Printing Power

Pushing the Limits of 3D Printing

Experts tell us that we are now living in the Third Industrial Revolution, a landmark time in which manufacturing is freed from Henry Ford’s mass production line to embrace the new possibilities of made-to-order, one-off production.

3D printing is a driving force behind this march forward. Officially known as “additive manufacturing,” 3D printing seems as though it were taken straight out of a science fiction movie: a single technology that can create an amazing range of objects, from cheap plastic knick knacks to household objects, aircraft engine parts, and even human organs. With over one hundred materials available – from plastic and nylon to metal and concrete – the possibilities are almost endless.

Regardless of the material used or the object produced, 3D printing utilises the same basic process to create a three dimensional object. This process is essentially the same as with a traditional 2D printer – expect 3D printers don’t stop after the first pass, they continue to “print” layer upon layer, moving upward on what is known as the Z-axis. Each of these layers is a thin, horizontal cross-section of the final object, much like layers in a cake that stack one atop another until the cake is completed.

Just like a 2D printer relies on a computer program like Microsoft Word to guide the printing process, 3D printing requires sophisticated software to “slice” the design into the necessary horizontal layers and tell the printer how to print them. In other words, 3D printing allows us to translate a digital file directly into a physical product. The possibilities are mind boggling.

The ground breaking technology has huge implications for the construction industry. Using giant 3D printers, the Chinese company WinSun has already printed ten full-size houses – in just one day. The BBC reports that to build each house, four 10m x 6.6m printers work together to spray layers of quick drying cement mixed with construction waste. Mum’s the word regarding the details – the company won’t divulge anything about its secretive construction process.

Recycled materials and a lack of labour allow the small houses to be produced for rock bottom prices. While admittedly a steal at just $5,000 a home, the bargain price does not buy aesthetics; these dreary concrete boxes have all the charm of a soviet bloc apartment. But, the company insists that these standalone dwellings are just the beginning; although current regulations limit 3D printing to a single storey, WinSun hopes to build bigger and better in the future, with the eventual goal of printing an entire skyscraper.

And in the United States, University of Southern California Professor Behrokh Khoshnevis has been hard at work developing a printing technology called Contour Crafting that has the potential to automate the construction of large structures and sub-components.

Low income, emergency, and commercial housing are some of the most likely candidates for the new technology, although applications are only as limited as the imagination. In fact, not even the sky’s the limit for Contour Crafting – the organisation’s website states that it “will most probably be one of the very few feasible approaches for building structures on the Moon and Mars.” While this may sound fantastical, the system has actually earned accolades – and legitimacy – from both the National Inventors Hall of Fame and NASA.

To build a structure using Contour Crafting the building area is flattened, then an excavator digs trenches around the perimeter that will be filled with concrete. Special rails are laid beside the foundation and the giant printer is lowered on top of them using a crane. These rails will keep the heavy printer from sinking in the mud during the construction process.

Concrete is pumped into the printer, then spilled out in layers to form the walls of the structure. Extremely fast drying concrete is used, so each layer becomes a foundation for the next one. Spaces are left for pipework and electrical systems, which will be installed after the printing process is completed. When the first storey is finished, a robotic arm places a prefabricated metal ceiling on top. The layering process is then repeated to build the second storey. “Using this process, a single house or a colony of houses, each with possibly a different design, may be automatically constructed in a single run,” the Contour Crafting website states.

In Amsterdam, DUS architects is using a massive 3D printer to create a building out of plastic. Canal House, which is inspired by the city’s iconic tall, narrow dwellings, will serve as a research and development project as well as an exhibition site.

A 6 metre tall printer named the Kamermaker, or “room-builder,” prints out huge, honeycomb-structured blocks which are then fitted together like Legos to form the house. Each block is built in painfully slow layers and takes about a week to complete. Canal House’s first block, which makes up one corner of the house and part of a stairway, weighed 180 kilograms.

The unique project does not aim to build a functioning house, but to explore and share the potential uses of 3D printing. In fact, the generous three year timeline will allow the architects to experiment with new technology as it develops and to create and test new materials. The team is currently using bioplastics to build Canal House, the project website reports. Macromelt, a type of industrial glue made of 80 percent vegetable oil, enters an extruder through a funnel and is heated and pressed together to form a liquid. This liquid is carried to the printer head via a heated tube and then released along a programmed path to form the shape of each block.

In theory, the Kamermaker could be loaded with any material that melts at a low enough temperature and quickly re-hardens. “We aim to print with a material that is sustainable, of biological origin, melts at a relatively low temperature, and of course is sturdy and stable,” the Canal House website states. “We are also researching the possibilities of printing with recycled materials: Plastics of course, but we’re also looking into using wood pallets and natural stone waste.”

Projects like Canal House are gaining steam because 3D printing offers some key advantages over traditional building techniques. For starters, 3D printed designs are easily modified, allowing a high level of customisation and detail. As a result, structures can be personalised without adding any extra cost or labour. In addition, the 3D printing process goes directly from raw material to final product – eliminating wasteful steps in between. Transport costs are no longer an issue, since designs can be transferred digitally and then printed locally.

The technology still has a long way to go, of course, and concerns regarding fireproofing, wind loads, and insulation have yet to be fully addressed. The potential is huge, however, and the industry’s pioneers are eagerly forging ahead. Perhaps, in the not so distant future, our children will be unable to imagine a day before buildings were constructed using 3D printing. Like cell phones and the internet, this amazing technology may one day make the leap from the incredible to the ordinary.

Home Automation

Call it ‘domotics,’ and you are likely to receive a blank stare, but refer to it as ‘smart home’ or ‘home automation,’ and you will get a nod of acknowledgement. For the past few years, consumers have heard the word ‘smart’ attached to countless products and services, from food and drink to snacks like popcorn and mobile phones, which no one seems to refer to as a ‘cellphone’ anymore. Yet what, exactly, constitutes ‘smart’?

September 25, 2020, 7:17 PM AEST