3D printing scales up


3D printing scales up

Digital manufacturing: There is a lot of hype around 3D printing. But it is fast becoming integrated with mainstream manufacturing

Sep 7th 2013 |From the print edition

PEEK through the inspection windows of the nearly 100 three-dimensional (3D) printers quietly making things at RedEye, a company based in Eden Prairie, Minnesota, and you can catch a glimpse of how factories will work in the future. It is not simply that the machines, some as big as delivery vans, run day and night attended by just a handful of technicians. Instead it is what they are making that shows how this revolutionary production process is entering the manufacturing mainstream.

3D printers make things by building them up, a layer at a time, from a particular material, rather than removing it by cutting, drilling or machining—which is why the process is also called additive manufacturing. There are many ways in which this can be done (see article), and with only a tweak of software each item can be different, without the need for costly retooling of machines. This has made 3D printing a popular way to make one-off items, especially prototype parts, mock-ups, gadgets and craft items.

And that is about all that 3D printers are good for, reckon the doubters. Chief among them is Terry Gou, the boss of Foxconn, the world’s largest contract manufacturer of electronic goods, which makes many of Apple’s products in China. He thinks 3D printing is just “a gimmick” without any commercial value in the manufacture of real finished goods, and he has vowed to start spelling his name backwards if proved wrong.

Mr Gou (or should that be Uog?) is right about one thing: additive manufacturing is not about to replace mass manufacturing. Even though the technology is improving, the finish and durability of some printed items can still fall short of what producers require. And nor can 3D printers crank out zillions of identical parts at low cost, as mass-production lines can. Nevertheless, 3D printers have their virtues, which is why they are starting to be used by some of the world’s biggest manufacturers, such as Airbus, Boeing, GE, Ford and Siemens.

The market for 3D printers and services is small, but growing fast. Last year it was worth $2.2 billion worldwide, up 29% from 2011, according to Wohlers Associates, a consultancy. As producers become more familiar with the technology, they are moving from prototypes to final products. Last year Wohlers reckons more than 25% of the 3D-printing market involved making production-ready items.

Some of those parts are taking shape in RedEye’s printers. In many cases they are low-volume items, such as components used to build specialist pharmaceutical or paper-making equipment. Other components, such as 3D-printed tools and jigs, will actually enhance mass-production: BMW’s assembly-line workers design and print custom tools to make it easier to hold and position parts. 3D-printed plastic moulds and dies are also being printed to help set up and trial new production lines. Some of these printed parts are even used as temporary stand-ins for broken steel tools, which can take weeks to replace.

Hard-to-find spare parts are also being 3D printed, in one case helping a large American airline to get some of its aircraft back into the air. The carrier was frequently having to ground its ageing McDonnell Douglas MD-80 jets because of leaking toilets. Production of these aircraft ceased long ago, and the airline was struggling to find spare parts. Its new plumbing is now being 3D printed in an aerospace-grade plastic (which does not ignite or produce noxious fumes if burned).

As 3D printers get better and printed materials improve, the quality and finish of prototypes is becoming harder to distinguish from things made in traditional factories, says Tim Thellin, RedEye’s manager. Despite the hype around desktop 3D printers aimed at hobbyists and consumers, it is the big, industrial-grade printers that are working the hardest as demand grows for printing large items, which are tricky to make with conventional methods such as plastic injection-moulding, says Mr Thellin. One example is body panels for specialist cars. These can have complex shapes, consolidating individual components that previously had to be assembled.
The inspection windows of some of RedEye’s 3D printers are covered, because these machines are making defence-related items, or their work is commercially sensitive. One that is on view is a machine printing parts for the 3D printers produced by RedEye’s parent company, Stratasys. It and another firm, called 3D Systems, are the market leaders in 3D printers.

3D Systems, based in South Carolina, also has plenty of examples of ways in which 3D printers are being used to produce finished products. An early adopter of the technology has been the health-care industry—a field in which mass customisation is useful, because every patient is different. Millions of hearing-aid shells have been 3D-printed from scans of patients’ ear canals, says Cathy Lewis, 3D Systems’ marketing chief. Initially the shells were cast from 3D-printed moulds, but with the development of printable biocompatible plastics that do not irritate the skin, they are now printed directly.

In another example, 3D Systems has worked with Align Technology of San Jose, California. Instead of using metal braces for straightening teeth, Align produces sets of transparent plastic “aligners”. A scan of the patient’s mouth is used to devise a treatment plan, which in turn generates a digital file which is used to 3D-print a set of 20 or so moulds. Each mould is slightly different, and from them a series of clear plastic braces is cast. When worn over several months, each brace steadily moves the patient’s teeth into the desired position. Last year Align 3D printed 17m of them.

Flying high

The aerospace industry, with relatively low volumes, is also embracing 3D printing. Production parts tend to be non-critical items, but that will change. Today, a typical F-18 fighter jet is likely to contain some 90 3D-printed parts, even though the F-18 has been in service for two decades—since before 3D printing took off. This is because replacement bits, like parts of the cockpit and cooling ducts, are now 3D printed. The F-35, a new strike aircraft entering service in America, has around 900 parts that have been identified as suitable for additive manufacturing, says 3D Systems.

The world’s biggest manufacturer, GE, has no doubt about how important additive manufacturing will be in many of its divisions, from energy to health care. And it intends to keep much of that technology in-house to maintain a competitive edge. In November 2012 GE bought Morris Technologies, a firm based in Cincinnati which has been one of the leaders in providing additive manufacturing services to industry. Among other things, Morris has made lightweight parts for unmanned aerial vehicles. What attracts GE to the technology is its potential to make complex, lightweight components, which are not easily manufactured by traditional means, out of exotic materials. By 2020 GE is expected to be printing tens of thousands of parts for its jet engines alone.
None of this is lost on the Chinese. Officials in Beijing see additive manufacturing as a way to upgrade their own manufacturing base as the country’s labour costs increase and some offshored production moves back to America and Europe. Although it is not yet as advanced as America in 3D printing, China has big ambitions.

“3D printing is not competing with conventional manufacturing, but is hybridising with it.”

Plenty of 3D printing in China dovetails with traditional factories. Beijing Longyuan Automated Fabrication System, for instance, uses a form of 3D printing called laser-sintering to produce moulds out of specially treated foundry sand. The moulds are then sent to a traditional foundry to cast metal parts in the old-fashioned way. The use of 3D printing means all the parts needed for a prototype car engine can be produced in a couple of weeks instead of several months.

Some of the world’s biggest 3D printers can be found in China. Its astronauts sit in 3D-printed seats which are shaped specifically to their bodies. Engineers working on a Chinese rival to the short-haul jets made by Boeing and Airbus are using giant 3D-printing machines, one of them 12 metres long, to print parts (including wing spares and fuselage frames) in titanium.

Powering up

The value of 3D printing as a production tool will increase further with systems that are capable of printing electrical circuits directly onto or into components. Disney and Xerox are experimenting with such processes, as is GKN Aerospace, a British firm. In a joint project with the University of Warwick, GKN has developed a printing material called “carbomorph”. This has piezoresistive properties, which means its electrical resistance changes when it is squeezed. It can be used to print functioning switches, buttons and sensors.

Optomec, based in Albuquerque, has come up with a way to print electronics which it calls Aerosol Jet. This works by atomising liquid electronic materials into a dense aerosol, which is then focused by a sheath of gas into a beam and deposited in layers. It can produce electrical circuits and components, including wires, resistors, capacitors and semiconductors, with features as small as 10 microns across (a micron is one millionth of a metre). Optomec has been working on printing LED lighting onto wallpaper and control circuits onto the wings of a small drone (which itself was 3D printed by Stratasys).

The company is also working with a number of mobile-phone manufacturers to print circuits directly into handsets. The latest smartphones have multiple aerials for cellular radios, Wi-Fi, Bluetooth, GPS and so forth. They are usually made with a chemical-plating process which is environmentally unfriendly. Optomec can print them directly into the case using a conductive silver ink. A trial system was recently installed on a production line in China.

Eventually it will be possible to print most electrical components directly into a product, predicts Michael Renn, the director of Optomec’s development laboratory. But although the system can print transistors, and could thus produce logic circuits, it cannot print the billions of tiny transistors found in microprocessors and other chips. Those chips would still need to be manufactured in the usual way and incorporated into a 3D-printed product—though Dr Renn is quick to point out that he can use his Aerosol Jet to wire them up.

Additive manufacturing has other limitations. It can be slow—taking several hours to print, say, a body panel for a car. But speed is relative. What may be too slow for a large production run might be fine for a one-off item which would take weeks to make in a machine-shop.

Material costs are also high. Acrylonitrile butadiene styrene, better known as ABS, is the most common 3D-printing material. A mass manufacturer using plastic injection moulding might buy ABS in bulk for about $2 a kilo, but as a bespoke powder or filament for 3D printing it can cost as much as $80 a kilo, says Anthony Vicari of Lux Research, a Boston company that tracks emerging technologies.
In part the price difference is due to higher standards of purity and composition required for 3D printing. But mostly it is because 3D-printer manufacturers require users to buy materials from them and mark up the price, as with the inks for 2D inkjet printers. Mr Vicari thinks this strategy is not sustainable long term as third-party suppliers enter the business. Moreover, some big manufacturers, like GE, are developing bespoke 3D-printing systems which are not dependent on a single supplier of equipment or material.

One spur to the development of the 3D-printing industry has been falling prices and increased competition, after some of the early patents on fused-deposition modelling expired in 2009, notes a recent report by the McKinsey Global Institute. This is what has brought the price of some printers down to below $1,000.

The industry is also consolidating as it scales up. Last year Stratasys merged with Objet of Israel, and in June the company bought MakerBot, based in Brooklyn. In July 3D Systems bought an 81% stake in Phenix Systems, a French provider of laser-sintering in metal, which is something of a European speciality (the leader in laser-sintering is EOS of Germany). Another phase of innovation and increased competition may begin in 2014 when some of the patents on laser-sintering expire. Because laser-sintering is capable of printing things in plastic, metal and ceramics to high levels of detail, it is often used to make finished products rather than mere prototypes.

At your service

Meanwhile, 3D printing is becoming more readily available to people with no equipment of their own through service providers that print objects on demand from digitised plans, such as Shapeways, based in New York, Sculpteo, based in France, and Materialise, based in Belgium. It prints medical implants for surgeons, models of buildings for architects, lampshades for interior designers, custom-made knobs for cabinet-makers and lightweight parts for industrial robots.

If Mr Gou of Foxconn ever has a spot of bother with his own production lines, these firms might be able to help. Clément Moreau, Sculpteo’s boss, tells of a large Chinese manufacturer which was setting up a new production line, but found it was missing some small plastic parts which should have been ordered from an injection-moulding company. Faced with weeks of delay it looked at 3D printing the bits instead. Sculpteo had the first batch of 5,000 parts on their way to China within days. It is yet another example of how 3D printing is not competing with conventional manufacturing techniques, but is instead complementing and hybridising with them to make new things possible. When 3D printing can come to the rescue of mass manufacturing, its place in the factory of the future is assured.

From the print edition: Technology Quarterly


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