures that are difficult or impossible to achieve with traditional manufacturing.