Welcome to the ink-jet age

...chief executive of Z Corporation

Bonding glue
A typical 3D printer costs about $30,000 and uses a 448-nozzle print head to deposit a pattern of bonding glue onto a layer of powder dusted onto an aluminium plate in microscopically thin layers, the glue bonds the powder and forms the object, whilst the un-bonded powder acts as a physical support for the object as it is built. By dusting and printing layer after layer the machine slowly builds up the object using data provided by the CAD software running on the attached computer.

Once the printing process has finished, which typically takes about an hour, the supporting powder is dusted off leaving a hard finished plastic object at an average cost of about $10. This can then be further machined, painted, or used as a mould or pattern for casting plastic or metal objects.

"Time to market is extremely important it is no good just having a good idea it is how quickly you can get that to idea to market otherwise somebody beats you to it, you can try ten different designs with 3D printing allowing you to quickly get customer reaction," says Dr Walter Bornhost, chairman Z corporation comments.

Stereolithography rapid prototyping systems, as 3D printers were known when first developed back in 1986, have advanced enormously. The rather rough jagged products of early machines have given way to smooth surfaced products of almost commercial quality. The machines in use today are desktop devices that can be used in any office environment says Motorola's global prototyping manager Mike Jahnke. "It is so quiet and its so simple anyone can use it."

Today with several competing companies fighting for market share commercial 3D printer prices are rapidly dropping and could soon hit a level that most businesses can afford. There are even rumours of a sub-$1000 home model.

Build living organs
As the price of ink jet based 3D printers drops and the quality of the objects produced improves, the latest generation can even produce multicoloured objects, so the range of applications for such printers grows. Architects are using them to build models of their designs, geologists are using them to build models of geological structures, and surgeons are using them to plan complex surgical operations by producing plastic replicas of the patient's internal organs using data derived from 3D CAT scans. Some biomedical researchers are even using 3D printers to build living organs from an 'ink' of live cells.

Rather than build small plastic models of buildings, an engineer at the University of Southern California's Contour Crafting Centre, Behrokh Khoshnevis, is using a giant 3D ink jet printer to print entire buildings straight from the electronic blueprints using an ink of quick setting liquid concrete. The university has partnered with architects, and construction companies to help Khoshnevis develop this concept. This system he believes will, within a couple of years, be capable of constructing a 200m² building in a single day, including all walls, roof, and conduits for electricity and plumbing. This is an innovation that could completely change the construction industry.

The ink jet is thus rapidly becoming an important manufacturing tool from nanotechnology to construction, and one that will be increasingly important in an era of manufacturing flexibility and product personalisation. It is also a tool that further increases the productivity of manufacturers by facilitating greater automation of the manufacturing process.

Above all, however, the ink jet is a tool which is changing the fundamental process of manufacturing away from the reductive process of cutting an object from a solid block or sheet — whether this is a silicon circuit board or the cylinder block of a car engine — to an additive process where material is added in small quantities to build up an object. It is a change that will not only shake the manufacturing sector to its core, but will also make manufacturing far less polluting and far more responsive to consumer needs.