It can take a long time to become an overnight sensation. History is replete with tales of actors, singers, inventors, and the like whose apparent meteoric rise to stardom belied years or even decades of toil. Such is the case with additive manufacturing, commonly known as 3-D printing, which seems to have come out of nowhere the last few years, at least in terms of mass market attention.

3-D printing is expected to enjoy a solid compounded annual growth rate (CAGR) for the foreseeable future—over 100% through 2018, according to Gartner Inc.—and open up huge new markets for material providers, particularly in the plastics arena. By 2019, 3-D printing materials will top $1 billion, with two-thirds of that value coming from the plastics sector, says Markets and Markets, a Dallas-based market research company. And thermoplastic materials for 3-D printing will become a $1 billion business in itself by 2025, according to IDTechEx, a market research company for emerging technologies.

This paper examines the state of the 3-D printing market, with an emphasis on the application and development of plastics as 3-D printing materials. (The terms “3-D printing” and “additive manufacturing” will be used interchangeably here unless otherwise noted.)

Consumer Acceptance Grows

While industrial and medical usage and breakthroughs have steadily been advancing 3-D technology, it’s the recent promise of widespread consumer acceptance that seems to have catapulted the technology to the top of many minds. Service bureaus have started dotting the landscape, and several established industry names have jumped in. With recent and rapid advancements in the various 3-D technologies and materials, objects with incredibly complex geometries and features can now be printed. 3-D printed aircraft parts, candy, toys/games, cars, and even houses have proven the scalability and versatility of the technology.

Additive manufacturing is “a process by which digital 3-D design data is used to build up a component in layers by depositing material,” as defined by ASTM. While industry professionals may draw distinctions, the terms additive manufacturing and 3-D printing have come to be generally interchangeable. Additive manufacturing is distinct from most traditional manufacturing operations which are considered subtractive, i.e., where the removal of material is a key step in arriving at the finished object.

The building of an item in layers yields comparatively less waste in additive manufacturing, and the process has the potential to dramatically compress existing supply chains and cause a substantial disruption to long-established manufacturing industries. While a few distinct processes are driving 3-D printing, it would be short-sighted to say that 3-D printing consists of a finite number of technologies. The concept of additive manufacturing in theory provides for the creation of just about anything from just about anything.

The most popular additive manufacturing processes today can generally be categorized as fused deposition modeling/fused filament fabrication (FDM/FFF), stereo­lithography (SLA), selective laser sintering/direct laser metal sintering (SLS/DLMS), selective laser melting (SLM), laminated object manufacturing (LOM), and 3-D inkjet printing (3-DP).

A Threat to Traditional Plastics Molding?

3-D printing is what’s commonly referred to as a “disruptive technology.” Essentially, any new technology that could adversely impact or displace an existing technology or market could be considered disruptive.

Any technology such as 3-D printing that in theory decentralizes manufacturing and puts it within reach of just about every company and consumer in the world could be considered a serious threat to traditional manufacturing. Traditional plastics molding, for example, is a large-scale operation requiring a large physical and carbon footprint, substantial capitalization, and complex supply chain logistics. 3-D printing poses a threat to all of that, at least on paper, with the possibility that smaller scale production-on-demand companies and individuals might be able to take on manufacturing themselves. 

Of course, forecasts about the impact of 3-D printing are as varied as the technology itself. Noting what digital technology has done to the newspaper and record store businesses, a GE “Look Ahead” report said 3-D printing “is already disrupting business-as-usual in certain niche industries, prosthetics and medical implants among them, because 3-D printing makes customization easier and design processes faster.”The report also noted: “For standardized items, the cost advantage of additive manufacturing may be less significant since the technology does not yet allow high-volume production, while mass manufacturing decreases the average cost.”

No matter the forecasts, many established manufacturers and manufacturing-reliant companies are hardly waiting around to see what happens. In the GE report, GE chief economist Marco Annunziata said that by 2020 “over 100,000 parts will be additively manufactured by GE Aviation, which could reduce the weight of a single aircraft by 1,000 pounds, resulting in reduced fuel consumption.”

Plastics Assume Major Role

While trade-show highlight reels focus on the hardware, industry research firms such as Gartner Inc. are quick to point out that the key driver to the effective, efficient use of additive manufacturing is material selection.

The material of choice for most consumers, service bureaus, and light commercial users—and the primary driver behind today’s 3-D printing surge—is indeed plastic, for several reasons. Many of the early 3-D technology patents have expired (most notably Stratasys’s primary patent for FDM), leading to an open-source revolution in 3-D printing. Numerous mid- to large-sized firms have moved to fill the commercial/industrial demand, and a seemingly endless cavalcade of crowdfunded upstarts intent on driving price points down for mass-market appeal have entered the industry.

FDM/FFM is also based on a proven, simple, and highly adaptable manufacturing concept—extrusion. The extrusion material of choice, plastic, is readily available, comparatively inexpensive, well-established in a variety of extrusion processes, and perhaps most importantly, ubiquitous in everyday consumer life.

While the 3-D printing industry may chart an uncertain track with hardware sales and consumer adoption, most analysts agree that support for the overall sector in the form of materials will remain strong for the foreseeable future. Among the forecasts, Markets and Markets has estimated (in 2014) that the global additive-manufacturing materials market will grow at a CAGR of 20% from 2014 to 2019 to $1.052 billion, with plastics accounting for $672 million of the total in 2019. Europe and Asia-Pacific combined accounted for more than half of the materials market in 2013; while North America was the single dominant geographical player. 

Plastic considerations extend beyond basic polymer selection. Numerous material characteristics such as filament diameter/shape, rigidity, flexural modulus, melting point, and even color dictate which filaments can be used with which machines. The most common plastics used in 3-D printing are polylactic acid (PLA) and acrylonitrile-butadiene-styrene (ABS), and these will likely continue to fuel demand for low-cost consumer-oriented machines. Polyvinyl alcohol (PVA) is used primarily to create support structures for complex geometries in dual-extruding printers. The printed object is submersed in water, which dissolves the PVA. 

Polycarbonate (PC), polyetherimide (PEI), polyamides (PA), and other plastics are also used in 3-D printing, though to a much lesser extent than PLA and ABS. Blended plastics such as PC/ABS, composites, and “digital materials” continue gaining popularity on all fronts. Extensive research continues particularly in the medical and electronic fields.

Stratasys continues to push development of digital materials for use with its PolyJet technology. PolyJet printers function similarly to traditional inkjet printers, using curable liquid photopolymers for the layer-by-layer 3-D build. Digital materials are “composite materials with predetermined visual and mechanical properties,” according to the company, and are created in the 3-D printer by combining two or more base resins. Stratasys claims that “a single prototype 3-D printed on our advanced Connex3 systems can contain as many as 82 distinct material properties, all created in one build.”

On the powder side, development of materials for selective laser sintering has lagged behind the filament and liquid polymer explosion, likely due to an SLS machine’s higher cost and perceived risks associated with its laser device. Germany’s Diamond Plastics unveiled a new HDPE powder for SLS in mid-2014 and a PP powder later the same year. As of early 2015, Quickparts was offering SLS services using nylon, glass-filled nylon, flame-retardant nylon, and durable nylon. One of the advantages of a powder-based system is that the material can be reused.

Proprietary Materials under Development

Much like the 2-D printing space evolved, 3-D companies are looking to generate as much proprietary material business as possible. Recognizing the potential market value of 3-D printer materials, these firms are conducting their own R&D to develop new formulations and standards for their own machines and technologies.

Because many thermoplastics aren’t inherently compatible with 3-D printing for a variety of reasons (e.g., melt temperature and warping without a mold), the R&D field is fairly wide open for 3-D firms wishing to develop their own materials. ABS is one example—while it works well in filament-based extrusion printers, it doesn’t fit as neatly with liquid photopolymer-based units. To bring the desired ABS qualities (toughness and heat resistance) to their PolyJet customers, Stratasys has created “Digital ABS” by combining two materials at the print head.

In February 2015 ColorFabb announced a new filament based on Eastman’s Amphora 3-D polymer, XT-CF20. It’s reinforced with 20% specially sourced carbon fibers. Because the filament is considered highly abrasive, the company recommends discarding brass extrusion nozzles in favor of steel or copper alloys.

Material innovations are extending beyond just the polymers. At the 2015 Consumer Electronics Show show in Las Vegas, MakerBot announced its new line of PLA composites made with metal, wood, and stone. The filaments reportedly will be available in late 2015 and will be compatible with the company’s SmartExtruder.

The rapid development of proprietary 3-D printing materials by the industry’s largest firms hasn’t gone unnoticed—or unchallenged. IDTechEx has called material development “possibly the most contentious issue in the 3-D printing industry today.” 3-D printer manufacturers are increasingly engaging in practices which are perceived by end-users as anti-competitive by locking customers into their own material supplies via key-coding and RFID tagging of material cartridges—an activity which is effectively enabling monopoly pricing of the materials concerned, according to IDTechEx.

Any antitrust implications notwithstanding, providing plastic materials to the mass market for 3-D printing purposes may in many cases require a different approach than supplying the same or similar material for large-scale operations. Even though the 3-D printing materials space is in its infancy, service bureaus, 3-D printer manufacturers, and material suppliers have already recognized the need to convey material property information and relate polymer characteristics to certain desired end-user results. Storage and use of hygroscopic materials like PLA, for example, can become hyper-critical because the production environment may be less controlled. This would be particularly noteworthy when dealing with the consumer market, where novice designers, tinkerers, and home manufacturers with little or no experience in polymer selection, use and handling could comprise a significant part of a material supplier’s business.

Conclusion

Additive manufacturing/3-D printing has begun to gain incredible momentum in markets around the world. While analysts may disagree on the timing and full impacts of the technology, it appears certain that 3-D printing will at the least establish its own niche and complement traditional manufacturing particularly in the plastics sector, creating new opportunities for plastics suppliers, compounders, and distributors.

About the author… David Witt, R&D engineer for Plastics Color Corp., has been with the company for more than six years. He is responsible for new product development and formulated the specialty additives line, including FlamaSol flame retardants, MicroBlok antimicrobials, and MiBatch anti-counterfeiting systems. You can contact him at dwitt@plasticscolor.com.