3D Printing: The Next Revolution?

by Christopher Barnatt, Nottingham University Business School

3D printing is increasingly being heralded as the Next Big Thing. In October 2012, a bureau service called Shapeways opened a “factory of the future” in New York capable of 3D printing up to five million objects a year. In his State of the Union address, President Obama subsequently highlighted the potential for 3D printing “to revolutionize how we make almost everything”. As 2013 progressed, we then saw Nike debut a football boot with a 3D printed cleat, 3D printing support natively integrated into Windows 8.1, Amazon open a 3D printing section, and Staples offer 3D printers in its stores. 3D printing may still be in its mainstream infancy. But no one in manufacturing should ignore its potential, and this has to be doubly true for those whose business involves molding plastic parts.

3D Printing Technologies
So how does 3D printing work? Well, the term ‘3D printing’ is the popular moniker for ‘additive manufacturing’ (AM), and refers to a range of technologies that feed CAD data to a machine that builds up objects in very thin layers. 3D printers first went on sale from a company called 3D Systems in 1986, with the initial models based on a process called ‘stereolithography’ (SL). Here a laser beam is used to trace out and solidify the first layer of an object on a perforated build platform on the surface of a tank of liquid photopolymer. The platform is then lowered very slightly down into the tank, and more photopolymer flows or is mechanically swept across the first object layer. The second layer of the object is then selectively solidified by the layer beam, and the process continues until a complete object has been printed.

Initially objects 3D printed using stereolithography could only be output in brittle resins. But today a fairly wide range of photocurable materials are available. These include rubber-like plastics, many substitutes for ABS and other thermoplastics, flame retardant plastics, totally clear resins, and special photopolymers for dental modelling and jewelry design. There are also now 3D printers that can create objects by solidifying photopolymer layers using a DLP projector rather than a laser. Yet others use an inkjet-style print head to emit a photopolymer that is immediately set solid using a powerful UV light. A few such ‘material jetting’ or ‘polyjet’ 3D printers – including the Connex range from Stratasys – can mix multiple materials in their print head to build objects in many materials simultaneously.

A second major 3D printing technology is ‘material extrusion’. Here, a molten or otherwise semi-liquid material is output from a nozzle that moves on the X and Z axes to trace out the first object layer on the surface of a build platform. As in stereolithography, the build platform then lowers and the process repeats. A typical layer thickness for this kind of 3D printing is about 100 microns.

Material extrusion 3D printers have been built that can manufacture objects in a wide variety of materials, including ceramics, metals, concrete, and chocolate. This said, by far the most common materials used are thermoplastics including ABS, ABSi, PLA, and polycarbonate.

The first 3D printers that extruded thermoplastics were invented by Scott Crump, who established 3D printing giant Stratasys. Crump termed his thermoplastic extrusion 3D printing process ‘fused deposition modelling’ (FDM) and trademarked the term. Because of this, other manufacturers use a range of different names to refer to this kind of 3D printing technology. These include ‘plastic jet printing’ (PJP), ‘fused filament modelling’ (FFM), or ‘fused filament fabrication’ (FFF). In part due to the abundant lexical confusion that mires the 3D printing industry, in June 2012 ASTM International introduced a set of standard terminology that suggested the generic name of ‘material extrusion’ for all such 3D printing technology.

In contrast to 3D printers that solidify a photopolymer or extrude a semi-liquid material, a final major technology category is ‘granular materials binding’. This creates objects by laying down successive layers of a powdered build material. In some 3D printers the granules are stuck together by spraying on a glue in a process generically termed ‘binder jetting’. Alternatively, a laser or other heat source may be used to partially or completely fuse together the particles of a build material in a process generically termed ‘powder bed fusion’.
3D printers based on binder jetting can build objects in a range of materials including gypsum powders, PMMA plastic, or silica sand. The latter allows sand casting molds to be directly 3D printed. The VX4000 binder jetting 3D printer from Voxeljet has a build volume of up to 4m x 2m x 1m. A binder jetting 3D printer from a company called D-Shape can make even larger objects by spraying a binder onto sand that results in a marble-like material for 3D printing parts of buildings.

Depending on their manufacturer, 3D printers based on powder bed fusion use a range of proprietary technologies including ‘selective laser sintering’ (SLS), ‘selective laser melting’ (SLM), laserCUSING, ‘direct-metal laser sintering’ (DMLS), and ‘electron beam melting’ (EBM). The range of possible build materials includes nylon, wax (for lost wax casting), stainless steel, aluminium, nickel alloys, cobalt chrome, iron, and titanium. There are also special composite materials – such as ‘alumide’ (a powdered mixture of nylon and aluminium) – that allow the powder bed fusion of metal-like objects at relatively low temperatures.

Digital Manufacturing Pioneers
Already the industrial application of 3D printing is expanding dramatically. For many years the technology has been used for rapid prototyping (RP), and has practically become synonymous with that term. But increasingly, patterns and final molds are also being 3D printed to assist in the tooling of traditional production processes like rotomolding. This is also the area of 3D printing application that we should expect to develop most rapidly. No 3D printing technology is set to replace the vast majority of applications in which techniques like roto or injection molding are currently utilized. However, increasingly companies are going to be reaping time and cost savings by producing some of their molds and patterns using 3D printers. In August 2013, Stratasys showcased several materials that can be used to directly produce molds.

Beyond rapid prototypes and production tooling, a few pioneers are also starting to 3D print final products or parts thereof. For example, Protos Eyewear is 3D printing spectacle frames by laser sintering a “proprietary mixture of powdered materials”. As Richard Ruddie, the company’s Chief Technology Officer, told me “3D printing is finally beginning to reach a point where both the price and quality of printed materials are comparable to current manufacturing methods. The process allows us a great deal of flexibility. Instead of printing large quantities of one design we can create as many (or as few) variations of styles and sizes as we need. We have also developed software that allows us to custom fit a pair of spectacles to a customer’s specific facial measurements.

Spectacle frames are not traditionally produced by rotational molding! But toys such as dolls often are. Another interesting digital manufacturing pioneer is therefore MakieLab in London. This describes itself as a “new kind of toys and games company” that produces “future-smashing” toys that are “customisable, 
3D printed, locally-made, and game-enabled”. The company’s first products are poseable 10 inch action dolls called MAKIES that anybody can design using a highly interactive app on the makie.me website. Given the sheer number of permutations available, every product shipped by MakieLab is unique.

Like Protos Eyewear, MakieLab manufactures its products using selective laser sintering. As company founder Jo Roach told me in an interview, “We decided to make 3D printed products because the toy industry is ripe for disruption: customisable, personal toys are far more interesting than generic made-in-China toys. They encourage creativity in kids before they even get to the toy store, and for MakieLab they allow local production and fast iteration. Customers can ask for horn rimmed glasses on Monday and we can have them in the store by Friday”.

Other companies already 3D printing final products (or parts thereof) include Nervous System (a studio that produces designer jewelry and lampshades), Bespoke Innovations (who create customized fairings for prosthetic limbs), and ThatsMyFace.com. The latter allows a customer to upload a side and front view of their head, which they then transform into a 3D model. This is then 3D printed in full colour and either put on a standard superhero action figure or turned into a mask or other personalized gift.

Like Protos Eyewear and MakieLab, all of the aforementioned companies are using 3D printers to produce relatively small, relatively expensive and highly customized products. Nobody is going to be 3D printing tens or hundreds of thousands of plastic components anytime this decade or probably even next. But already, where a production run of a few hundred parts is required, 3D printing is starting to compete successfully with traditional molding processes in certain situations.

3D printers are also already starting to be used successfully in the rotomolding industry. For example, in a recent interview, Dru Laws of Seljan Co. enthused about the “fantastic” 3D printer which is already being used in the company’s roto, injection molding, and metals divisions, and which “has already paid for itself”. As Dru explained, “The parts we rotomold are huge, but our customer is having us 3D print small scale versions that they can handle and show in their office and on their trade show booths. The idea is to print one of each of their products, all to the same scale. Then they can show off their product offering from a tabletop. Otherwise, these parts are too big to show their customers all the neat features in the back rather than underneath the product.”
Citing another example, Dru explained that Seljan Co. is currently in the process of making a mold for a new roto customer. “Before we cut the tooling, we printed his product in four sections and assembled it together. We then sent him the 3D prototype. As it turns out, the product didn’t work and he needed to make a quick design change. A few hundred dollars for the 3D print saved him thousands of dollars on a mold that would have been incorrect”.

The Next Revolution?
Consumer 3D printers capable of personally fabricating functional plastic items can already be purchased for a few hundred dollars. Some companies are also radically embracing the opportunities this is creating for the rising ‘Maker Movement’. For example, on 18th January 2013, Nokia released a “3D printing development kit” for its Lumina 820 smartphone to allow “someone versed in 3D printing” to produce a custom casing. By January 24th, Nokia 820 shells – some with functional buttons – were being showcased online and their designs freely exchanged. Even so, I would caution against the view being expressed in some quarters that 3D printing is about to “destroy the capitalist system” by putting the means of production into the hands of the majority.

My own take is that 3D printing will drive a revolution, but one that will complement rather than replace most traditional manufacturing methods. A reasonable guesstimate is that, sometime next decade, 3D printing is likely to be used to directly or indirectly manufacture at least 20 percent of products or parts thereof, and to assist in the tooling-up of a far higher proportion of industrial output. To some my 20 percent figure may sound rather small. But for the companies who currently produce those items that will end up being 3D printed, it will be a revolution, and potentially a somewhat painful one.

For most mass-produced, low-cost items, 3D printing is very unlikely to become cost competitive with rotational molding and other traditional manufacturing methods. Nevertheless, there will be situations where low-cost, non-customized items do end up being 3D printed. For example, in the medium-term, 3D printing is likely to have a very significant impact on product repair, with spare parts for any item able to be stored digitally and printed out as required. NASA is already intending to 3D print spares on the International Space Station and future missions to Mars. Or as Jay Leno recently explained in Popular Mechanics, when he needs a spare part for a 100-year-old car, he already just scans and 3D prints.

Big opportunities will also increasingly exist for products with one or a few 3D printed components. As ThatsMyFace.com already illustrate, a standard toy can already be turned into a customized product by replacing just one part (here the head) with a 3D printed alternative. And there have to be thousands of similar opportunities to add one or a few 3D printed components to items largely made by rotational molding or other traditional processes. Time and again I come across companies who believe that 3D printing final products is a case of “all or nothing”, and this absolutely does not have to be the case.

Another key thing to appreciate is that many 3D printing pioneers will not have to own their own 3D printer. Already bureaus including Shapeways, i.materialise, and Sculpteo allow companies or private individuals to upload a 3D CAD model that will be printed out on industrial grade hardware and returned by courier. Budding designers can also already set up virtual stores on these sites and sell items that are printed-on-demand. On Shapeways alone, already over 8,000 designers are doing just this, and in the process launching products with no investment in stock or tooling whatsoever. Meanwhile, bureau services like RedEye on Demand (from Stratasys) and QuickParts (from 3D Systems) are offering very-rapid-turnaround 3D printing services to industrial clients across a widening range of industries.

As I’ve repeatedly said, none of the developments described in this article are going to replace traditional manufacturing overnight or possibly ever. This said, the ability to additively manufacture objects anytime, anyplace, and anywhere is not something that any forward-looking manufacturer ought to ignore. Back in the early 1980s, the first computer spreadsheets did not destroy the accounting profession. But several decades later, no accountant works in the way they once did. And as 3D printing continues to develop, this is a lesson that none of us needs to forget.