Known as 3D printing because the machines often resemble office printers, additive manufacturing is the physical realisation of digitally designed ideas through the layering of material. It is one of the core innovations transforming the industrial sector as manufacturers embrace the fourth industrial revolution.
The technology involves the breakdown of a computer-designed 3D model into cross sectional layers. Each layer is then rendered by a 3D printer sequentially to build up the part originally designed.
Unlike many other forms of manufacturing, 3D printing is not subtractive; it does not involve removing material from a mass nor the melting and reforming of material. Instead, it only uses the amount required to produce a part.
Building in layers allows all kinds of unique geometries to be created, making 3D printing ideal for producing bespoke or tailored parts. The current output is generally geared towards very specific and specialised requirements.
“Using traditional mass-manufacturing techniques could prove very expensive in these situations,” says Duncan Smith, director of industrial and production solutions at Canon UK. “3D printing is ideal when the outcome of your project is highly specified and low in volume.”
How 3D printing began
3D printing was first developed as a rapid prototyping technique in the early-1980s, but the machines were expensive and complicated. It underwent a series of developments throughout the decade, including the patenting of stereolithography and selective laser sintering processes.
The early-1990s saw commercial adoption as the technology continued to mature, followed by a wave of hobbyist, cheaper 3D printers in the 2000s and growing hype as the technology became mainstream in the industrial sector. In recent years, the products have shifted into the “prosumer” market.
In the last ten years, in particular, the cost of a 3D printer has reduced drastically, from up to £14,000 to around £300, placing it firmly on the radar of manufacturers around the world. IT analyst firm Gartner expects 3D printer shipments will more than double by 2018, increasing end-user spending to $13.4 billion. McKinsey predicts an economic impact of up to $550 billion by 2025.
This is a transformative technology that will play a key role in enabling the new world of advanced manufacturing
Two-thirds of manufacturers are already using 3D printing in their production systems and 42 per cent expect to adopt it for mass manufacturing in the next five years, according to PwC. Major brands, including BMW, Nike and Johnson & Johnson, are eyeing it up as a means to produce custom parts, while research from Boston Consulting Group anticipates the aerospace, automotive, and medical and dental industries will account for around half the market in 2020.
Perhaps the most well-known adopter of additive manufacturing is multinational conglomerate General Electric, which last year spent more than $1 billion buying controlling stakes in two leading manufacturers of industrial 3D printers, Sweden’s Arcam AB and Germany’s Concept Laser.
GE is using laser-powered 3D printers and other advanced manufacturing tools to make parts and products that were thought impossible to produce using traditional technology. The company is developing the world’s largest laser-powered 3D printer that prints parts from metal powder.
“This is a transformative technology that will play a key role in enabling the new world of advanced manufacturing,” says Mohammad Ehteshami, vice president and general manager at GE Additive.
“Additive manufacturing allows customers to achieve improvements in quality, efficiency and performance of manufacturing operations, and reduction in waste and material consumption. Traditional discrete manufacturing is worth over $15 trillion – if the additive industry replaces just 0.5 per cent of that, it could be a $76-billion opportunity.”
Manufacturers seek several benefits when deploying 3D printing. The advanced capabilities of the technology facilitate the realisation of parts with complex features and geometries previously considered impossible to manufacture.
For a business case, the key selling points are time and cost-savings. Product development time is saved through the immediate realisation of prototypes, which can be produced as functional end-use parts.
With parts produced almost as the finished product, the production of bespoke tooling is no longer required. Continual iterations of a design are also more easily achieved, so testing is completed before any investment in tooling.
Damian Hennessey, director of global sales operations at Proto Labs, a manufacturer of 3D-printed custom parts, also points to the associated environmental benefits. “There can be less wastage of material compared to other manufacturing techniques,” he says.
3D printers must now overcome their own hype and up their speed if mass manufacture is to be achieved. Until then, companies are more likely to complement their current manufacturing facilities with one or two 3D printers, rather than overhaul their processes.
A gradual adoption allows manufacturers to build the knowledge required for large-scale use. “The majority of engineering courses still offer very little, if anything, in way of additive manufacturing content and that needs to change,” says Philip Hudson, UK managing director at Materialise, a 3D-printing solution provider.
This gap in additive manufacturing skills will have to be filled before the true potential of 3D printing is realised, but until then it will continue to gain momentum for producing parts in low volume for specialised applications.
MOUNTAIN BIKES CUT TO SIZE
3D printing is helping cycling enthusiasts overcome an issue that has long existed in the manufacture of high-end mountain bikes, most of which are made from carbon fibre-reinforced resins. The frames have to be moulded, so even the most expensive bikes are typically made in only two or three sizes.
The size of a mountain bike in relation to its rider is one of the most important influencers of quality, and cyclists rarely enjoy the optimum performance and comfort of the product they purchased.
Mountain bike manufacturers are increasingly turning to 3D printing as a solution to this problem. UK-based Robot Bike Co uses additive manufacturing to produce every one of its bikes to match the size of each customer.
Customers can input their body measurements on Robot Bike Co’s website to generate a bespoke design that matches their needs. The parts are then manufactured at a solution centre by FTSE 250 engineering firm Renishaw.
“Additive manufacturing enables each frame to be designed to suit the body shape and riding style of its owner,” says Marc Saunders, director of Renishaw’s global solutions centres. “Each frame is unique and uses a double-lap bonding method to join the titanium lugs to the carbon tubes.”
ADDITIVE GOES OUT OF THIS WORLD
Another emerging method of 3D printing is in the manufacture of certified parts for military and civilian jet engines. Nasa has deployed 3D-printed parts, produced on Earth and flown to the International Space Station.
The method offers the possibility of using lunar or Martian dust combined with water and a binding agent to print buildings and other structures in situ. By using minerals mined and refined on site, metal 3D printing can produce spare parts and other implements without the need for lengthy and costly space transport.
Printable files can reside on computers with modifications and improvements simply transferred to the end point. 3D printing in metals is well on the way to being established as a major part of the manufacturing process.
“Methods involving multiple lasers offer the potential to build larger items, as do techniques like laser metal deposition in the welding process,” says Dr Michael Wilson, technology director at the 3M Buckley Innovation Centre.
Printing in structural materials such as concretes is not only of interest to Nasa, but also to disaster relief agencies for rapid build and deployment of medical facilities and housing in emergency situations.