What is 3D Printing?7 types of 3D Printing processes

• Fused Deposition Modeling (FDM): material is heated and then deposited in controlled quantities directly on previous layers. Eventually layers are built up to complete the entire part.
• FDM materials include ABS, PC-ISO polycarbonate, casting wax, elastomer, polyester and others.

Industries

• Automotive • Commercial • Medical • Aerospace • Consumer

Pros

• Variety of office-friendly materials available
• Low maintenance costs
• Some newer machines offer water-soluble supports

Cons

• Generally a slower process than Stereolithography (SLA) and Selective laser sintering (SLS) 
• Detectable layering requires finishing
• Support within process needed

• VAT polymerization uses a vat or tank of liquid photopolymer resin, out of which the model is constructed layer by layer.
• Stereolithography Apparatus (SLA) uses an ultraviolet (UV) as the light source.
• Digital light processing (DLP) uses a conventional light source, such as an arc lamp with an LCD panel.

Industries

• Medical • Consumer • Dental • Art and design • Jewelry •Automotive (only DLP) • Aerospace (only DLP)

Pros

• Provides an excellent combination of speed, accuracy, and surface finish (almost layerless)
• No need for post-finishing

Cons

• Limited material selection and properties
• Raw material isn’t pleasant to environment
• Photopolymer exposed to light can become brittle

SLS/SLM are interchangeable terms that refer to a laser-based 3D printing process that works with powdered materials. The laser is traced across a powder bed of tightly compacted powdered material, according to the 3D data fed to the machine.

Industry

• Aerospace • Automotive • Consumer • Commercial • Dental copings • Medical instrument

Pros

• The powder bed serves as an in-process support structure for overhangs and undercuts. Complex shapes can therefore be manufactured without support structures.

Cons

• Due to high temperature, cooling times can be long
• Some applications still necessitate infiltration with another material to improve mechanical characteristics

This method is similar to SLM but uses an electron beam as a heat source. This means the procedure needs to be carried out under vacuum conditions.

Industry

• Aerospace • Automotive • Industrial • Medical

Pros

• Has the capability of creating fully-dense parts in a variety of metal alloys, even to medical grade
• Wholly safe and eco-friendly

Cons

• Not able to compete in the production of complex geometries and the build size is limited to the size of the feedstock

A 3D printing process whereby the actual build materials (in liquid or molten state) are selectively jetted through multiple jet heads.*

Industry

• Jewelry • Aerospace • Dental • Medical

Pros

• Allows for the simultaneous deposition of a range of materials, which means that a single part can be produced from multiple materials with different characteristics and properties
• A very precise 3D printing method, producing accurate parts with a very smooth finish

Cons

• Due to the type of material, parts are rather fragile. The build process is slow

*The materials tend to be liquid photopolymers, which are cured with a pass of UV light as each layer is deposited.

The material being jetted is a binder, and is selectively sprayed onto a powder bed of the part material to fuse it one layer at a time to print the required part.

Industry

• Food • Consumer • Commercial • Industrial

Pros

• A range of different materials can be used, including ceramics and food
• T ability to easily add a full color palette which can be added to the binder
• Do not need support because the powder bed itself provides this functionality

Cons

• Not as strong as the SLS process
• Requires post-processing to ensure durability

Sheet Lamination (SL) builds parts layer -by -layer using standard copier paper. Each new layer is fixed to the previous layer using an adhesive, which is applied selectively according to the 3D data supplied to the machine.

Industry

• Commercial and art • Consumer

Pros

• Produces full color 3D printed parts
• Does not need post-process

Cons

• Dimensional accuracy is slightly less than SLA
• Difficulty in producing hollow parts