3D printing
A three-dimensional printer The 3D printing process builds a three-dimensional object from a computer-aided design (CAD) model, usually by successively adding material layer by layer, which is why it is also called additive manufacturing. The term “3D printing” covers a variety of processes in which material is joined or solidified under computer control to create a three-dimensional object, with material being added together (such as liquid molecules or powder grains being fused together), typically layer by layer.
In the 1990s, 3D-printing techniques were considered suitable only for the production of functional or aesthetic prototypes and a more appropriate term for it was rapid prototyping. As of 2019, the precision, repeatability, and material range have increased to the point that some 3D-printing processes are considered viable as an industrial-production technology, whereby the term additive manufacturing can be used synonymously with “3D printing”.
One of the key advantages of 3D printing is the ability to produce very complex shapes or geometries, and a prerequisite for producing any 3D printed part is a digital 3D model or a CAD file.The most-commonly used 3D-printing process (46% as of 2018) is a material extrusion technique called fused deposition modeling (FDM). While FDM technology was invented after the other two most popular technologies, stereolithography (SLA) and selective laser sintering (SLS), FDM is typically the most inexpensive of the three by a large margin, which lends to the popularity of the process.
Terminology
The umbrella term additive manufacturing (AM) gained popularity in the 2000s, inspired by the theme of material being added together (in any of various ways). In contrast, the term subtractive manufacturing appeared as a retronym for the large family of machining processes with material removal as their common theme. The term 3D printing still referred only to the polymer technologies in most minds, and the term AM was more likely to be used in metalworking and end use part production contexts than among polymer, ink-jet, or stereo lithography enthusiasts.By early 2010s, the terms 3D printing and additive manufacturing evolved senses in which they were alternate umbrella terms for additive technologies, one being used in popular language by consumer-maker communities and the media, and the other used more formally by industrial end-use part producers, machine manufacturers, and global technical standards organizations. Until recently, the term 3D printing has been associated with machines low in price or in capability. 3D printing and additive manufacturing reflect that the technologies share the theme of material addition or joining throughout a 3D work envelope under automated control. Peter Zelinski, the editor-in-chief of Additive Manufacturing magazine, pointed out in 2017 that the terms are still often synonymous in casual usage but some manufacturing industry experts are trying to make a distinction whereby Additive Manufacturing comprises 3D printing plus other technologies or other aspects of a manufacturing process.Other terms that have been used as synonyms or hypernyms have included desktop manufacturing, rapid manufacturing (as the logical production-level successor to rapid prototyping), and on-demand manufacturing (which echoes on-demand printing in the 2D sense of printing). Such application of the adjectives rapid and on-demand to the noun manufacturing was novel in the 2000s reveals the prevailing mental model of the long industrial era in which almost all production manufacturing involved long lead times for laborious tooling development. Today, the term subtractive has not replaced the term machining, instead complementing it when a term that covers any removal method is needed. Agile tooling is the use of modular means to design tooling that is produced by additive manufacturing or 3D printing methods to enable quick prototyping and responses to tooling and fixture needs. Agile tooling uses a cost-effective and high-quality method to quickly respond to customer and market needs, and it can be used in hydro-forming, stamping, injection molding and other manufacturing processes.
History
1970s
In 1974, David E. H. Jones laid out the concept of 3D printing in his regular column Ariadne in the journal New Scientist
1980s
Early additive manufacturing equipment and materials were developed in the 1980s. In 1981, Hideo Kodama of Nagoya Municipal Industrial Research Institute invented two additive methods for fabricating three-dimensional plastic models with photo-hardening thermoset polymer, where the UV exposure area is controlled by a mask pattern or a scanning fiber transmitter.
On July 2, 1984, American entrepreneur Bill Masters filed a patent for his Computer Automated Manufacturing Process and System (US 4665492). This filing is on record at the USPTO as the first 3D printing patent in history; it was the first of three patents belonging to Masters that laid the foundation for the 3D printing systems used today.On 16 July 1984, Alain Le Méhauté, Olivier de Witte, and Jean Claude André filed their patent for the stereolithography process. The application of the French inventors was abandoned by the French General Electric Company (now Alcatel-Alsthom) and CILAS (The Laser Consortium).
The claimed reason was “for lack of business perspective”.Three weeks later in 1984, Chuck Hull of 3D Systems Corporation filed his own patent for a stereolithography fabrication system, in which layers are added by curing photopolymers with ultraviolet light lasers. Hull defined the process as a “system for generating three-dimensional objects by creating a cross-sectional pattern of the object to be formed,”.
Hull’s contribution was the STL (Stereolithography) file format and the digital slicing and infill strategies common to many processes today.In 1986, Charles “Chuck” Hull was granted a patent for his system, and his company, 3D Systems Corporation released the first commercial 3D printer, the SLA-1.The technology used by most 3D printers to date—especially hobbyist and consumer-oriented models—is fused deposition modeling, a special application of plastic extrusion, developed in 1988 by S. Scott Crump and commercialized by his company Stratasys, which marketed its first FDM machine in 1992.
1990s
AM processes for metal sintering or melting (such as selective laser sintering, direct metal laser sintering, and selective laser melting) usually went by their own individual names in the 1980s and 1990s. At the time, all metalworking was done by processes that are now called non-additive (casting, fabrication, stamping, and machining).
although plenty of automation was applied to those technologies (such as by robot welding and CNC), the idea of a tool or head moving through a 3D work envelope transforming a mass of raw material into a desired shape with a toolpath was associated in metalworking only with processes that removed metal (rather than adding it), such as CNC milling, CNC EDM, and many others. But the automated techniques that added metal, which would later be called additive manufacturing, were beginning to challenge that assumption.
By the mid-1990s, new techniques for material deposition were developed at Stanford and Carnegie Mellon University, including microcasting and sprayed materials. Sacrificial and support materials had also become more common, enabling new object geometries.
The term 3D printing originally referred to a powder bed process employing standard and custom inkjet print heads, developed at MIT by Emanuel Sachs in 1993 and commercialized by Soligen Technologies, Extrude Hone Corporation, and Z Corporation.
The year 1993 also saw the start of a company called Solidscape, introducing a high-precision polymer jet fabrication system with soluble support structures, (categorized as a “dot-on-dot” technique).In 1995 the Fraunhofer Society developed the selective laser melting process.
2000s
Fused Deposition Modeling (FDM) printing process patents expired in 2009.26
2010s
As the various additive processes matured, it became clear that soon metal removal would no longer be the only metalworking process done through a tool or head moving through a 3D work envelope, transforming a mass of raw material into a desired shape layer by layer.
The 2010s were the first decade in which metal end use parts such as engine brackets27 and large nuts28 would be grown (either before or instead of machining) in job production rather than obligately being machined from bar stock or plate. It is still the case that casting, fabrication, stamping, and machining are more prevalent than additive manufacturing in metalworking, but AM is now beginning to make significant inroads, and with the advantages of design for additive manufacturing, it is clear to engineers that much more is to come.
As technology matured, several authors had begun to speculate that 3D printing could aid in sustainable development in the developing world.29In 2012, Filabot developed a system for closing the loop30 with plastic and allows for any FDM or FFF 3D printer to be able to print with a wider range of plastics.
In 2014, Benjamin S. Cook and Manos M. Tentzeris demonstrate the first multi-material, vertically integrated printed electronics additive manufacturing platform (VIPRE) which enabled 3D printing of functional electronics operating up to 40 GHz.31The term “3D printing” originally referred to a process that deposits a binder material onto a powder bed with inkjet printer heads layer by layer.
More recently, the popular vernacular has started using the term to encompass a wider variety of additive-manufacturing techniques such as electron-beam additive manufacturing and selective laser melting. The United States and global technical standards use the official term additive manufacturing for this broader sense.
General principles
Modeling CAD model used for 3D printing 3D models can be generated from 2D pictures taken at a 3D photo booth.
3D printable models may be created with a computer-aided design (CAD) package, via a 3D scanner, or by a plain digital camera and photogrammetry software. 3D printed models created with CAD result in reduced errors and can be corrected before printing, allowing verification in the design of the object before it is printed.32 The manual modeling process of preparing geometric data for 3D computer graphics is similar to plastic arts such as sculpting.
3D scanning is a process of collecting digital data on the shape and appearance of a real object, creating a digital model based on it.CAD models can be saved in the stereolithography file format (STL), a de facto CAD file format for additive manufacturing that stores data based on triangulations of the surface of CAD models. STL is not tailored for additive manufacturing because it generates large file sizes of topology optimized parts and lattice structures due to the large number of surfaces involved.
A newer CAD file format, the Additive Manufacturing File format (AMF) was introduced in 2011 to solve this problem. It stores information using curved triangulations.33
Printing
Before printing a 3D model from an STL file, it must first be examined for errors. Most CAD applications produce errors in output STL files,3435 of the following types:
holes;
faces normals;
self-intersections;
noise shells;
manifold errors.
A step in the STL generation known as “repair” fixes such problems in the original model. Generally STLs that have been produced from a model obtained through 3D scanning often have more of these errors.
This is due to how 3D scanning works-as it is often by point to point acquisition, 3D reconstruction will include errors in most cases.40Once completed, the STL file needs to be processed by a piece of software called a “slicer,” which converts the model into a series of thin layers and produces a G-code file containing instructions tailored to a specific type of 3D printer (FDM printers).
This G-code file can then be printed with 3D printing client software (which loads the G-code, and uses it to instruct the 3D printer during the 3D printing process).Printer resolution describes layer thickness and X–Y resolution in dots per inch (dpi) or micrometers (µm). Typical layer thickness is around 100 μm (250 DPI), although some machines can print layers as thin as 16 μm (1,600 DPI).42 X–Y resolution is comparable to that of laser printers. The particles (3D dots) are around 50 to 100 μm (510 to 250 DPI) in diameter.
For that printer resolution, specifying a mesh resolution of 0.01–0.03 mm and a chord length ≤ 0.016 mm generate an optimal STL output file for a given model input file.43 Specifying higher resolution results in larger files without increase in print quality.
3:31 Timelapse of an 80-minute video of an object being made out of PLA using molten polymer deposition
Construction of a model with contemporary methods can take anywhere from several hours to several days, depending on the method used and the size and complexity of the model. Additive systems can typically reduce this time to a few hours, although it varies widely depending on the type of machine used and the size and number of models being produced simultaneously.
Finishing
Though the printer-produced resolution is sufficient for many applications, greater accuracy can be achieved by printing a slightly oversized version of the desired object in standard resolution and then removing material using a higher-resolution subtractive process.44The layered structure of all Additive Manufacturing processes leads inevitably to a stair-stepping effect on part surfaces which are curved or tilted in respect to the building platform.
The effects strongly depend on the orientation of a part surface inside the building process.45Some printable polymers such as ABS, allow the surface finish to be smoothed and improved using chemical vapor processes46 based on acetone or similar solvents.Some additive manufacturing techniques are capable of using multiple materials in the course of constructing parts.
These techniques are able to print in multiple colors and color combinations simultaneously, and would not necessarily require painting.Some printing techniques require internal supports to be built for overhanging features during construction. These supports must be mechanically removed or dissolved upon completion of the print.All of the commercialized metal 3D printers involve cutting the metal component off the metal substrate after deposition.
A new process for the GMAW 3D printing allows for substrate surface modifications to remove aluminum47 or steel.48
Materials
Traditionally, 3D Printing focused on polymers for printing, due to the ease of manufacturing and handling polymeric materials. However, the method has rapidly evolved to not only print various polymers49 but also metals5051 and ceramics,52 making 3D printing a versatile option for manufacturing.
Multi-material 3D printing A multi-material 3D printed toy.
Main article: Multi-material 3D printing
A drawback of many existing 3D printing technologies is that they only allow one material to be printed at a time, limiting many potential applications which require the integration of different materials in the same object. Multi-material 3D printing solves this problem by allowing objects of complex and heterogeneous arrangements of materials to be manufactured using a single printer.
Here, a material must be specified for each voxel (or 3D printing pixel element) inside the final object volume.The process can be fraught with complications, however, due to the isolated and monolithic algorithms. Some commercial devices have sought to solve these issues, such as building a Spec2Fab translator, but the progress is still very limited.53 Nonetheless, in the medical industry, a concept of 3D printed pills and vaccines has been presented.
With this new concept, multiple medications can be combined, which will decrease many risks. With more and more applications of multi-material 3D printing, the costs of daily life and high technology development will become inevitably lower.Metallographic materials of 3D printing is also being researched.55 By classifying each material, CIMP-3D can systematically perform 3D printing with multiple materials.
Processes and printers
Vat photopolymerization
Material jetting
Binder jetting
Powder bed fusion
Material extrusion
Directed energy deposition
Sheet lamination Schematic representation of the 3D printing technique known as Fused Filament Fabrication; a filament a) of plastic material is fed through a heated moving head b) that melts and extrudes it depositing it, layer after layer, in the desired shape c). A moving platform e) lowers after each layer is deposited. For this kind of technology additional vertical support structures d) are needed to sustain overhanging parts
A timelapse video of a robot model being printed using FDM
The main differences between processes are in the way layers are deposited to create parts and in the materials that are used. Each method has its own advantages and drawbacks, which is why some companies offer a choice of powder and polymer for the material used to build the object.58 Others sometimes use standard, off-the-shelf business paper as the build material to produce a durable prototype. The main considerations in choosing a machine are generally speed, costs of the 3D printer, of the printed prototype, choice and cost of the materials, and color capabilities.
Printers that work directly with metals are generally expensive. However less expensive printers can be used to make a mold, which is then used to make metal parts.60ISO/ASTM52900-15 defines seven categories of Additive Manufacturing (AM) processes within its meaning: binder jetting, directed energy deposition, material extrusion, material jetting, powder bed fusion, sheet lamination, and vat photopolymerization.
Some methods melt or soften the material to produce the layers. In Fused filament fabrication, also known as Fused deposition modeling (FDM), the model or part is produced by extruding small beads or streams of material which harden immediately to form layers. A filament of thermoplastic, metal wire, or other material is fed into an extrusion nozzle head (3D printer extruder), which heats the material and turns the flow on and off. FDM is somewhat restricted in the variation of shapes that may be fabricated. Another technique fuses parts of the layer and then moves upward in the working area, adding another layer of granules and repeating the process until the piece has built up. This process uses the unfused media to support overhangs and thin walls in the part being produced, which reduces the need for temporary auxiliary supports for the piece.
Recently, FFF/FDM has expanded to 3-D print directly from pellets to avoid the conversion to filament. This process is called fused particle fabrication (FPF) (or fused granular fabrication (FGF) and has the potential to use more recycled materials.63Powder Bed Fusion techniques, or PBF, include several processes such as DMLS, SLS, SLM, MJF and EBM. Powder Bed Fusion processes can be used with an array of materials and their flexibility allows for geometrically complex structures,64 making it a go to choice for many 3D printing projects.
These techniques include selective laser sintering, with both metals and polymers, and direct metal laser sintering.65 Selective laser melting does not use sintering for the fusion of powder granules but will completely melt the powder using a high-energy laser to create fully dense materials in a layer-wise method that has mechanical properties similar to those of conventional manufactured metals. Electron beam melting is a similar type of additive manufacturing technology for metal parts (e.g. titanium alloys). EBM manufactures parts by melting metal powder layer by layer with an electron beam in a high vacuum.
Another method consists of an inkjet 3D printing system, which creates the model one layer at a time by spreading a layer of powder (plaster, or resins) and printing a binder in the cross-section of the part using an inkjet-like process. With laminated object manufacturing, thin layers are cut to shape and joined together. In addition to the previously mentioned methods, HP has developed the Multi Jet Fusion (MJF) which is a powder base technique, though no laser are involved. An inkjet array applies fusing and detailing agents which are then combined by heating to create a solid layer.68 Schematic representation of Stereolithography; a light-emitting device a) (laser or DLP) selectively illuminate the transparent bottom c) of a tank b) filled with a liquid photo-polymerizing resin; the solidified resin d) is progressively dragged up by a lifting platform Other methods cure liquid materials using different sophisticated technologies, such as stereolithography.
Photopolymerization is primarily used in stereolithography to produce a solid part from a liquid. Inkjet printer systems like the Objet PolyJet system spray photopolymer materials onto a build tray in ultra-thin layers (between 16 and 30 µm) until the part is completed.
Each photopolymer layer is cured with UV light after it is jetted, producing fully cured models that can be handled and used immediately, without post-curing. Ultra-small features can be made with the 3D micro-fabrication technique used in multiphoton photopolymerisation. Due to the nonlinear nature of photo excitation, the gel is cured to a solid only in the places where the laser was focused while the remaining gel is then washed away.
Feature sizes of under 100 nm are easily produced, as well as complex structures with moving and interlocked parts.70 Yet another approach uses a synthetic resin that is solidified using LEDs.71In Mask-image-projection-based stereolithography, a 3D digital model is sliced by a set of horizontal planes. Each slice is converted into a two-dimensional mask image. The mask image is then projected onto a photocurable liquid resin surface and light is projected onto the resin to cure it in the shape of the layer.72 Continuous liquid interface production begins with a pool of liquid photopolymer resin.
Part of the pool bottom is transparent to ultraviolet light (the “window”), which causes the resin to solidify. The object rises slowly enough to allow resin to flow under and maintain contact with the bottom of the object.73 In powder-fed directed-energy deposition, a high-power laser is used to melt metal powder supplied to the focus of the laser beam.
The powder fed directed energy process is similar to Selective Laser Sintering, but the metal powder is applied only where material is being added to the part at that moment.7475As of December 2017, additive manufacturing systems were on the market that ranged from $99 to $500,000 in price and were employed in industries including aerospace, architecture, automotive, defense, and medical replacements, among many others. For example, General Electric uses high-end 3D Printers to build parts for turbines.
Many of these systems are used for rapid prototyping, before mass production methods are employed. Higher education has proven to be a major buyer of desktop and professional 3D printers which industry experts generally view as a positive indicator.77 Libraries around the world have also become locations to house smaller 3D printers for educational and community access.
Several projects and companies are making efforts to develop affordable 3D printers for home desktop use. Much of this work has been driven by and targeted at DIY/Maker/enthusiast/early adopter communities, with additional ties to the academic and hacker communities.
Computed axial lithography is a method for 3D printing based on computerised tomography scans to create prints in photo-curable resin. It was developed by a collaboration between the University of California, Berkeley with Lawrence Livermore National Laboratory.
Unlike other methods of 3D printing it does not build models through depositing layers of material like fused deposition modelling and stereolithography, instead it creates objects using a series of 2D images projected onto a cylinder of resin.8082 It is notable for its ability to build an object much more quickly than other methods using resins and the ability to embed objects within the prints.
Liquid additive manufacturing (LAM) is a 3D printing technique which deposits a liquid or high viscose material (e.g. Liquid Silicone Rubber) onto a build surface to create an object which then is vulcanised using heat to harden the object.838485 The process was originally created by Adrian Bowyer and was then built upon by German RepRap.838687
Applications
Main article: Applications of 3D printing The Audi RSQ was made with rapid prototyping industrial KUKA robots. A 3D selfie in 1:20 scale printed using gypsum-based printing A 3D printed jet engine model 3D printed enamelled pottery 3D printed sculpture of an Egyptian Pharaoh shown at Threeding
In the current scenario, 3D printing or Additive Manufacturing has been used in manufacturing, medical, industry and sociocultural sectors which facilitate 3D printing or Additive Manufacturing to become successful commercial technology.88 More recently, 3D printing has also been used in the humanitarian and development sector to produce a range of medical items, prosthetics, spares and repairs.
The earliest application of additive manufacturing was on the toolroom end of the manufacturing spectrum. For example, rapid prototyping was one of the earliest additive variants, and its mission was to reduce the lead time and cost of developing prototypes of new parts and devices, which was earlier only done with subtractive toolroom methods such as CNC milling, turning, and precision grinding.
In the 2010s, additive manufacturing entered production to a much greater extent.Additive manufacturing of food is being developed by squeezing out food, layer by layer, into three-dimensional objects.
A large variety of foods are appropriate candidates, such as chocolate and candy, and flat foods such as crackers, pasta,91 and pizza.9293 NASA is looking into the technology in order to create 3D printed food to limit food waste and to make food that are designed to fit an astronaut’s dietary needs.
In 2018, Italian bioengineer Giuseppe Scionti developed a technology allowing to generate fibrous plant-based meat analogues using a custom 3D bioprinter, mimicking meat texture and nutritional values.
3D printing has entered the world of clothing, with fashion designers experimenting with 3D-printed bikinis, shoes, and dresses.97 In commercial production Nike is using 3D printing to prototype and manufacture the 2012 Vapor Laser Talon football shoe for players of American football, and New Balance is 3D manufacturing custom-fit shoes for athletes.
3D printing has come to the point where companies are printing consumer grade eyewear with on-demand custom fit and styling (although they cannot print the lenses). On-demand customization of glasses is possible with rapid prototyping.
Vanessa Friedman, fashion director and chief fashion critic at The New York Times, says 3D printing will have a significant value for fashion companies down the road, especially if it transforms into a print-it-yourself tool for shoppers.
“There’s real sense that this is not going to happen anytime soon,” she says, “but it will happen, and it will create dramatic change in how we think both about intellectual property and how things are in the supply chain.” She adds: “Certainly some of the fabrications that brands can use will be dramatically changed by technology.
In cars, trucks, and aircraft, Additive Manufacturing is beginning to transform both (1) unibody and fuselage design and production and (2) powertrain design and production. For example:
In early 2014, Swedish supercar manufacturer Koenigsegg announced the One:1, a supercar that utilizes many components that were 3D printed.101 Urbee is the name of the first car in the world car mounted using the technology 3D printing (its bodywork and car windows were “printed”).
In 2014, Local Motors debuted Strati, a functioning vehicle that was entirely 3D Printed using ABS plastic and carbon fiber, except the powertrain.105 In May 2015 Airbus announced that its new Airbus A350 XWB included over 1000 components manufactured by 3D printing.106
In 2015, a Royal Air Force Eurofighter Typhoon fighter jet flew with printed parts. The United States Air Force has begun to work with 3D printers, and the Israeli Air Force has also purchased a 3D printer to print spare parts.107
In 2017, GE Aviation revealed that it had used design for additive manufacturing to create a helicopter engine with 16 parts instead of 900, with great potential impact on reducing the complexity of supply chains.108
AM’s impact on firearms involves two dimensions: new manufacturing methods for established companies, and new possibilities for the making of do-it-yourself firearms. In 2012, the US-based group Defense Distributed disclosed plans to design a working plastic 3D printed firearm “that could be downloaded and reproduced by anybody with a 3D printer.”
After Defense Distributed released their plans, questions were raised regarding the effects that 3D printing and widespread consumer-level CNC machining111112 may have on gun control effectiveness.
Surgical uses of 3D printing-centric therapies have a history beginning in the mid-1990s with anatomical modeling for bony reconstructive surgery planning. Patient-matched implants were a natural extension of this work, leading to truly personalized implants that fit one unique individual.
Virtual planning of surgery and guidance using 3D printed, personalized instruments have been applied to many areas of surgery including total joint replacement and craniomaxillofacial reconstruction with great success.
One example of this is the bioresorbable trachial splint to treat newborns with tracheobronchomalacia developed at the University of Michigan. The use of additive manufacturing for serialized production of orthopedic implants (metals) is also increasing due to the ability to efficiently create porous surface structures that facilitate osseointegration.
The hearing aid and dental industries are expected to be the biggest area of future development using the custom 3D printing technology.120In March 2014, surgeons in Swansea used 3D printed parts to rebuild the face of a motorcyclist who had been seriously injured in a road accident.
In May 2018, 3D printing has been used for the kidney transplant to save a three-year-old boy.122 As of 2012, 3D bio-printing technology has been studied by biotechnology firms and academia for possible use in tissue engineering applications in which organs and body parts are built using inkjet printing techniques.
In this process, layers of living cells are deposited onto a gel medium or sugar matrix and slowly built up to form three-dimensional structures including vascular systems.123 Recently, a heart-on-chip has been created which matches properties of cells.124In 3D printing, computer-simulated microstructures are commonly used to fabricate objects with spatially varying properties.
This is achieved by dividing the volume of the desired object into smaller subcells using computer aided simulation tools and then filling these cells with appropriate microstructures during fabrication. Several different candidate structures with similar behaviours are checked against each other and the object is fabricated when an optimal set of structures are found.
Advanced topology optimization methods are used to ensure the compatibility of structures in adjacent cells. This flexible approach to 3D fabrication is widely used across various disciplines from biomedical sciences where they are used to create complex bone structures125 and human tissue126 to robotics where they are used in the creation of soft robots with movable parts.
3D printing has also been employed by researchers in the pharmaceutical field. During the last few years there’s been a surge in academic interest regarding drug delivery with the aid of AM techniques. This technology offers a unique way for materials to be utilized in novel formulations. One of the major advantages of 3D printing, is the personalization of the dosage form that can be achieved, thus, targeting the patient’s specific needs129.
In the not-so-distant future, 3D printers are expected to reach hospitals and pharmacies in order to provide on demand production of personalized formulations according to the patients’ needs130.
In 2018, 3D printing technology was used for the first time to create a matrix for cell immobilization in fermentation. Propionic acid production by Propionibacterium acidipropionici immobilized on 3D-printed nylon beads was chosen as a model study. It was shown that those 3D-printed beads were capable of promoting high density cell attachment and propionic acid production, which could be adapted to other fermentation bioprocesses.
In 2005, academic journals had begun to report on the possible artistic applications of 3D printing technology.132 As of 2017, domestic 3D printing was reaching a consumer audience beyond hobbyists and enthusiasts. Off the shelf machines were increasingly capable of producing practical household applications, for example, ornamental objects. Some practical examples include a working clock133 and gears printed for home woodworking machines among other purposes.
Web sites associated with home 3D printing tended to include backscratchers, coat hooks, door knobs, etc.1353D printing, and open source 3D printers in particular, are the latest technology making inroads into the classroom.136137138139 Some authors have claimed that 3D printers offer an unprecedented “revolution” in STEM education.140141 The evidence for such claims comes from both the low-cost ability for rapid prototyping in the classroom by students, but also the fabrication of low-cost high-quality scientific equipment from open hardware designs forming open-source labs.
Future applications for 3D printing might include creating open-source scientific equipment.142143In the last several years 3D printing has been intensively used by in the cultural heritage field for preservation, restoration and dissemination purposes.144 Many Europeans and North American Museums have purchased 3D printers and actively recreate missing pieces of their relics.145 The Metropolitan Museum of Art and the British Museum have started using their 3D printers to create museum souvenirs that are available in the museum shops.146 Other museums, like the National Museum of Military History and Varna Historical Museum, have gone further and sell through the online platform Threeding digital models of their artifacts, created using Artec 3D scanners, in 3D printing friendly file format, which everyone can 3D print at home.
3D printed soft actuators is a growing application of 3D printing technology which has found its place in the 3D printing applications. These soft actuators are being developed to deal with soft structures and organs especially in biomedical sectors and where the interaction between human and robot is inevitable. The majority of the existing soft actuators are fabricated by conventional methods that require manual fabrication of devices, post processing/assembly, and lengthy iterations until maturity of the fabrication is achieved. Instead of the tedious and time-consuming aspects of the current fabrication processes, researchers are exploring an appropriate manufacturing approach for effective fabrication of soft actuators.
Thus, 3D printed soft actuators are introduced to revolutionise the design and fabrication of soft actuators with custom geometrical, functional, and control properties in a faster and inexpensive approach. They also enable incorporation of all actuator components into a single structure eliminating the need to use external joints, adhesives, and fasteners. Circuit board manufacturing involves multiple steps which include imaging, drilling, plating, soldermask coating, nomenclature printing and surface finishes. These steps include many chemicals such as harsh solvents and acids. 3D printing circuit boards remove the need for many of these steps while still producing complex designs.
Polymer ink is used to create the layers of the build while silver polymer is used for creating the traces and holes used to allow electricity to flow.149 Current circuit board manufacturing can be a tedious process depending on the design. Specified materials are gathered and sent into inner layer processing where images are printed, developed and etched. The etches cores are typically punched to add lamination tooling. The cores are then prepared for lamination. The stack-up, the buildup of a circuit board, is built and sent into lamination where the layers are bonded. The boards are then measured and drilled. Many steps may differ from this stage however for simple designs, the material goes through a plating process to plate the holes and surface. The outer image is then printed, developed and etched. After the image is defined, the material must get coated with soldermask for later soldering. Nomenclature is then added so components can be identified later.
Then the surface finish is added. The boards are routed out of panel form into their singular or array form and then electrically tested. Aside from the paperwork which must be completed which proves the boards meet specifications, the boards are then packed and shipped. The benefits of 3D printing would be that the final outline is defined from the beginning, no imaging, punching or lamination is required and electrical connections are made with the silver polymer which eliminates drilling and plating. The final paperwork would also be greatly reduced due to the lack of materials required to build the circuit board. Complex designs which may takes weeks to complete through normal processing can be 3D printed, greatly reducing manufacturing time.
Legal aspects
Intellectual property
See also: Free hardware
3D printing has existed for decades within certain manufacturing industries where many legal regimes, including patents, industrial design rights, copyrights, and trademarks may apply. However, there is not much jurisprudence to say how these laws will apply if 3D printers become mainstream and individuals or hobbyist communities begin manufacturing items for personal use, for non-profit distribution, or for sale.Any of the mentioned legal regimes may prohibit the distribution of the designs used in 3D printing, or the distribution or sale of the printed item. To be allowed to do these things, where an active intellectual property was involved, a person would have to contact the owner and ask for a licence, which may come with conditions and a price. However, many patent, design and copyright laws contain a standard limitation or exception for ‘private’, ‘non-commercial’ use of inventions, designs or works of art protected under intellectual property (IP). That standard limitation or exception may leave such private, non-commercial uses outside the scope of IP rights.Patents cover inventions including processes, machines, manufacturing, and compositions of matter and have a finite duration which varies between countries, but generally 20 years from the date of application. Therefore, if a type of wheel is patented, printing, using, or selling such a wheel could be an infringement of the patent.150Copyright covers an expression151 in a tangible, fixed medium and often lasts for the life of the author plus 70 years thereafter.152 If someone makes a statue, they may have a copyright mark on the appearance of that statue, so if someone sees that statue, they cannot then distribute designs to print an identical or similar statue.When a feature has both artistic (copyrightable) and functional (patentable) merits, when the question has appeared in US court, the courts have often held the feature is not copyrightable unless it can be separated from the functional aspects of the item.152 In other countries the law and the courts may apply a different approach allowing, for example, the design of a useful device to be registered (as a whole) as an industrial design on the understanding that, in case of unauthorized copying, only the non-functional features may be claimed under design law whereas any technical features could only be claimed if covered by a valid patent.
Gun legislation and administration
Main article: 3D printed firearms
The US Department of Homeland Security and the Joint Regional Intelligence Center released a memo stating that “significant advances in three-dimensional (3D) printing capabilities, availability of free digital 3D printable files for firearms components, and difficulty regulating file sharing may present public safety risks from unqualified gun seekers who obtain or manufacture 3D printed guns” and that “proposed legislation to ban 3D printing of weapons may deter, but cannot completely prevent, their production. Even if the practice is prohibited by new legislation, online distribution of these 3D printable files will be as difficult to control as any other illegally traded music, movie or software files.”153 Currently, it is not prohibited by law to manufacture firearms for personal use in the United States, as long as the firearm is not produced with the intent to be sold or transferred, and meets a few basic requirements. A license is required to manufacture firearms for sale or distribution. The law prohibits a person from assembling a non–sporting semiautomatic rifle or shotgun from 10 or more imported parts, as well as firearms that cannot be detected by metal detectors or x–ray machines. In addition, the making of an NFA firearm requires a tax payment and advance approval by ATF.154Attempting to restrict the distribution of gun plans via the Internet has been likened to the futility of preventing the widespread distribution of DeCSS, which enabled DVD ripping.155156157158 After the US government had Defense Distributed take down the plans, they were still widely available via the Pirate Bay and other file sharing sites.159 Downloads of the plans from the UK, Germany, Spain, and Brazil were heavy.160161 Some US legislators have proposed regulations on 3D printers to prevent them from being used for printing guns.162163 3D printing advocates have suggested that such regulations would be futile, could cripple the 3D printing industry, and could infringe on free speech rights, with early pioneer of 3D printing Professor Hod Lipson suggesting that gunpowder could be controlled instead.164165166167168169Internationally, where gun controls are generally stricter than in the United States, some commentators have said the impact may be more strongly felt since alternative firearms are not as easily obtainable.170 Officials in the United Kingdom have noted that producing a 3D printed gun would be illegal under their gun control laws.171 Europol stated that criminals have access to other sources of weapons but noted that as technology improves, the risks of an effect would increase.172173
Aerospace regulation
In the United States, the FAA has anticipated a desire to use additive manufacturing techniques and has been considering how best to regulate this process.174 The FAA has jurisdiction over such fabrication because all aircraft parts must be made under FAA production approval or under other FAA regulatory categories.175 In December 2016, the FAA approved the production of a 3D printed fuel nozzle for the GE LEAP engine.176 Aviation attorney Jason Dickstein has suggested that additive manufacturing is merely a production method, and should be regulated like any other production method.177178 He has suggested that the FAA’s focus should be on guidance to explain compliance, rather than on changing the existing rules, and that existing regulations and guidance permit a company “to develop a robust quality system that adequately reflects regulatory needs for quality assurance.”177
Health and safety It has been suggested that this section be split out into another article titled Health and safety hazards of 3D printing. (Discuss) (October 2018)
A video on research done on printer emissions
See also: Health and safety hazards of nanomaterials
Research on the health and safety concerns of 3D printing is new and in development due to the recent proliferation of 3D printing devices. In 2017 the European Agency for Safety and Health at Work has published a discussion paper on the processes and materials involved in 3D printing, potential implications of this technology for occupational safety and health and avenues for controlling potential hazards.179
Hazards
Emissions
Emissions from fused filament printers can include a large number of ultrafine particles and volatile organic compounds (VOCs).180181182 The toxicity from emissions varies by source material due to differences in size, chemical properties, and quantity of emitted particles.180 Excessive exposure to VOCs can lead to irritation of the eyes, nose, and throat, headache, loss of coordination, and nausea and some of the chemical emissions of fused filament printers have also been linked to asthma.180183 Based on animal studies, carbon nanotubes and carbon nanofibers sometimes used in fused filament printing can cause pulmonary effects including inflammation, granulomas, and pulmonary fibrosis when at the nanoparticle size.184 A National Institute for Occupational Safety and Health (NIOSH) study noted particle emissions from a fused filament peaked a few minutes after printing started and returned to baseline levels 100 minutes after printing ended.180 Workers may also inadvertently transport materials outside the workplace on their shoes, garments, and body, which may pose hazards for other members of the public.185Carbon nanoparticle emissions and processes using powder metals are highly combustible and raise the risk of dust explosions.186 At least one case of severe injury was noted from an explosion involved in metal powders used for fused filament printing.187
Other
Additional hazards include burns from hot surfaces such as lamps and print head blocks, exposure to laser or ultraviolet radiation, electrical shock, mechanical injury from being struck by moving parts, and noise and ergonomic hazards.188189 Other concerns involve gas and material exposures, in particular nanomaterials, material handling, static electricity, moving parts and pressures.190Hazards to health and safety also exist from post-processing activities done to finish parts after they have been printed. These post-processing activities can include chemical baths, sanding, polishing, or vapor exposure to refine surface finish, as well as general subtractive manufacturing techniques such as drilling, milling, or turning to modify the printed geometry.191 Any technique that removes material from the printed part has the potential to generate particles that can be inhaled or cause eye injury if proper personal protective equipment is not used, such as respirators or safety glasses. Caustic baths are often used to dissolve support material used by some 3D printers that allows them to print more complex shapes. These baths require personal protective equipment to prevent injury to exposed skin.189Since 3-D imaging creates items by fusing materials together, there runs the risk of layer separation in some devices made using 3-D Imaging. For example, in January 2013, the US medical device company, DePuy, recalled their knee and hip replacement systems. The devices were made from layers of metal, and shavings had come loose – potentially harming the patient.192
Hazard controls 3D printers with the manufacturer-provided plastic covers and doors installed, which are examples of engineering controls
Hazard controls include using manufacturer-supplied covers and full enclosures, using proper ventilation, keeping workers away from the printer, using respirators, turning off the printer if it jammed, and using lower emission printers and filaments. Personal protective equipment has been found to be the least desirable control method with a recommendation that it only be used to add further protection in combination with approved emissions protection.180
Health regulation
Although no occupational exposure limits specific to 3D printer emissions exist, certain source materials used in 3D printing, such as carbon nanofiber and carbon nanotubes, have established occupational exposure limits at the nanoparticle size.180193As of March 2018, the US Government has set 3D printer emission standards for only a limited number of compounds. Furthermore, the few established standards address factory conditions, not home or other environments in which the printers are likely to be used.194
Impact
Additive manufacturing, starting with today’s infancy period, requires manufacturing firms to be flexible, ever-improving users of all available technologies to remain competitive. Advocates of additive manufacturing also predict that this arc of technological development will counter globalization, as end users will do much of their own manufacturing rather than engage in trade to buy products from other people and corporations.[10] The real integration of the newer additive technologies into commercial production, however, is more a matter of complementing traditional subtractive methods rather than displacing them entirely.[195]The futurologist Jeremy Rifkin[196] claimed that 3D printing signals the beginning of a third industrial revolution,[197] succeeding the production line assembly that dominated manufacturing starting in the late 19th century.
Social change Street sign in Windhoek, Namibia, advertising 3D printing, July 2018
Since the 1950s, a number of writers and social commentators have speculated in some depth about the social and cultural changes that might result from the advent of commercially affordable additive manufacturing technology.[198] In recent years, 3D printing is creating significant impact in the humanitarian and development sector. Its potential to facilitate distributed manufacturing is resulting in supply chain and logistics benefits, by reducing the need for transportation, warehousing and wastage. Furthermore, social and economic development is being advanced through the creation of local production economies.[89]Others have suggested that as more and more 3D printers start to enter people’s homes, the conventional relationship between the home and the workplace might get further eroded.[199] Likewise, it has also been suggested that, as it becomes easier for businesses to transmit designs for new objects around the globe, so the need for high-speed freight services might also become less.[200] Finally, given the ease with which certain objects can now be replicated, it remains to be seen whether changes will be made to current copyright legislation so as to protect intellectual property rights with the new technology widely available.As 3D printers became more accessible to consumers, online social platforms have developed to support the community.[201] This includes websites that allow users to access information such as how to build a 3D printer, as well as social forums that discuss how to improve 3D print quality and discuss 3D printing news, as well as social media websites that are dedicated to share 3D models.[202][203][204] RepRap is a wiki based website that was created to hold all information on 3d printing, and has developed into a community that aims to bring 3D printing to everyone. Furthermore, there are other sites such as Pinshape, Thingiverse and MyMiniFactory, which were created initially to allow users to post 3D files for anyone to print, allowing for decreased transaction cost of sharing 3D files. These websites have allowed greater social interaction between users, creating communities dedicated to 3D printing.Some call attention to the conjunction of Commons-based peer production with 3D printing and other low-cost manufacturing techniques.[205][206][207] The self-reinforced fantasy of a system of eternal growth can be overcome with the development of economies of scope, and here, society can play an important role contributing to the raising of the whole productive structure to a higher plateau of more sustainable and customized productivity.[205] Further, it is true that many issues, problems, and threats arise due to the democratization of the means of production, and especially regarding the physical ones.[205] For instance, the recyclability of advanced nanomaterials is still questioned; weapons manufacturing could become easier; not to mention the implications for counterfeiting[208] and on intellectual property.[209] It might be maintained that in contrast to the industrial paradigm whose competitive dynamics were about economies of scale, Commons-based peer production 3D printing could develop economies of scope. While the advantages of scale rest on cheap global transportation, the economies of scope share infrastructure costs (intangible and tangible productive resources), taking advantage of the capabilities of the fabrication tools.[205] And following Neil Gershenfeld[210] in that “some of the least developed parts of the world need some of the most advanced technologies,” Commons-based peer production and 3D printing may offer the necessary tools for thinking globally but acting locally in response to certain needs.Larry Summers wrote about the “devastating consequences” of 3D printing and other technologies (robots, artificial intelligence, etc.) for those who perform routine tasks. In his view, “already there are more American men on disability insurance than doing production work in manufacturing. And the trends are all in the wrong direction, particularly for the less skilled, as the capacity of capital embodying artificial intelligence to replace white-collar as well as blue-collar work will increase rapidly in the years ahead.” Summers recommends more vigorous cooperative efforts to address the “myriad devices” (e.g., tax havens, bank secrecy, money laundering, and regulatory arbitrage) enabling the holders of great wealth to “a paying” income and estate taxes, and to make it more difficult to accumulate great fortunes without requiring “great social contributions” in return, including: more vigorous enforcement of anti-monopoly laws, reductions in “excessive” protection for intellectual property, greater encouragement of profit-sharing schemes that may benefit workers and give them a stake in wealth accumulation, strengthening of collective bargaining arrangements, improvements in corporate governance, strengthening of financial regulation to eliminate subsidies to financial activity, easing of land-use restrictions that may cause the real estate of the rich to keep rising in value, better training for young people and retraining for displaced workers, and increased public and private investment in infrastructure development—e.g., in energy production and transportation.[211]Michael Spence wrote that “Now comes a … powerful, wave of digital technology that is replacing labor in increasingly complex tasks. This process of labor substitution and disintermediation has been underway for some time in service sectors—think of ATMs, online banking, enterprise resource planning, customer relationship management, mobile payment systems, and much more. This revolution is spreading to the production of goods, where robots and 3D printing are displacing labor.” In his view, the vast majority of the cost of digital technologies comes at the start, in the design of hardware (e.g. 3D printers) and, more important, in creating the software that enables machines to carry out various tasks. “Once this is achieved, the marginal cost of the hardware is relatively low (and declines as scale rises), and the marginal cost of replicating the software is essentially zero. With a huge potential global market to amortize the upfront fixed costs of design and testing, the incentives to invest [in digital technologies] are compelling.”[212]Spence believes that, unlike prior digital technologies, which drove firms to deploy underutilized pools of valuable labor around the world, the motivating force in the current wave of digital technologies “is cost reduction via the replacement of labor.” For example, as the cost of 3D printing technology declines, it is “easy to imagine” that production may become “extremely” local and customized. Moreover, production may occur in response to actual demand, not anticipated or forecast demand. Spence believes that labor, no matter how inexpensive, will become a less important asset for growth and employment expansion, with labor-intensive, process-oriented manufacturing becoming less effective, and that re-localization will appear in both developed and developing countries. In his view, production will not disappear, but it will be less labor-intensive, and all countries will eventually need to rebuild their growth models around digital technologies and the human capital supporting their deployment and expansion. Spence writes that “the world we are entering is one in which the most powerful global flows will be ideas and digital capital, not goods, services, and traditional capital. Adapting to this will require shifts in mindsets, policies, investments (especially in human capital), and quite possibly models of employment and distribution.”[212]Naomi Wu regards the usage of 3D printing in the Chinese classroom (where rote memorization is standard) to teach design principles and creativity as the most exciting recent development of the technology, and more generally regards 3D printing as being the next desktop publishing revolution.[213]
Environmental change
The growth of additive manufacturing could have a large impact on the environment. As opposed to traditional manufacturing, for instance, in which pieces are cut from larger blocks of material, additive manufacturing creates products layer-by-layer and prints only relevant parts, wasting much less material and thus wasting less energy in producing the raw materials needed.[214] By making only the bare structural necessities of products, additive manufacturing also could make a profound contribution to lightweighting, reducing the energy consumption and greenhouse gas emissions of vehicles and other forms of transportation.[215] A case study on an airplane component made using additive manufacturing, for example, found that the component’s use saves 63% of relevant energy and carbon dioxide emissions over the course of the product’s lifetime.[216] In addition, previous life-cycle assessment of additive manufacturing has estimated that adopting the technology could further lower carbon dioxide emissions since 3D printing creates localized production, and products would not need to be transported long distances to reach their final destination.[217]Continuing to adopt additive manufacturing does pose some environmental downsides, however. Despite additive manufacturing reducing waste from the subtractive manufacturing process by up to 90%, the additive manufacturing process creates other forms of waste such as non-recyclable material powders. Additive manufacturing has not yet reached its theoretical material efficiency potential of 97%, but it may get closer as the technology continues to increase productivity.[218]
What is 3D Printing?TweetLinkedInShareReddit3D printing or additive manufacturing is a process of making three dimensional solid objects from a digital file.The creation of a 3D printed object is achieved using additive processes. In an additive process an object is created by laying down successive layers of material until the object is created. Each of these layers can be seen as a thinly sliced horizontal cross-section of the eventual object.3D printing is the opposite of subtractive manufacturing which is cutting out / hollowing out a piece of metal or plastic with for instance a milling machine.3D printing enables you to produce complex shapes using less material than traditional manufacturing methods.
Table of Contents
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How Does 3D Printing Work?It all starts with a 3D model. You create one yourself or download it from a 3D repository. When creating it yourself you can choose to use a 3D scanner, app, haptic device, code or 3D modeling software.3D Modeling SoftwareThere are many different 3D modeling software tools available. Industrial grade software can easily cost thousands a year per license, but there’s also open source software you can get for free.We often recommend beginners to start with Tinkercad. Tinkercad is free and works in your browser, you don’t have to install it on your computer. Tinkercad offers beginner lessons and has a built-in feature to get your 3D model printed via a 3D print service.Now that you have a 3D model, the next step is to prepare the file for your 3D printer. This is called slicing.Slicing: From 3D Model to 3D PrinterSlicing is dividing a 3D model into hundreds or thousands of horizontal layers and is done with slicing software.Some 3D printers have a built-in slicer and let you feed the raw .stl, .obj or even CAD file.When your file is sliced, it’s ready to be fed to your 3D printer. This can be done via USB, SD or internet. Your sliced 3D model is now ready to be 3D printed layer by layer.3D Printing IndustryAdoption of 3D printing has reached critical mass as those who have yet to integrate additive manufacturing somewhere in their supply chain are now part of an ever-shrinking minority. Where 3D printing was only suitable for prototyping and one-off manufacturing in the early stages, it is now rapidly transforming into a production technology.Most of the current demand for 3D printing is industrial in nature. Acumen Research and Consulting forecasts the global 3D printing market to reach $41 billion by 2026.As it evolves, 3D printing technology is destined to transform almost every major industry and change the way we live, work, and play in the future.Examples of 3D Printing3D printing encompasses many forms of technologies and materials as 3D printing is being used in almost all industries you could think of. It’s important to see it as a cluster of diverse industries with a myriad of different applications.A few examples:
– consumer products (eyewear, footwear, design, furniture)
– industrial products (manufacturing tools, prototypes, functional end-use parts)
– dental products
– prosthetics
– architectural scale models & maquettes
– reconstructing fossils
– replicating ancient artefacts
– reconstructing evidence in forensic pathology
– movie props
Testing A Lamborghini With 3D Printed PETG Intake Stack Prototypes
How 3D Printing Is Changing Auto Manufacturing
3D Printing Spare Parts On-Demand
How 3D Printed Sports Equipment Is Changing the Game
3 Ways 3D Printing is Revolutionizing Digital Dentistry
3 Ways The Furniture Industry Benefits from 3D Printing
3D Printing & Embedded Electronics – How AM Enables Smarter Objects
3D Printed Props – How 3D Printing is Used in Film & TV
Testing A Lamborghini With 3D Printed PETG Intake Stack Prototypes
How 3D Printing Is Changing Auto Manufacturing
3D Printing Spare Parts On-Demand
How 3D Printed Sports Equipment Is Changing the Game
3 Ways 3D Printing is Revolutionizing Digital Dentistry
3 Ways The Furniture Industry Benefits from 3D Printing
Rapid Prototyping & Rapid ManufacturingCompanies have used 3D printers in their design process to create prototypes since the late seventies. Using 3D printers for these purposes is called rapid prototyping.Why use 3D Printers for Rapid Prototyping?
In short: it’s fast and relatively cheap. From idea, to 3D model to holding a prototype in your hands is a matter of days instead of weeks. Iterations are easier and cheaper to make and you don’t need expensive molds or tools.Besides rapid prototyping, 3D printing is also used for rapid manufacturing. Rapid manufacturing is a new method of manufacturing where businesses use 3D printers for short run / small batch custom manufacturing.
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AutomotiveCar manufacturers have been utilizing 3D printing for a long time. Automotive companies are printing spare parts, tools, jigs and fixtures but also end-use parts. 3D printing has enabled on-demand manufacturing which has lead to lower stock levels and has shortened design and production cycles.Automotive enthusiasts all over the world are using 3D printed parts to restore old cars. One such example is when Australian engineers printed parts to bring a Delage Type-C back to life. In doing so, they had to print parts that were out of production for decades.
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AviationThe aviation industry uses 3D printing in many different ways. The following example marks a significant 3D printing manufacturing milestone: GE Aviation has 3D printed 30,000 Cobalt-chrome fuel nozzles for its LEAP aircraft engines. They achieved that milestone in October of 2018, and considering that they produce 600 per week on forty 3D printers, it’s likely much higher than that now.Around twenty individual parts that previously had to be welded together were consolidated into one 3D printed component that weighs 25% less and is five times stronger. The LEAP engine is the best selling engine in the aviation sector due to its high level of efficiency and GE saves $3 million per aircraft by 3D printing the fuel nozzles, so this single 3D printed part generates hundreds of millions of dollars of financial benefit. GE’s fuel nozzles also made their way into the Boeing 787 Dreamliner, but it’s not the only 3D printed part in the 787. The 33-centimeter-long structural fittings that hold the aft kitchen galley to the airframe are 3D printed by a company called Norsk Titanium. Norsk chose to specialize in titanium because it has a very high strength-to-weight ratio and is rather expensive, meaning the reduction in waste enabled by 3D printing has a more significant financial impact than compared to cheaper metals where the costs of material waste are easier to absorb. Rather than sintering metal powder with a laser like most metal 3D printers, the Norsk Merke 4 uses a plasma arc to melt a metal wire in a process called Rapid Plasma Deposition (a form of Directed Energy Deposition) that can deposit up to 10kg of titanium per hour. A 2kg titanium part would generally require a 30kg block of titanium to machine it from, generating 28kg of waste, but 3D printing the same part requires only 6kg of titanium wire.Boeing has been using 3D printed parts in their airplanes for a long time. Back in 2015 it was estimated that Boeing had more than 20,000 3D printed parts implemented in their airplanes.
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ConstructionIs it possible to print a building? – yes it is. 3D printing is what many believe the future of construction. It’s already possible to print walls, doors, floors and even complete houses.
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Contour CraftingBehrokh Khoshnevis, pioneer of printing with concrete (also known as Contour Crafting), developed a method which leverages the power of additive manufacturing in construction. Contour Crafting essentially uses a robotic device to automate the construction of large structures such as homes. This device prints walls layer-by-layer by extruding concrete. The walls are smoothed as they are built, thanks to a robotic trowel. Consumer ProductsWhen we first started blogging about 3D printing back in 2011, 3D printing wasn’t ready to be used as a production method for larger volumes. Nowadays there are numerous examples of end-use consumer products with 3D printed parts in it.FootwearAdidas’ 4D range has a fully 3D printed midsole and is being printed in large volumes. In 2018 they’ve printed 100,000 midsoles and expect to print even more in 2019.
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The total market of 3D printed footwear is forecasted to reach $5.9 billion by 2029.
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EyewearThe market of 3D printed eyewear is forecasted to reach $3.4 billion by 2028. A rapidly increasing section is that of end-use frames. 3D printing is a particularly suitable production method for eyewear frames because the measurements of an individual are easy to process in the end product.
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But did you know it’s also possible to 3D print lenses? Traditional glass lenses don’t start out thin and light; they’re cut from a much larger block of material called a blank, about 80% of which goes to waste. When we consider how many people wear glasses and how often they need to get a new pair, 80% of those numbers is a lot of waste. On top of that, labs have to keep huge inventories of blanks to meet the custom vision needs of their clients. Finally, however, 3D printing technology has advanced enough to provide high-quality, custom ophthalmic lenses, doing away with the waste and inventory costs of the past. The Luxexcel VisionEngine 3D printer uses a UV-curable acrylate monomer to print two pairs of lenses per hour that require no polishing or post-processing of any kind. The focal areas can also be completely customized so that a certain area of the lens can provide better clarity at a distance while a different area of the lens provides better vision up close.JewelryThere are two ways of creating jewelry via 3D printing. Directly print an object via Metal Powder Bed Fusion or you can print a tool (cast or mold) to create the end product via casting.HealthcareIt’s not uncommon these days to see headlines about 3D printed implants. Often, those cases are experimental, which can make it seem like 3D printing is still a fringe technology in the medical and healthcare sectors, but that’s not the case. Over the last decade, more than 100,000 hip replacements have been 3D printed on just Arcam (now a part of GE Additive) machines; more have been printed on other systems.The Delta-TT Cup designed by Dr. Guido Grappiolo and LimaCorporate is made of Trabecular Titanium, which is characterized by a regular, three-dimensional, hexagonal cell structure that imitates trabecular bone morphology. The trabecular structure increases the biocompatibility of the titanium by encouraging bone growth into the implant. Some of the first Delta-TT implants are still running strong over a decade later.Another 3D printed healthcare device that does a good job of being undetectable is the hearing aid. Nearly every hearing aid in the last 17 years has been 3D printed thanks to a collaboration between Materialise and Phonak, a hearing aid manufacturer. They developed Rapid Shell Modeling (RSM) in 2001. Prior to RSM, making one hearing aid required nine laborious steps involving hand sculpting and mold making, and the results were often ill-fitting. With RSM, a technician uses silicone to take an impression of the ear canal, that impression is 3D scanned, and after some minor tweaking the model is 3D printed with an SLA (stereolithography) vat photopolymerization machine. The electronics are added and then it’s shipped to the user. Using this process, hundreds of thousands of hearing aids are 3D printed each year, each one customized just for its user. RSM delivers a better fit while reducing cost and requiring significantly less time to fabricate than the old manual way of making hearing aids.DentalA very similar process to RSM is also taking over in the dental industry, where molds for clear aligners like are possibly the most 3D printed objects in the world. Currently, the molds are 3D printed with both resin and powder based processes, but also with the aid of material jetting.Crowns and dentures are already directly 3D printed, along with surgical guides. EnvisionTec is the most popular brand of 3D printers among dental technicians, but Stratasys and Carbon also cater to the industry with dental resins.
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Bio-printingAs of the early two-thousands 3D printing technology has been studied by biotech firms and academia for possible use in tissue engineering applications where organs and body parts are built using inkjet techniques. Layers of living cells are deposited onto a gel medium and slowly built up to form three dimensional structures. We refer to this field of research with the term: bio-printing.
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AerospaceIf you want to see 3D printing applied in the wildest ways imaginable, look no further than the aerospace industry. There is a vast amount of both real-life examples as well as futuristic concepts worth mentioning.For instance UK start-up Orbex whom have built the world’s largest 3D printed rocket engine. The engine is unique in that it’s the first one printed entirely as a single piece without any joins.
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In regards to futuristic concepts, researchers at the University of Ottawa presented the idea of self-replicating 3D printers that process lunar soil. These printers, while still a concept, could lead to exponentially decreasing the amount of materials and equipment necessary for a lunar mission.
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FoodAdditive manufacturing invaded the food industry long time ago. Restaurants like Food Ink and Melisse use this as a unique selling point to attract customers from across the world.
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EducationEducators and students have long been using 3D printers in the classroom. 3D printing enables students to materialize their ideas in a fast and affordable way.Programs such as Create Education Project enable schools to integrate additive manufacturing technologies into their curriculum for essentially no cost. The project lends a 3D printer to schools in exchange for either a blog post about the teacher’s experience of using it or a sample of their lesson plan for class. This allows the company to show what 3D printers can do in an educational environment.
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3D Printing in Education
While additive manufacturing-specific degrees are a fairly new advent, universities have long been using 3D printers in other disciplines. There are many educational courses one can take to engage with 3D printing. Universities offer courses on things that are adjacent to 3D printing like CAD and 3D design, which can be applied to 3D printing at a certain stage.In terms of prototyping, many university programs are turning to printers. There are specialisations in additive manufacturing one can attain through architecture or industrial design degrees. Printed prototypes are also very common in the arts, animation and fashion studies as well.Research labs in a diverse range of vocations are employing 3D printing for functional use. While most studies are still employing the printers for models, medical and aerospace engineers are putting them to use in creating new technologies. Medical labs are producing all sorts of bio-printers and designs for prosthetics. Engineers are, similarly, incorporating printing into designs automobiles and airplanes.Learn How to 3D PrintThe Self-Taught WayGetting started with 3D printing means asking yourself what you would like to learn first. Are you interested in the hardware, or do you want to focus on the end result – creating objects? Answering this question could lead you to the decision if you should buy a 3D printer or outsource the actual printing to a 3D print service.Which 3D Printer Is Right for You?We recommend that you take your time to investigate which 3D printer is right for you. For instance, the range of printable materials can differ quite a bit between a resin-based printer or a filament-based machine. Or maybe you don’t want to spend too much time on tinkering and want to focus on product development. Those are just a few things to keep in mind when you research what’s best for you. Below you’ll find a few links that can help you in the decision making process.
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Workshops & Online CoursesThe educational environment is not only limited to institutional and schools. There are a great deal of other ways one can learn about additive manufacturing. One of the increasingly popular ones is to do it online. To supplement online studies, many companies offer discount deals for 3D printers and related tech.
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Serious About Pursuing a 3D Printing Career But Don’t Know Where to Start?
You can also teach yourself for free by watching YouTube videos. Many YouTubers and online tutors make a living off of assembling 3D printers and creating free tutorials.Types of 3D Printing Technologies and ProcessesThere are several ways to 3D print. All these technologies are additive, differing mainly in the way layers are built to create an object.Some methods use melting or softening material to extrude layers. Others cure a photo-reactive resin with a UV laser (or another similar light source) layer by layer.To be more precise: since 2010, the American Society for Testing and Materials (ASTM) group “ASTM F42 – Additive Manufacturing”, developed a set of standards that classify the Additive Manufacturing processes into 7 categories according to Standard Terminology for Additive Manufacturing Technologies. These seven processes are:
Vat Photopolymerisation
Stereolithography (SLA)
Digital Light Processing (DLP)
Continuous Liquid Interface Production (CLIP)
Material Jetting
Binder Jetting
Material Extrusion
Fused Deposition Modeling (FDM)
Fused Filament Fabrication (FFF)
Powder Bed Fusion
Multi Jet Fusion (MJF)
Selective Laser Sintering (SLS)
Direct Metal Laser Sintering (DMLS)
Sheet Lamination
Directed Energy Deposition
Below you’ll find a short explanation of all of seven processes for 3D printing:Vat PhotopolymerisationA 3D printer based on the Vat Photopolymerisation method has a container filled with photopolymer resin which is then hardened with a UV light source.
Vat photopolymerisation schematics. Image source: lboro.ac.ukStereolithography (SLA)The most commonly used technology in this processes is Stereolithography (SLA). This technology employs a vat of liquid ultraviolet curable photopolymer resin and an ultraviolet laser to build the object’s layers one at a time. For each layer, the laser beam traces a cross-section of the part pattern on the surface of the liquid resin. Exposure to the ultraviolet laser light cures and solidifies the pattern traced on the resin and joins it to the layer below.After the pattern has been traced, the SLA’s elevator platform descends by a distance equal to the thickness of a single layer, typically 0.05 mm to 0.15 mm (0.002″ to 0.006″). Then, a resin-filled blade sweeps across the cross section of the part, re-coating it with fresh material. On this new liquid surface, the subsequent layer pattern is traced, joining the previous layer. The complete three dimensional object is formed by this project. Stereolithography requires the use of supporting structures which serve to attach the part to the elevator platform and to hold the object because it floats in the basin filled with liquid resin. These are removed manually after the object is finished.This technique was invented in 1986 by Charles Hull, who also at the time founded the company, 3D Systems.Digital Light Processing (DLP)DLP or Digital Light Processing refers to a method of printing that makes use of light and photosensitive polymers. While it is very similar to stereolithography, the key difference is the light-source. DLP utilises traditional light-sources like arc lamps.In most forms of DLP, each layer of the desired structure is projected onto a vat of liquid resin that is then solidified layer by layer as the buildplate moves up or down. As the process does each layer successively, it is quicker than most forms of 3D printing.Continuous Liquid Interface Production (CLIP)One of the fastest processes using Vat Photopolymerisation is called CLIP, short for Continuous Liquid Interface Production, developed by Carbon.Digital Light SynthesisThe heart of the CLIP process is Digital Light Synthesis technology. In this technology, light from a custom high performance LED light engine projects a sequence of UV images exposing a cross section of the 3D printed part causing the UV curable resin to partially cure in a precisely controlled way. Oxygen passes through the oxygen permeable window creating a thin liquid interface of uncured resin between the window and the printed part known as the dead zone. The dead zone is as thin as ten of microns. Inside the dead zone, oxygen prohibits light from curing the resin situated closest to the window therefore allowing the continuous flow of liquid beneath the printed part. Just above the dead zone the UV projected light upwards causes a cascade like curing of the part.Simply printing with Carbon’s hardware alone does not allow for end use properties with real world applications. Once the light has shaped the part, a second programmable curing process achieves the desired mechanical properties by baking the 3d printed part in a thermal bath or oven. Programmed thermal curing sets the mechanical properties by triggering a secondary chemical reaction causing the material to strengthen achieving the desired final properties.Components printed with Carbon’s technology are on par with injection molded parts. Digital Light Synthesis produces consistent and predictable mechanical properties, creating parts that are truly isotropic.Material JettingIn this process, material is applied in droplets through a small diameter nozzle, similar to the way a common inkjet paper printer works, but it is applied layer-by-layer to a build platform making a 3D object and then hardened by UV light.
Material Jetting schematics. Image source: custompartnet.comBinder JettingWith binder jetting two materials are used: powder base material and a liquid binder. In the build chamber, powder is spread in equal layers and binder is applied through jet nozzles that “glue” the powder particles in the shape of a programmed 3D object. The finished object is “glued together” by binder remains in the container with the powder base material. After the print is finished, the remaining powder is cleaned off and used for 3D printing the next object. This technology was first developed at the Massachusetts Institute of Technology in 1993 and in 1995 Z Corporation obtained an exclusive license.
The following video shows a high-end binder jetting based 3D printer, the ExOne M-Flex. This 3D printer uses metal powder and curing after the binding material is applied. Material ExtrusionThe most commonly used technology in this process is Fused Deposition Modeling (FDM).Fused Deposition Modeling (FDM)
Fused deposition modelling (FDM), a method of rapid prototyping: 1 – nozzle ejecting molten material (plastic), 2 – deposited material (modelled part), 3 – controlled movable table. Image source: Wikipedia, made by user Zureks under CC Attribution-Share Alike 4.0 International license.The FDM technology works using a plastic filament or metal wire which is unwound from a coil and supplying material to an extrusion nozzle which can turn the flow on and off. The nozzle is heated to melt the material and can be moved in both horizontal and vertical directions by a numerically controlled mechanism, directly controlled by a computer-aided manufacturing (CAM) software package. The object is produced by extruding melted material to form layers as the material hardens immediately after extrusion from the nozzle. This technology is most widely used with two plastic 3D printer filament types: ABS (Acrylonitrile Butadiene Styrene) and PLA (Polylactic acid). Though many other materials are available ranging in properties from wood fill to flexible and even conductive materials.FDM was invented by Scott Crump in the late 80’s. After patenting this technology he started the company Stratasys in 1988. The term Fused Deposition Modeling and its abbreviation to FDM are trademarked by Stratasys Inc.Fused Filament Fabrication (FFF)The exactly equivalent term, Fused Filament Fabrication (FFF), was coined by the members of the RepRap project to give a phrase that would be legally unconstrained in its use.There are many different filament 3D Printer configurations. The most popular arrangements are:
Cartesian-XY-Head
Cartesian-XZ-Head
Delta
Core XY
Cartesian-XY-HeadThe first RepRap 3D printer, the Darwin, was based on the Cartesian-XY-head arrangement. The extruder head moves over the X and Y axis and the print bed over the Z. Z axis movement on a 3D printer with the Cartesian-XY-head arrangement is very precise and requires very low accelerations, but the bed needs to be lightweight in order to maintain accuracy.Cartesian-XZ-HeadThe Cartesian-XZ-head arrangement was first introduced by the Mendel which was the second version of the original RepRap – the Darwin. This arrangement differs form Cartesian-XY-head because it moves the print bed over the Y axis and the extruder head over the X axis and the Z axis.DeltaDelta 3D printers owe their name to the way the extruder head is supported by 3 arms in a triangular configuration. The benefit of a Delta arrangement is that the moving parts are lightweight and therefor limit the inertia. This results in faster printing with greater accuracy.Core XYCore XY is a Cartesian arrangement that is rapidly growing in popularity. The movement on the XY gantry depends on a combined effect of X and Y motors. CoreXY is a parallel manipulator system, which means that the motors on a CoreXY system are stationary. Parallel manipulator systems give more rapid acceleration than serial stackup configurations like Cartesian-XZ-head.Powder Bed FusionThe most commonly used technology in this process is Selective Laser Sintering (SLS).Multi Jet Fusion (MJF)Multi Jet Fusion technology is developed by Hewlett Packard. The technology works like this: a sweeping arm deposits a layer of powder material and then another arm equipped with inkjets selectively applies a binder agent over the material. The inkjets also deposit a detailing agent around the binder to ensure precise dimensionality and smooth surfaces. Finally, the layer is exposed to a burst of thermal energy that causes the agents to react; the process is repeated until each layer is complete. The printers can deposit 30 million drops per second to achieve ultra fast and accurate production, and multiple agents can be used on a single part, meaning parts can have different colors and mechanical properties down to the voxel (a 3D pixel).Selective Laser Sintering (SLS)SLS uses a high power laser to fuse small particles of plastic, ceramic or glass powders into a mass that has the desired three dimensional shape. The laser selectively fuses the powdered material by scanning the cross-sections (or layers) generated by the 3D modeling program on the surface of a powder bed. After each cross-section is scanned, the powder bed is lowered by one layer thickness. Then a new layer of material is applied on top and the process is repeated until the object is completed.
SLS system schematic. Image source: Wikipedia from user Materialgeeza under Creative Commons Attribution-Share Alike 3.0 Unported licenseDirect Metal Laser Sintering (DMLS)DMLS is basically the same as SLS, but uses metal powder instead. All unused powder remains as it is and becomes a support structure for the object. Unused powder can be reused for the next print.Due to of increased laser power, DMLS has evolved into a laser melting process. Read more about that and other metal technologies on our metal technologies overview page.
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Metal 3D Printing: An Overview of the Most Common Types
Sheet LaminationSheet lamination involves material in sheets which is bound together with external force. Sheets can be metal, paper or a form of polymer. Metal sheets are welded together by ultrasonic welding in layers and then CNC milled into a proper shape. Paper sheets can be used also, but they are glued by adhesive glue and cut in shape by precise blades.
Simplified model of ultrasonic sheet metal 3D printing. Image source: Wikipedia from user Mmrjf3 shared under Creative Commons Attribution 3.0 Unported license.Directed Energy DepositionThis process is mostly used in the high-tech metal industry and in rapid manufacturing applications. The 3D printing apparatus is usually attached to a multi-axis robotic arm and consists of a nozzle that deposits metal powder or wire on a surface and an energy source (laser, electron beam or plasma arc) that melts it, forming a solid object.
Directed Energy Deposition with metal powder and laser melting. Image source: Merlin projectMaterialsSix types of materials can be used in additive manufacturing: plastics, metals, concrete, ceramics, paper and certain edibles (e.g. chocolate). Materials are often produced in wire feedstock a.k.a. 3D printer filament, powder form or liquid resin. All seven previously described 3D printing techniques, cover the use of these materials, although polymers are most commonly used and some additive techniques lend themselves towards the use of certain materials over others. Read more about which materials you can use for 3D printing on our 3D printer materials page.ServicesIf you are not sure if 3D printing is the right production method for you, and you want to test out the possibilities without purchasing a 3D printer – a 3D print service might be the way to go.
