3D printing is an additive way of constructing three-dimensional objects from scratch. The technical term is additive manufacturing. The process begins with designing an object using Computer-Aided Design (CAD) software. Based on this digital 3D model, a 3D printer creates the object by adding appropriate materials, layer upon layer, until the object is completely formed.

The raw material for each layer is fed into the machine. The material needs to be heated to its melting point, after which the machine deposits it onto the work surface. A range of materials, including metals, alloys, plastics, polymers, glass, and ceramics, to name a few, can be used in 3D printing.

3D printing technology has been evolving since the 1980s. In 1980, Hideo Kodama of Japan's Nagoya Municipal Industrial Research Institute applied for a patent for a photopolymer rapid prototyping system. Kodama published a research article in 1981 and, a few years later, Charles "Chuck" Hull published his research on stereolithography (SLA), which was subsequently patented in 1986.

Alain Le Mehaute, Olivier de Witte, and Jean Claude Andre had filed patents for SLA a few weeks before Chuck Hull. French General Electric Company and CILAS (Laser Consortium), however, abandoned their applications. In 1987, 3D Systems, the company Chuck Hull founded, launched the first commercial SLA (SLA-1) 3D printer.

A technology with potential

Key advantages of 3D printing are design freedom, negligible waste, single-machine production, and reduced labor costs. The 3D technique of adding to an object layer by layer also enables manufacturers to design and build components with new and complex geometries.

Unlike conventional manufacturing processes, which often produce excess material that ultimately goes to waste, 3D printing mostly uses only as much material as is required in the end product. Any excess, if generated, can be recycled. This reduces waste to a major extent.

3D printing offers a one-step production method, with a single machine handling the entire manufacturing process. There is also no need to have each printing process overseen by an exclusive operator. One operator can run multiple machines.

It bears reminding that current 3D printers employ a variety of different technologies. We use the label 3D printing to collectively describe several processes, including Fused Deposition Modeling (FDM), stereolithography, Digital Light Projector (DLP), multi-jet modeling, Selective Laser Sintering (SLS), and Electron Beam Melting (EBM).

Where we are today

2019 was a year of big progress for 3D printing. There's been robust growth in some segments of the 3D printing industry, namely 3D printing materials, especially metals, and end-use parts. An increasing number of manufacturers are looking to use 3D printing technologies for industrial scale production in the hope of lowering costs, improving production speeds, and realizing mass customization.

According to the Wohlers Report 2020, $1.1 billion was invested in 77 early-stage additive manufacturing businesses in 2019. The report highlights the case of the Italian company Isinnova, which responded to the crisis in medical care triggered by COVID-19 by designing and printing respirator valves in less than 2 days.

3D Hubs, an online manufacturing platform, reported that the value of 3D printed pieces grew by 300 percent in 2019. Expanding market reach is due partly to improvements in 3D printer technology and materials, as well as innovative businesses that are spearheading new product development. In 2020, adoption of 3D printing by enterprises is expected to pick up pace, leading to further market expansion.

According to an article in Industry Week, there is considerable potential in the medical domain for the application of 3D printing in creating personalized medical devices and solutions. This is because every individual has unique physiological processes that can benefit from customized applications.

According to Marco Annunziata of Forbes magazine, the 3D printing ecosystem will see rapid growth as more and more companies enter partnerships and collaborations. Improvements in quality, speed, and price of production are necessary, however, if 3D printing is to compete with traditional manufacturing. Currently, industrial 3D printing cannot match the level of repeatability and reliability that traditional manufacturing is capable of.

Current applications

3D printing is no longer used only for prototyping and early-stage manufacturing. Automotive and other industries are using 3D printing technology in production processes. By printing tools, fixtures, and spare and end-use parts as and when needed, automotive manufacturers have lowered stock inventory and achieved shorter design and production runs.

Apart from the automotive industry, other industries that use 3D printing technology include aerospace, consumer goods, defense, medical, railway, and shipping. 3D printing applications span a diverse spectrum, from consumer goods, such as eyewear, footwear, and furniture; to dental products and prosthetics; to industrial products to reconstruction of forensic evidence and architectural models.

Students, designers, architects, archaeologists, and various enthusiasts and hobbyists use 3D printing for their projects, as well as in the pursuit of a hobby or a passion. Architects build models, archaeologists create replicas of ancient artifacts, and vintage car enthusiasts restore old cars using 3D printed parts.

Shortcomings

One of the main disadvantages of 3D printing is machine cost: 3D printers are still expensive in comparison with machines used in traditional manufacturing. Also, some 3D printers have to be customized according to the manufacturer's specifications. 3D printers also use up more energy than many conventional manufacturing machines, so operating cost can be higher.

Material cost is also higher. 3D printing technology is at a stage where only a few types of materials can be used. Often, these cost more than materials used in conventional manufacturing. Speed is also a consideration: Most 3D printers are still slower than traditional manufacturing machines and incapable of industrial-scale manufacturing.

The future of 3D printing

On-site 3D printing is a potential application that can prove very helpful for operations in remote environments. Rapid and on-demand manufacture of supplies can be a huge asset in regions such as oilfields, mines, the high seas, battle zones, and Antarctic bases, where quick and convenient access to machine parts is not possible.

3D printing technology can enable people working at such remote locations to fabricate replacement components on site when required. The technology is still developing, but there are already some 3D printers available that can operate in some remote environments.

Volume manufacturing via 3D printing is already viable in the production of hearing aids, footwear, eyewear frames, and some other simple goods. Many hearing aids available today have been fabricated using 3D printing technology.

Generally speaking, however, the application of 3D printing in serial manufacturing is still quite limited. In most industries, traditional manufacturing processes are still used because it is cheaper, faster, and more reliable.

Another promise of 3D printing is the freedom to print geometrically complex components. Designing and building objects of high geometric complexity requires developed skills and training. Prints can fail, alas, without solid design and 3D printer handling capabilities. This important application of 3D printing technology is still in the development stage.

The most talked-about promise of 3D printing is that it will transform manufacturing. We're not there yet. But, 3D printing technology has progressed and will likely continue to evolve. Today, many manufacturing industries use 3D printing at some point in their supply chain.

With innovation and market competition, it's expected that 3D printers will become less expensive, cost of materials will also decrease, and 3D printers will be able to handle a wider variety of materials. Manufacturers and researchers also expect 3D printers to become faster.

Going forward, it is expected that custom manufacturing will expand, 3D printing technology will be used in mass-scale production in the automobile, medical, aerospace, and other industries, and 3D printers will be capable of operating in a diversity of remote locations.