Did you know that complex plastic or metal parts can be built in a few hours using 3D printers for manufacturing sector, and military purposes?
3D printing is also known as additive manufacturing. This technology uses a digital/CAD design to create three dimensional objects. The manufacturing process generally involves adding up of multiple thinly sliced cross-sections of the object (additive process). This ‘additive manufacturing’ process is an exact opposite of regular/subtractive manufacturing, where parts are created by drilling/boring out excess material from a block of metal or plastic.
In 1967, the first patent for a 3D printer was filed by Wyn Kelly Swainson of Denmark, called “method of producing a three-dimensional figure by holography”. He also filed two relevant patents on 3D printing in 1971 and 1977. In 1981, Dr Hideo Kodama from Nagoya Municipal Industrial Research Institute, Japan developed a rapid prototyping system. This process involves printing (deposition) of a photosensitive resin layer-by-layer to manufacture a part. This resin was hardened or polymerised by UV light. This manufacturing process evolved into today’s SLA (stereolithography). Due to lack of funds, he was unable to file the patent application for this technology within the stipulated time frame. In 1984, three French scientists Jean Claude Andre, Oliver de Witte, and Alain Mehaute filed for a 3D printing patent involving the use of a laser to cure monomers (instead of UV light). The project was abandoned due to lack of funding by the French Centre for Scientific Research (CNRS). In 1986, Charles “Chuck” Hall filed for a patent in 3D printing for an SLA (stereolithography apparatus) machine. He also co-founded 3D systems corporation, which is the world leader in 3D printing technologies today.
Between 1988-1992 rapid innovations took place in this field. These involved SLS (Selective Laser Sintering) and FDM (Fused Deposition Modelling). SLS technology uses a powerful laser to sinter 3D printing material (powder form) into 3D models designed using a CAD software (STL file) . FDM technology uses thermoplastic filaments, which are melted and injected via nozzles, building a part layer-by-layer from a CAD file. The component cools down and solidifies to form the final 3D object. FDM is a popular 3D printing technology due to its ease of use for hobbyists and small businesses.
Between 1993-1995, ZCorp released their first 3D printer—the ZCorp Z402. The technology used was initially known as Zprinting, today it is also called ‘Color Jet’ or Binder Jetting. Binder Jetting technology also uses a powder bin, like SLS. Multiple parts can be printed in a single batch, and dimensional accuracies of 100 microns can be easily achieved. Parts can be made from sand, ceramics, and metals like stainless steel, Inconel, copper, titanium, and tungsten carbide.
Other important 3D printing technologies are Direct Metal Laser Sintering (DMLS), Electron Beam Melting (EBM), Direct Metal Deposition (DMD), Polyjet, Digital Light Processing (DLP), and Liquid Crystal Display (LCD).
Current & Future Trends:
As per Mordor Intelligence, 3D printing market was valued at $13.7 billion in 2020. This value is expected to reach $63.46 billion by 2026, at a CAGR is 29.48% over this forecast period (2021-2026). The largest market is North America, while the fastest growing market is Asia Pacific, especially China. Use of 3D printing is expected to grow in many industries, such as automotive, aerospace, defence, healthcare, construction, and architecture. A faster adoption of 3D printing is expected to be driven by advanced technologies such as Industry 4.0, Smart Factories, Robotics, AI and ML, CAD systems with simulations.
Major advantages of using 3D printing are:
- Reduction of manufacturing costs—Low setup time and cycle time.
- Reduction of dimensional errors—High precision for simple and complex geometries.
- Low cost of prototypes—No requirement of jigs & fixtures, and low wastage of raw material (after production).
- Shorter lead-time for prototypes—3D printing of parts takes a few minutes/hours for simple designs or small parts, and up to a few days for complex designs or large parts.
- Better Inventory Management—Small production batches, less requirement of raw materials (RM) and finished goods (FG), including warehouse space for storage.
- Prototyping market share of 3D printing is expected to rise to 50% by 2028. 3D printing of parts reduces the R&D costs and timelines for new projects. Firms can therefore experiment with new designs quickly and launch products with a high probability of success.
- Manufacturing as a Service (3D printing) has been on the rise in the past few years, especially for prototypes and small volume production. This trend would continue to grow in the post-pandemic world. Firms are faced with a choice to go with a 3D printing service or a traditional manufacturing company for outsourced production. These trends (below) indicate that online 3D printing services across many sectors would rise in the post-COVID world.
- Plastic components produced via injection moulding machines require expensive dies, which have a lead-time of 2-3 months or more. Each production batch size should be high to cover these costs and generate profits. For small volumes and/or complex designs, 3D printing is an excellent option except for mission-critical parts.
- Metal components produced via regular manufacturing methods involve punch press machines and expensive dies (lead-time of 2-3 months or more). To justify these costs and ensure profitability, each production batch size should be high. Other options are laser cutting, waterjet cutting, and plasma cutting, which are good for small batch sizes and complex 2D designs. These technologies have some limitations like high energy consumption, excess heat induced in the parts, and dimensional errors. CNC machines can be used to build 3D parts with simple to medium designs. This machining process is time consuming and involves significant wastage of raw materials. 3D printers can be a good alternative to produce complex 3D parts (non-mission critical) with higher dimensional accuracy, low wastage of raw materials, and lower post-processing requirements (annealing or heat treatment).
- Increased R&D investments in 3D printing technology is expected over the next 5-10 years, driven by both governments and private investors. Many sectors would benefit from advanced 3D printing services—manufacturing, automotive, defence, aviation, aerospace, and construction. Therefore, investments in 3D printing technologies linked with emerging technologies like artificial intelligence and cloud computing would have many applications (high profitability).
- Equipment Costs—Industrial 3D printers incorporate latest technologies to solve specific industry problems. They are not widely adopted by manufacturers due to high operating costs. Key issues involve a limited selection of raw materials that cost 3-5x more than on the open market, and high cost of annual maintenance contracts.
- Energy Consumption—3D printers consume 50-100 times more electricity for plastics than a similar injection moulding machine, and hundreds of times more for metals than traditional casting or machining. Today’s 3D printers cannot fully replace metal machining or injection moulding (plastic) processes due to high costs, and reliability/service-life or products.
- Hazardous Vapours—Thermoplastics like ABS (Acrylonitrile Butadiene Styrene) and PLA (Polylactic Acid) are popularly used for 3D printing. They release hazardous vapours known as volatile organic compounds (VOCs), and ultrafine particles (UFPs) or nanoparticles (1-100 nanometres, size 1 x 10-9 m.) during the printing process.
- VOCs generally include styrene, butanol, cyclohexanone, ethylbenzene, and others. Health effects due to their inhalation include irritation (eye, nose, and throat), nausea, and organ damage.
- UFPs can be immediately absorbed by living beings. According to experts, these inhaled nanoparticles can reach the blood, liver, and heart. Repeated exposure to these particles (medium to high concentrations) can cause adverse health effects.
- 3D printers should be placed in highly ventilated rooms, and people operating these machines should follow safety protocols (wear PPEs, respirators, etc.).
- Part-to-Part Variation—Serious flaws like powder trapped inside a part, microcracks, lack of fusion, presence of impurities/contamination prohibit adoption of 3D printing to safety-critical manufacturing (aircraft parts, medical devices).
- Lack of Industry-wide Standards— Manufacturing sector is driven by national & international standards for materials, machines, operators and engineers, and processes. Historically, 3D printing has been used only for prototypes or low volume production. As the manufacturing sector has recently recognised the potential of 3D printing, Additive Manufacturing (AM) standards are being developed now.
- Copyright Infringements—Counterfeit products made with 3D blueprints obtained illegally can be almost impossible to identify. This makes it very tough for law enforcement agencies to track down the criminals and punish them appropriately.
- Dangerous Weapons—Criminals and terrorists can easily create 3D printed weapons like knives, guns, explosives, etc. Such organizations also use 3D printing technology to create card readers for bank/ATM machines to swindle money.
- Limited Materials—Only a few types of plastics, metals, alloys, and ceramics can be used for 3D printing. They may be unsuitable for heavy-duty (high-performance) applications. 3D printed plastic and metal parts can vary in density, and tensile strength compared to similar injection moulded and machined parts (punch press machines, CNC machines, etc.) respectively.