Updated: Jun 10, 2019
3D printing is the process in which material is solidified into layers, creating a part from a computer model. This technology has the power to eliminate design restrictions based on traditional tooling methods and reduce the waste generated during these processes (material is added instead of cut away). Additive Manufacturing (AM) encompasses 3D printing techniques, where materials such as metals, plastics and even concrete can be used. 3D printing is also commonly used for Rapid Prototyping (RM) where concept designs are produced quickly without the set-up costs for tooling in large scale manufacture.
Complex lattice shape produced using 3D printing technology. Source: Autodesk
Types of 3D Printing:
SLA is the oldest 3D printing technique (1980s) in which a polymer is created in layers by photopolymerisation (polymer molecule chains linked by light). The molecules are first in liquid form and fuse together to form a 3D solid from a CAD model.
Source: University of Leeds
Selective Laser Sintering (SLS)
SLS is an AM technique that uses a laser to compact and solidify powdered material, without the material melting. It is commonly used to produce full scale models for RM.
Source: 3D Print Today
Selective Laser Melting (SLM)
SLM uses a laser to instead melt and fuse powdered material together in layers to build up a 3D solid.
Source: University of Alibama 3D Printing
Digital Light Processing (DLP)
A DLP printer also cures polymers in a photo-reactive process using a digital projector as a light source. Printers are bigger due to the projector and the technique is not as common as SLA.
Source: 3D Printing Industry
Electronic Beam Melting (EBM)
EBM uses an electron beam instead of a laser to melt and fuse powdered material together similarly to SLM. However EBM can be a quicker process as separate areas can be heated simultaneously but it is more expensive.
Source: 3D Printing Industry
Laminated Object Manufacturing (LOM)
LOM involves layers of laminated sheet material being repeatedly glued together and cut down to size. This method produces waste material which is cut away from the finished part but is a fast and cheaper method of 3D printing.
Fused Deposition Modeling (FDM)
FDM or Fused Filament Fabrication (FFF) uses a support structure upon which a melted thermoplastic is extruded onto, through an extruder head. It is deposited in layers building up a 3D solid. This is the most common 3D printing process since machines are much cheaper than those used for photopolymerisation.
Source: Research Gate
3D printing now opens doors to completely redesign components and creating complex shapes that could previously never have been manufactured. Such designs can prove to be lighter and stronger which has to drastic implications. Less material used on aircraft will mean better fuel economy and lower CO2 emissions. Stronger 3D printed materials could replace those used in construction.
The economy of 3D printing currently prohibits it being widely used. Companies cannot rely on economies of scale as with traditional manufacturing methods as large investments in set-up and tooling are required. Except for prototype design, it is not currently cost effective for small scale use meaning the technology will still be pioneered by industry leaders for the time being.
Break-even analysis of 3D printing vs traditional manufacturing. Source: DII4
Innovation is also slowed down by stringent regulations, especially in the aerospace industry where safety is paramount. Although it can be seen that more 3D printed components are being used, their implementation is slow.
In my opinion 3D printing will revolutionise manufacturing in a range of industries. In aerospace GE are already producing engines such as the Advanced Turboprop which massively reduces the number of tooled components in an engine from 855 to 12 3D printed ones! In the automotive sector 3D printing has been used for some time to produce rapid prototypes of components. A recent project at work involved a late change to a polypropylene bracket used on a bumper system to improve assembly. SLS was used to quickly produce this resulting in the cost saving of not having to retool. Although now the cost of printers provide barriers to entry, these are likely to come down over time as with all new technology and it will become more widespread.
Components can be generated from a CAD model to physical model using a range of materials Source: Quartz