3D printing and digital manufacturing. Is this the future of design?

Introduction

In the last years, the huge popularity of 3D printing and digital manufacturing and the great expectations it brought have caused mixed reactions in the design world.

On one side, there are those looking at it at the “Holy Grail” that is going to positively change the future of designers forever. On the other side, some deem it a frontal attack against craft skills and human-oriented design.

Whatever your opinion on it, the dream of a technology that could allow small design firms and designer-makers to create low-volume products in-house, without relying on external manufacturers and 3rd-party services, seems closer than ever. But, is it so?

To help our readers know what opportunities 3D printing (which “professionals” actually call addictive manufacturing) can offer today to designers and producers, we have prepared a short guide presenting its most popular technologies and what they can do to date.

In brief, there are five main 3D digital manufacturing technologies available to small manufacturers and designer-makers, as of 2018.

CNC Milling

Even if they are not 3D printing devices – since they use subtractive manufacturing while three-dimensional printing is always an additive manufacturing process – CNC milling machines are nevertheless one of the most popular solutions to digitally make limited-series and unique pieces. They consist usually of a 3, 4 or 5-axis milling device – driven by a PC and a CAM software – which “carves” three-dimensional objects from a solid block of various materials – plastic, wood, metal and so on, depending on the machine type and the characteristics of the milling cutter.

The main advantages of CNC Milling are that it can work a wide range of industry-grade materials preserving their typical mechanical properties and durability and that it is based on a well-known and reliable technology.

The cons are that professional CNC machines, as well as their replacement parts and consumables, are expensive and that they use rough materials in an inherently inefficient way, often producing a large amount of trimmings. Furthermore, CNC milling is rather slow and energy-consuming, and to make hollow objects and undercut is very difficult, often impossible. It is a technology mostly used to make mechanical parts, fashion accessories, and pieces of furniture.

A Canadian 5-axis CNC milling machine for the jewelry industry (NSCNC Mira 6) and a picture of the same machine carving a piece

3D Laser and electron beam printing

3D laser printing machines use the light emitted by a laser to melt powder (either single-component – usually a metal, mineral or polymeric or a mixture of powder and other materials) one thin layer on top of another to make three-dimensional objects, even with moving parts.

Sometimes, especially with polymeric materials, the powder is not fully melted but “compacted” by the laser through a process known as selective laser sintering.

A slightly different technology uses an electron beam, which is more powerful than a laser, to melt metal powders faster.

Pros: it works with a large variety of materials, including stainless steel, aluminum, copper, titanium, gold, nylon, and polyamide; it can produce objects with very complex geometries quickly and precisely; it doesn’t require support structure during manufacturing; pieces often have very good mechanical properties. Cons: equipment and materials for Laser-based 3d printing are expensive (for example, metals should be transformed in an extremely fine powder through a complex and expensive grinding process); energy consumption is often prohibitive; to manufacture medium-size and large objects has been extremely difficult so far; the surface of unfinished pieces is typically porous and require an additional finishing process.

This technology is mostly used to make jewels, in the medical industry, for high-end mechanical parts, and in the aerospace industry.

An M 400-4 laser sintering 3D printer by German company EOS; and a DXV American Standard laser-printed metal faucet

Fused Filament Fabrication

In Fuse Filament Fabrication (also known as FFF), a thin filament of thermoplastic (usually ABS, or polycarbonate) is extruded and deposited in thin layers (about 0.2 mm thick) by a computer-controlled nozzle, bottom to top.

It is the only 3D printing technology almost everyone can afford since equipment and materials are among the less expensive in the 3d printing industry. Consumer fused filament printers, such as the MakerBot Replicator, are currently available at a street price of about $1,200.

Pros: it can use industry-grade materials; manufactured pieces can be relatively large and have good mechanical properties and durability. Cons: it currently processes mainly plastic materials, although different materials (including natural fiber-based biopolymers, metals, concrete, and even food) are currently under test; unfinished pieces have rough surfaces. Applications: used to make limited-series objects – including furniture and garments -, models, and prototypes.

A Replicator 2 fuse filament 3D printer produced by American company MakerBot

Objects made by fused filament printing using a bioFila silk-based biopolymer produced by German company twoBEars

Designed by Iris van Herpen and Neri Oxman in collaboration with Prof. W. Craig Carter, printed by Stratasys, Anthozoa Cape and Skirt, Voltage Haute Couture Collection, 2013. Object Connex multiple-materials; 3-D printed. © M. Zoeter x Iris van Herpen. Photography by Ronald Stoops courtesy of Museum of Fine Arts, Boston. This dress was printed using a variant of FFF called Fused Deposit Modeling or FDM developed by American company Stratasys

Stereolithography and digital light synthesis

Developed in the late 70s, stereolithography is the oldest 3d printing technology. It is conceptually similar to laser sintering but based on different physical principles; it uses indeed ultraviolet light (usually produced by a UV laser) to polymerize liquid photopolymer resins into various types of plastic materials (depending on the photopolymer used). Depositing layers (typically 0.1 to 0.2 mm thick) bottom to top, stereolithography machines can manufacture very complex and detailed objects. More advanced versions of the original stereolithography technology, such as the so-called digital light synthesis, utilize new resins and improved processes to make better-quality products at a lower cost.

Pros: it’s the fastest, more established and widely available of all 3D printing technologies. Cons: it works only with plastic-like materials; manufactured objects have limited mechanical strength and duration, sometimes; photopolymers are expensive.

This technology has been used mostly to make moldings, prototypes, and models; yet, some companies are experimenting it also for medium-scale manufacturing of plastic products, and in the fashion industry.

A $4,000 Form 2 desktop stereolithography 3D printer produced by American company Formlabs

The Bloom lamp by Belgian company Materialise, designed by Patrick Jouin, and whose lampshade is printed as a single piece through stereolithography.

Inkjet 3D and binder jetting printing

In binder jetting several inkjet-like nozzles deposit layers of metal, mineral or plastic powder and layers of liquid binding resin, alternatively. After the powder in excess is removed, the resulting piece has the desired shape but is mechanically weak, typically, and should be further strengthened, for example by infiltration of a strengthening agent, by baking it in a furnace, or both.

Pros: fast and extremely precise (<0.1 mm); production-grade materials, good mechanical properties. Cons: machines and materials are still expensive. Applications: low-volume manufacturing of metal, plastic, and ceramic objects.

A different 3D inkjet technology uses a photopolymer (such as in the PolyJet system) or a plastic powder (for example a polyamide one) and a fusing agent, sprayed by nozzles and solidified by the light of a UV lamp.

Pros: fast and extremely precise (<0.1 mm); good mechanical properties. Cons: machines and materials are still expensive, and it can use plastic-based materials only. Applications: low-volume manufacturing of synthetic-material products, including sports equipment, fashion accessories, shoes, etc.

An HP 3D Jet Fusion 4210 printing system and a sample product manufactured by the same system; images courtesy of HP.

In a nutshell

In most cases, none of the above-mentioned technologies is currently really competitive for even a low-volume production if compared to traditional manufacturing systems. The problem is that 3D printing hardware and materials are still very expensive, and their running costs high.

Speaking of costs and prices is rather difficult since they range from a few hundreds of dollars for a consumer fuse filament printer to hundreds of thousands for an HP professional jet fusion system. There are companies, such as California-based Carbon, that don’t sell their printing systems but rent them for an annual fee of some tens of thousands of dollars.

For final product manufacturing, the most promising 3D printing solutions in a medium-short period are CNC milling (which is not a printing technology, as said) and Fused Filament Fabrication (whose product range is mostly limited to plastic objects); also some improved versions of stereolithography look rather promising.

Therefore, applications for which 3D printing is most used today are currently restricted to rapid prototyping, model making, and production of unique pieces and other high-value items, for the medical, jewelry, and aerospace industry, for example. In such cases, old “analog” manufacturing techniques are often slower, more expansive, and less flexible than digital ones.

Three-Dimensional printing makes sense when it is simply impossible to produce an object differently; for example, when the geometry is so complex that it can’t be made with traditional processes. This is the case of General Electric that is producing fuel nozzles for its LEAP turbofan engine through electron beam metal sintering since their complex shape would be too difficult to be made through analog manufacturing techniques like metal casting.

The 3D printed nozzle for the GE LEAP jet engine is made through electron-beam metal sintering, since its tips’ interior geometry, comprising more than 20 parts, was so complex that it was almost impossible to make it with traditional techniques; photo Adam Senatori for GE Reports, courtesy of GE

Future scenarios and Industry 4.0

If 3D printing of large-volume products is currently in its infancy, in the next future things could be different, particularly for plastic and synthetic objects manufacturing.

If costs of equipment and materials will decrease, it will be indeed possible to produce items “on-demand” without the need of molds, warehouses for spare parts, and large factories, since production could be disseminated into a myriad of smaller manufacturing units, substantially cutting design-to-shelf time, and almost workerless.

An example of upcoming transformations in manufacturing triggered by new production technologies is that of Adidas, which is making soles for its Futurecraft 4D shoe though digital light synthesis printing units in Europe and the United States, instead of producing them traditionally in Asian factories.

Potential advantages for the industrial sector can be expressed by three key-words: customization, dissemination, speed.

Customization, meaning the capability to “tailor” a product on customers’ needs, is greatly enhanced because for a 3D printer to produce a single piece or thousands of identical copies doesn’t make any difference, conceptually; since it doesn’t use molds, standardized spare parts, and so on.

Dissemination is somewhat intrinsic in the “autarchic” nature of digital manufacturing; the same object can be replicated, identical to itself, by hundreds of single machines, each part of a network of production units disseminated across the world and interconnected through the internet. This scenario, more than Industry 4.0, looks like a piecework 2.0, in which there will be no more large factories, crowds of employees, and union representatives.

Finally, Speed means that the time between a product’s conception and its availability in stores can be reduced from months to weeks with 3D printing, according to a number of recent studies, mostly because of the capability of 3D printers to make different products indifferently, and because disseminated production units will be much closer to retail stores, if not directly located into them.

The sole of the Adidas Futurecraft 4D running shoe is one of the first large-volume items produced by 3D printing (namely, Carbon’s digital light synthesis); image courtesy of Adidas

Conclusions

Thus, 3D printing can soon reveal a two-faced personality; on one side, providing great freedom to independent designers and small businesses, who will be able to go from concept to production almost in real-time; while on the other side eradicating entire industrial districts, together with their manufacturing skills and know-how.

Another potential issue is that of copyright protection; if today to replicate somebody else’s product requires some kind of industrial plant (which nevertheless doesn’t totally prevent unauthorized copying, as we all know), tomorrow everyone who’ll possess the geometric model of an item (maybe illegally downloaded from the internet) and a 3D printer could potentially “hack” a product, whether a table lamp or a gun, replicating it ad-lib.

The pros and cons of this scenario also depend on personal opinions and ethical views. Anyway – whether 3D printing will prove capable to enhance creativity and provide new opportunities to open-minded designers, or it will become just an instrument subservient to the needs of big companies – it will be something we will all have to reckon with very, very soon.

Above, a Lotus.MGX lamp, designed by Finnish artist and designer Janne Kyttanen and manufactured by Belgian company Materialise through stereolithography 3d printing; photo courtesy of Materialise