The evolution of additive manufacturing
The origins of additive manufacturing can be traced all the way back to the late 1980’s where rapid prototyping began to emerge in the U.S. A process known as Stereolithography was developed, whereby thin photopolymer liquid layers could be built up on top of each other and cured using a solid-state UV crystal laser controlled by CAD (Computer Aided Design). This form of rapid prototyping allowed for fast product development and testing with relatively low costs when compared with traditional prototyping methods.
During the 1990s there was considerable research and development conducted and additive layer manufacturing (ALM) methods such as Laser Sintering and Material Deposition Extrusion were established. Both techniques relying on the process of heating polymer-based materials to just below melting point, before layering and fusing layers together.
Further research led to new additive materials such as thermoset, thermoplastic, and elastomeric polymers. This led to something of a boom at the turn of the 21st century as applications of the technology grew wider and various sectors began to see manufacturing benefits of ALM beyond rapid prototyping.
A major advancement in technology made during the mid-2000’s was the introduction of metallic materials within ALM. Processes such as Laser melting, which was an evolution of early Stereolithography techniques were developed. Advancements in power generation saw fully dense metallic geometry produced using high power electron beams.
Over the last five years, more manufacturers than ever have begun to integrate additive manufacturing into their operations as the technology became more accessible and affordable.
What are the modern-day applications of additive manufacturing?
The value of products and services derived from additive manufacturing is currently estimated to be worth around £4.5 Billion and is forecast to double in size over the next two years.
Manufacturing sectors producing small batch quantities or highly customised products have been the biggest adopters of additive manufacturing. Traditional manufacturing methods still lead the way in sectors where standardised, high volume production is required as 3D printing becomes less cost effective in mass production.
Currently, the most prevalent uses for 3D printing within manufacturing are: Manufacture of functional parts (29%), Fit & finish components (10%) Manufacture of moulds & tooling (10%), Visual proof of concept (10%). Unsurprisingly, the biggest adopters have been in sectors where low volume, bespoke or customised design is needed, such as:
Additive manufacturing has great potential for growth in this sector with intensive research and development into prosthetics and human tissue regeneration on-going. Currently, 98% of all hearing aids worldwide are produced using 3-D printers. The requirement for one off, highly customised products fits perfectly with additive manufacturing techniques.
One of the earliest adopters of additive manufacturing, the aerospace sector is now able to produce many components much faster, cheaper lighter than before. One example is the fuel nozzle for the GE LEAP engine which can now be manufactured 25% lighter than before thanks to 3D printing techniques. The Rolls-Royce Trent XWB-97 engine used to power the Airbus A380 also features the largest aero component ever to be 3D printed. The front-bearing housing measures 1.5m across and contain 48 aerofoil-shaped vane components.
One of the fastest growing 3D printing applications within the manufacturing sector is tooling manufacture. Reductions in cost, lead time and tool functionality make it an attractive alternative to traditional subtractive manufacturing techniques.
Metal mould tools used for cooling in injection moulding would traditionally have cooling channels drilled into the tool in straight lines. Metal additive manufacturing allows cooling channels to be designed to contour the mould, improving cooling performance and extending the life of the mould whilst also reducing material waste.
How much will additive manufacturing grow?
Estimates vary and much will depend on the rate at which new sectors adopt the technology as new applications develop.
According to a report by Statista, the industry is expected to be worth £9.3 billion by 2018 and go on to exceed £15 billion by 2020. If growth so far is anything to go by, this looks highly likely, with the value of additive manufacturing rising from £970 million in 2010 to £5.25 billion in 2016.
What developments can we expect in additive manufacturing?
3D scanning and 3D printing technologies have both been in existence for some time and they can now be combined to produce 3D faxes. An object is scanned by the sender and data uploaded to the cloud. The receiver then downloads this data and creates an exact replica of the original using a 3D printer.
“4D” printing in essence, is exactly the same process as 3D printing, the key difference being the “smart” materials used. Reactive materials can be designed to change size and shape in response to certain stimuli such as heat, electricity, light or water.
This capacity for printed materials to react to their environment without the need for human interaction, batteries, processors, sensors, and motors opens the door for a wide range of applications. Current uses are restricted to self-assembly of products such as furniture which can assume a pre-defined shape once unpacked. Further research and development, however, could lead to widespread application in sectors such as construction, soft robotics and even the medical field.