Introduction to 3D Printing
Rapid prototyping, additive manufacturing and 3D printing all refer to the same technology that makes it possible to produce different physical 3D objects using CAD files.There are different types of 3D printing systems in use today. The primary ones are:
Filament: Pioneered mainly by Stratasys, fused deposition modelling (FDM) is an additive 3D printing process in which the raw material is fused together layer by layer. Since FDM was trademarked by Stratasys in 1992, other similar 3D printing technologies that used this technique were called fused filament fabrication (FFF). Essentially, they are very similar technologies and are popular for inexpensive and easily customizable 3D printing.
Vat Polymerization: This is a 3D printing process where a light source selectively cures a photopolymer resin in a vat. It is characterized by its use of ultraviolet (UV) light for curing purposes.Rather than airdrying, VAT polymerization printing uses ultraviolet light to selectively curephotopolymer resin in a vat to build objects. The two most common forms of VAT polymerization are SLA (Stereolithography) and DLP (Digital Light Processing).
Selective Laser Sintering (SLS): This type of 3D printing uses a laser beam to sinter powdered plastic material to create solid parts. The powder is preheated up to a temperature just below its melting point. The laser then scans the cross section of the 3D CAD model and melts and fuses the plastic powder to form one layer of the desired solid geometry. This process is repeated layer by layer till the entire object is completed.
Polyjet: These 3D printers utilize UV light to solidify photopolymer material. They are a part of material jetting 3D printers, but the name ‘Polyjet’ is copyrighted only by Stratasys. At the core of this technology are the numerous jetting heads that deliver precisely controlled streams of a photopolymer to the build platform. When UV light hits them, these liquid polymers solidify. Once the process is completed, the built platform moves down and repeats the process till the complete object is build.
Electronic Beam Melting (EBM): In EBM, fully dense metal components are created from a powder bed of metal powder and melted by a powerful electron beam. Each layer is melted according the CAD printing file sent to the 3D printer. This electron beam is managed through electromagnetic coils which allow for extremely fast and accurate beam control. EBM is used fairly regularly in industrial metal 3D printing. It is similar to SLS in that both 3D print from a powder bed through powder bed fusion.
There are many other 3D printing processes, but they are more or less variants of the established processes like above. Each 3D printing process has its own advantages and disadvantages. Printers that are inexpensive typically produce objects with lesser details than printers that produce excellent quality. Likewise, for the same quality of printing, printers that are fast are costlier than those that print at a slow rate. Ultimately, which 3D printer you buy depends on your needs and your budget.
Inkjet 3D Printing: Inkjet 3D printing uses a low-temperature, low-pressure process that involves the deposition of liquid materials or solid suspensions. The printing material is extruded through a small nozzle within a print head. As the print head raster scans over a surface, multiple layers are built up in a layer-by-layer process. Wax pattern making is a very old art in making jewellery and investment casting of metals. The high end 3D printers allow castable wax models with complex geometries, clean burnout and superior surface finish. Inkjet 3D printers are used in aerospace, jewellery making and medical devices. The finished product is ready to use as soon as it is printed - no finishing is required.
Sector wise use of 3D Printers
The 3D printing market was valued at USD 13.7 billion in 2020 and is expected to reach a value of USD 63.46 billion by 2026, at a CAGR of 29.48% over the forecast period (2021 - 2026). [Source: https://mordorintelligence.com/industry-reports/3d-printing-market]
Sector wise, the industrial machines, automobile and aerospace sector occupy a lion’s share in the use of 3D printers. Automobile industry especially latched on to the benefits of 3D printing technology quite early on. Once popular in North America, all automobile manufacturers from the world including those from India and Singapore now leverage the benefits of rapid prototyping, lower turnaround time, and low consumption of raw material and subsequently lower wastage, lower production costs and flexibility provided by 3D printing solutions. Using high quality 3D printers – like those from Stratasys - designers can create concept vehicles efficiently, or evaluate a new design of gear train in 3D quickly. 3D printing also helps reduce the production cost by printing some items like dashboard parts in-house.
Another sector that has adapted to 3D printing early on is the aerospace sector. 3D printers are useful at every stage of aeroplane manufacturing - from design communication to production. A low cost FDM 3D printer can produce a full-size landing gear enclosure quickly, while higher end 3D printers can create a high-detail, full-colour control board concept model of an aircraft. 3D printers add value to the aerospace industry by creating parts that are stronger and lighter than parts made using traditional manufacturing. Indeed, that is one of their major USP in this sector.Jigs and fixtures and mounting brackets are other examples where 3D printing has added value to this sector.
Industrial machines: 3D printing assists in improving the machine tool conception cycle. It allows users to 3D print different kinds of parts like concept models, objects with a complex geometry, and even finished parts.3D printers provide value to this sector by allowing users to create 3D printed parts efficiently, maintain a digital inventory of spare parts and then producing them quickly when needed, and create specialized and complicated parts that are not easy to manufacture by traditional machining.
Healthcare: 3D printers allow printing of prosthetics and dental implants. Since each body part can be customized exactly as per the individual’s requirements, 3D printing offers tremendous value addition in this field. 3D printing is often used in the healthcare industry to create physical models of 3D scans of people’s internal organs as well. This aids doctors and other healthcare professionals in surgical planning, proper diagnosis and management of patients.
Yet another key sector where 3D printers are making their presence felt is the educational sector. 3D printers enable kids to actually create and inspect various objects and study them in detail. Students of geography can print 3D topographic maps to understand features like mountains and valleys, chemistry students can print models of molecules, biology students can print and study various organs, cellular structure, etc. They can also be used for research by PhD students, and by engineering students for understanding technology & mechanical designs.
Apart from these sectors, 3D printers are now making their presence felt in other sectors like defence, electronics, etc. As India, Singapore and other Asian countries strive to catch up with their American and European counterparts, the use of 3D printing is set to rise.
In summary, 3D printers and 3D printing technology offer unique benefits that traditional processes just cannot offer. Rapid prototyping, custom created objects and objects with complex geometries can all be created with the help of 3D printers. As technology advances, the cost of 3D printers too is coming down and the quality of printing is improving. Innovative printing materials like metals and food have added to the benefits offered by 3D printing.