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.”
3D printing is used for manufacturing purposes by a wide variety of demographics:
- Medical Professionals
With the advent of new technologies such as Carbon Digital Light Synthesis™ (Carbon DLS™), an increasing number of industries are taking notice of 3D printing and the various providers of it. Today, a variety of objects are made from 3D printers, from sports equipment to medical supplies.
In this article, we will provide a basic overview of 3D printing as well as the most popular production processes and materials.
3D Printing or Additive Manufacturing?
The term additive manufacturing is used synonymously with 3D printing.
With additive manufacturing, 3D models are created from computer-aided designs by adding successive layers of specialized resins, powders, and filaments, via processes like injection molding. This is quite different from traditional manufacturing, where parts are cut out of larger pieces of material, such as metal.
Because additive manufacturing builds printed parts from small materials, instead of cutting them out of large pieces, it doesn’t produce nearly as much waste as subtractive manufacturing. Due to its efficiency, additive manufacturing is used in most major supply chains today, including automotive, aerospace, and healthcare.
How Does 3D Printing Technology Work?
3D printing works by using a digital model to create a 3D physical object. While normal 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.
Other 3D printing technologies like Digital Light Processing (DLP) use resin and UV light to create precise geometries.
Types of 3D Printing Processes
As 3D printing technology has been around for nearly 40 years, it has experienced many evolutions since its inception. 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.
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 shined 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 DLS™ process is an example of DLP 3D printing.
With material jetting (MJ), 3D printers construct objects by way of photopolymer droplets.
MJ printers spray photopolymer droplets into specific shapes, which are then hardened into objects by way of UV light. While MJ 3D printing is similar to both SLA and DLP printing concerning the use of photopolymers and ultraviolet light, it differs with the use of droplets, as opposed to entire reservoirs of resin.
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.
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 as 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.
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 seen 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 established parts, although sometimes used to print new components.
Several Types of 3D Printing Materials
Manufacturers have developed a few key 3D printing composites to power the many types of 3D printers on the market today.
Polylactic Acid (PLA)
Polylactic acid (PLA) is a popular thermoplastic commonly used as source material in fused filament fabrication (FFF) 3D printing. Like other materials used in FFF/DLM 3D printing, PLA is formed into filament spools to be used in additive manufacturing.
PLA is a popular 3D printing filament because it is low cost and commonly made from renewable sources such as corn starch. Another reason PLA has gained such popularity is that it can be used for printing at relatively low temperatures.
Polyethylene Terephthalate Glycol (PETG)
Polyethylene terephthalate glycol (PETG) is another filament commonly used for 3D printing. PETG is a copolyester that is modified by glycol, which becomes malleable enough to print at high temperatures. Due to its makeup, PETG has a glass-like appearance.
Manufacturers enjoy working with PETG because it is known to be extremely durable and heat resistant. That being said, objects printed with PETG are much stronger than those printed with PLA.
Nylon filament is a highly durable 3D printing composite that is also known as “polyamide.” Because of its strong mechanical properties, nylon filament is commonly used to print heavy-duty components such as bearings and gears.
Nylon filament is popular with 3D printing manufacturers because it is strong enough to be formed into end-use products. Therefore, objects printed from nylon filament have high functionality and durability in both consumer and industrial markets.
Outfit Your 3D Printing Needs with Carbon
3D printing is a diverse manufacturing process used to create solid objects from digital sources. Also known as additive manufacturing, 3D printing is used in a number of notable industries, from the medical field to the automotive space, and even has its place in ceramics.
As additive manufacturing processes have evolved, they have moved from rapid prototyping to mainstream manufacturing methods.
Carbon is a leading 3D printing services company that helps businesses manufacture better products and decrease their lead times. With our 3D printing network, we lease cutting-edge 3D printers with on-demand customer service.