3D printing Feature
“The thing that’s preventing wider application in the real world is materials. We need companies to do research into materials resistance and compressive strength.” George Lee
Previously, companies have been in full control of the machines and the materials. But if you can produce and market a print head...” But even if we do see the birth of this
kind of “open source” 3D printing, the factor that’s keeping the technology on university campuses and at the fringes of manufacturing is the range of materials, and the lack of consistent standards and certification. “The thing that’s preventing wider application in the real world is materials,” Lee argues. “Take this ABS plastic — it’s not waterproof, water goes right through it. We need companies to do research into materials resistance, or compressive strength, to give us all the technical information about what we can achieve.” Preumont agrees that there is a lack of
One of eight different cladding modules produced by 3D printing for the tops of columns at Skanska’s 6 Bevis Marks development
Skanska puts 3D printing into practice on City project
Last month, Skanska achieved an industry first by using 3D printing in a live project. It turned to 3D printing bureau Quickparts (formerly CRDM before its acquisition by 3D Systems in August) to resolve the tricky technical issue of cladding tree-like columns for an ETFE roof at a City of London office development. A 3D printing or additive manufacturing technique was used to produce cladding for the tops of steel columns for a roof garden at 6 Bevis Marks. Eight different complex interfaces between roof and column were originally envisaged as cast steel nodes, but Skanska foresaw considerable expense and difficulty. Alternative steel plate options were considered expensive, challenging or aesthetically unsatisfactory. The ETFE roof package was delivered
by specialist Vector Foiltec, and its consultant Adrian Priestman approached High Wycombe-based Quickparts, which produces bespoke parts for the aerospace, defence and medical devices industries. Simon Hammond, regional sales manager,
says the firm has been quietly innovating while others have been noisily discussing. “What people see in the news represents the consumer end of 3D printing, the machines you can buy for the home or office. But we’re a commercial bureau, we
print parts for human bodies or aeroplanes or Formula One cars, and they’re not prototypes. People are adopting 3D printing because of the advantages it brings.” Bevis Marks was an ideal candidate,
because of the complexity and lack of repetition. “With eight iterations, other types of manufacturing would have needed eight moulds, but we produced eight unique shrouds. It comes into its own when a low volume production run [using conventional manufacturing] is too expensive.” Quickparts used a selective laser
sintering machine that fuses layers of powdered Nylon 12 (PA 12) to build up the complex shapes. “We took the CAD file from the architect, then ‘sliced’ it into 0.1mm layers. The laser operates above a movable platform, so it traces one slice of the layer by putting enough heat on the nylon to melt it. Then the platform moves down by 0.1mm, you put on more powder and build it up layer by layer,” Hammond explains. The eight cladding nodes, termed
“shrouds”, were printed in different sections — a process that took about three weeks — then jointed. Finally, the 600m wide, 800mm high nylon shrouds were finished and painted to resemble steel. For more details, visit our news section online at
www.construction-manager.co.uk
interest from the major materials and chemical companies. “In the short term, there is no market for them. But soon there will be a market for the big chemical companies [such as BASF, Henkel or Dow Corning]. They have the technology and materials, they just haven’t thought about putting it in 3D printers.”
Innovative materials This creates considerable potential for new materials to enter the construction lexicon. “You could easily modify the concrete to make it stay in shape as soon as it meets with air, or print a conductive filament into a non-conductive material and instantly your component can light up,” Preumont says. Encouragingly, he says that the R&D team from one major multinational chemicals company has been in touch with iMakr. So where next for 3D printing in
construction? Lee feels that non- structural cladding harnesses its capabilities. “You could 3D print cladding and reduce the weight in comparison with conventional materials, which could produce savings elsewhere in the building,” he says. But BAM Design’s Carter is unsure, as extruded aluminium is fairly light and cheap to produce anyway. “Once you’ve got the die, the expense is in the die, not the fabrication itself,” he reasons.
One application where the panel agree
that 3D printing is likely to emerge as a viable alternative to traditional construction methods is, ironically,
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