What is 3D Printing?

3D Printers Explained

3D printing is a form of manufacturing in which three-dimensional objects are created from a digital source. Also known as “additive manufacturing,” 3D printing “creates physical objects from a geometrical representation by successive addition of materials.”

With the advent of new technologies such as Carbon Digital Light Synthesis™ (Carbon DLS™), an increasing number of industries are using 3D printing because it can produce geometries that traditional manufacturing processes cannot. Products can get to market faster because of rapid prototyping and the lack of upfront tooling required. Today, a variety of objects are made from 3D printers, including sports equipment, medical devices, and dentures.

3D Printing or Additive Manufacturing?

The term additive manufacturing is used synonymously with 3D printing.

With additive manufacturing, 3D objects are created from computer-aided designs by adding successive layers of specialized resins, powders, or filaments via processes like injection molding. This is very different from traditional manufacturing, in which parts are cut out of larger pieces of material such as metal, or in which liquid material is injected into molds.

How Does 3D Printing Technology Work?

3D printing works by using a digital model to create a 3D physical object. While other printers, like inkjets, also create physical copies out of digital files, they do so by printing a 2D image on a flat surface like paper. Conversely, 3D printers use a series of coordinates in digital STL files to create geometrically precise 3D shapes.

To build a physical object with 3D printing, a type of filament, powder, or resin is stacked in iterations of layers until the desired shape is formed. With fused filament fabrication (FFF) 3D printing, the material comes in the form of a 3D printer filament, which is heated and then shaped into layers by the machine.

Printing technologies like stereolithography (SLA) use a laser to cure liquid resin layer by layer into solid objects. In this method, a computer-controlled UV laser traces a design pattern onto the surface of a liquid resin, causing the exposed areas to harden. Once a layer is solidified, the platform moves slightly, and the next layer is traced on top of the previous one.

Types of 3D Printing Processes

3D printing technology has experienced many evolutions since its inception nearly 40 years ago. While early 3D printing technology was used almost exclusively to make prototypes, today it is used in standard manufacturing processes by global leaders in sporting goods, prosthetics, robotics, hearing aids, and more.

Liquid Resin-Based Processes

Stereolithography (SLA)

Stereolithography (SLA) printers use resins known as “photopolymers” as the source material for 3D printing. When the printing process occurs with SLA machines, a laser is directed through the photopolymer, which solidifies the desired shape of the 3D object. During post-processing, the laser continuously hardens individual cross-sections of the photopolymer until the entire 3D object fuses together and is fully constructed.

Digital Light Processing (DLP)

Digital Light Processing (DLP) 3D printers also use photopolymers as their source material. DLP printing differs from SLA printing in the way in which UV light interacts with the photopolymer. With SLA printing, the resin cures one point at a time when it comes into contact with the laser. Conversely, with DLP printing, an entire UV image is cast into the photopolymer, where it instantaneously solidifies into one solid 3D shape.

Our patented Carbon Digital Light Synthesis™ (Carbon DLS™) process is an example of DLP 3D printing.

Material Jetting

With material jetting (MJ), 3D printers construct objects using photopolymer droplets. MJ printers spray photopolymer droplets into specific shapes, which are then hardened into objects with UV light. While MJ 3D printing is similar to both SLA and DLP printing concerning the use of photopolymers and ultraviolet light, it uses droplets, as opposed to entire reservoirs of resin.

Powder-Based Processes

Binder Jetting

Binder jetting is a type of powder-based 3D printing that uses glue to form 3D objects. Like other types of powder-based 3D printing, binder jetting uses a powder bed as the source material. A printer nozzle then passes over the powder bed, where it sprays a binder (glue) onto the powder in extremely precise shapes. This process is repeated as more layers of powder are added on top of one another and the 3D object is finally created.

Selective Laser Sintering (SLS)

Selective laser sintering (SLS) is another type of powder-based 3D printing. With SLS methods, 3D printers use electron beams to solidify layers of powder into 3D objects. As with most other powder-based 3D printing, the raw powder material is generally made from a metal or polymer. By exposing the powder to the laser, a shape is created, while the rest of the powder bed remains untouched.

Direct Metal Laser Sintering (DMLS)

In direct metal laser sintering (DMLS), a powder metal is formed into shapes using a precision laser.

Like other forms of powder-based 3D printing, DMLS starts with a bed filled with metal powders such as aluminum and stainless steel. When heated with a laser beam from the printhead, the tiny particles of metal are welded together into several minuscule layers of material.

Directed Energy Deposition

With directed energy deposition (DED) 3D printing, machines use a powder or wire source material and heat it upon contact with the exterior of an object. DED 3D printers exclusively use metal source composites. While powder metal allows for more precision work, wires offer more efficient use of the metal material. DED methods are most commonly used to repair existing parts, although sometimes used to print new components.

Filament-Based Processes

Fused Deposition Modeling (FDM)

With fused deposition modeling (FDM), 3D printers heat plastic filaments which are then deposited in a succession of layers to build solid objects. Because it is cost-effective, FDM is the most common type of 3D printing process. It is widely used across several industries. The machines work by depositing heated thermoplastics with an extrusion nozzle according to predetermined coordinates set forth by digital models.

Fused Filament Fabrication (FFF)

Fused filament fabrication (FFF) is another name for fused deposition modeling (FDM). As mentioned, these 3D systems form heated thermoplastic filaments into solid objects.

Outfit Your 3D Printing Needs with Carbon

As additive manufacturing processes and materials have evolved, they have moved from rapid prototyping to mainstream manufacturing methods. Unlike many of the other types of 3D printing technology, Carbon DLS is suitable for more than just design prototyping. Not only can you iterate on your designs quickly with prototypes, but those prototypes are printed on the same platform with the same materials as the final product. This means you can scale production, and tweak the design when needed without a tooling change. The Carbon platform’s DLS technology, high-quality materials, and design software enable you to take an idea all the way to production.

3D as It’s Meant to Be

Interested in utilizing Carbon to accelerate product development? Reach out to us at sales@carbon3d.com to learn more!