3D PRINTING

Submitted By:

Abhishek Singh (CSE/12/25)Waivaw Upadhyay (CSE/12/26)Gajendra Kumar (CSE/12/27)

ACKNOWLEDGEMENT

We would like to express our sincere gratitude toward all those who have helped us in completing this seminar. We are grateful to our Principal, Mr. Ashok Kumar, and our Head of Department, Dr. Premananda Jana, for providing us with the opportunity to perform this seminar.We are also thankful to our seminar co-ordinators, Mrs. Rachita Ghoshhazra, Mr. Avijit Bose and Mr. Pusphen Lahiri for their constant support and encouragement. This seminar would not be possible without them.Our classmates need a special mention, for extending their constant help.Last but not the least, we would like to thank our parents to whom we owe the success of this and all other works that we will undertake in future.

TABLE OF CONTENTS

Contents Aim & Objective Scope What is 3D Printing History of 3D Printing Methods of 3D Printing Commercial & Personal 3D Printers Applications Future of 3D Printing Conclusion ReferencesPage number(s)123-45-910-1819-2021-22232425

AIM AND OBJECTIVE

The seminar was structured in a way to provide the participant a glimpse of the future world that will be completely changed by a simple box - a 3D printer.The seminar intended to take its participants in a time travel of the past, present and the possible future of 3D printing.It also aimed to provide the technical insights into the basic working of a 3D printer and going across specific methods of 3D printing technology.The seminar makes an attempt to prepare its participants for the miraculous medical possibilities that 3D printers could bring up in the future.

Page | 16

SCOPEThe seminar covers the basic concept of a 3D printer, its differences with a usual 2D printer, and its obvious advantages.The seminar addresses three key themes such as the history of 3D printing, the methods and working of a present 3D printer along with the challenges it faces today, and possible future opportunities it could bring about.Given the time limit of the seminar, it was only possible to go into the details of few 3D working methods including stereolithography, selective laser sintering, and fused deposition modelling.Other methods such as digital light processing, electron beam melting will be just mentioned without going into their details.

What is 3D printing?3D 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 entire object is created. Each of these layers can be seen as a thinly sliced horizontal cross-section of the eventual object. How does 3D Printing work?It all starts with making a virtual design of the object you want to create. This virtual design is made in aCAD(Computer Aided Design) file using a 3D modeling program (for the creation of a totally new object) r with the use of a 3D scanner (to copy an existing object). This scanner makes a 3D digital copy of an object and puts it into a 3D modeling program.To prepare the digital file created in a 3D modeling program for printing, the software slices the final model into hundreds or thousands of horizontal layers. When this prepared file is uploaded in the 3D printer, the printer creates the object layer by layer. The 3D printer reads every slice (or 2D image) and proceeds to create the object blending each layer together with no sign of the layering visible, resulting in one three dimensional object.

Is it 3D Printing or Additive Manufacturing?The term 3D printing is the common term for the correct manufacturing term of additive manufacturing. But 3D printing will remain the term of choice as who really is going to run around saying things like, Im going to go additively manufacture a new iPhone case. No, they are going to 3D print it. It just sounds so much cooler too, doesnt it?

Theres no way subtractive manufacturing is going to make something like this in one clean run.So what the heck is additive manufacturing? Someday soon enough in the future, people will look back and view our current manufacturing processes as we today view something such as blacksmithing. Whats interesting about that last sentence is that much of todays manufacturing processes are actually very similar to blacksmithing. Both are whats called subtractive manufacturing.Subtractive manufacturing relies upon the removal of material to create something. The blacksmith hammered away at heated metal to create a product. Today, a CNC machine cuts and drills and otherwise removes material from a larger initial block of material to create a product. Its inefficient and wasteful. Other manufacturing techniques abound but they all essentially whittle down raw material into a product.As youve already surmised, additive manufacturing creates something by adding material to the object. Some here, some there, and no where its not needed. No waste. Very efficient. Youll read about many types of 3D printers, but no matter the technology involved, its additive.

A brief history of 3D PrintingThe inception of 3D printing can be traced back to 1976, when the inkjet printer was invented. In 1984, adaptations and advances on the inkjet concept morphed the technology from printing with ink to printing with materials. In the decades since, a variety of applications of 3D printing technology have been developed across several industries. The following is a brief history of the major milestones along the way.

1984, THE BIRTH OF 3D PRINTING

Charles Hull, later the co-founder of 3D Systems, invents stereolithography, a printing process that enables a tangible 3D object to be created from digital data. The technology is used to create a 3D model from a picture and allows users to test a design before investing in a larger manufacturing program.

1992, BUILDING PARTS LAYER BY LAYER

The 1st SLA (stereolithographic apparatus) machine is produced by 3D Systems. The machines process involves a UV laser solidifying photopolymer, a liquid with the viscosity and color of honey that makes three-dimensional parts layer by layer. Although imperfect, themachine proves that highly complex parts can be manufactured overnight.

1999, ENGINEERED ORGANS BRING NEW ADVANCES TO MEDICINE

The 1st lab-grown organ is implanted in humans when young patients undergo urinary bladder augmentation using a 3-D synthetic scaffold coated with their own cells. The technology, developed by scientists at the Wake Forest Institute for Regenerative Medicine*, opened the door to developing other strategies for engineering organs, including printing them. Because they are made with a patients own cells, there is little to no risk of rejection.

2002, A WORKING 3D KIDNEY

Scientists engineer a miniature functional kidney that is able to lter blood and produce diluted urine in an animal. The development led to research at the Wake Forest Institute for Regenerative Medicine that aims to print organs and tissues using 3D printing technology.

2005, OPEN-SOURCE COLLABORATION WITH 3D PRINTING

Dr. Adrian Bowyer at University of Bath founds RepRap, an open-source initiative to build a 3D printer that can print most of its own components. The vision of this project is to democratize manufacturing by cheaply distributing RepRap units to individuals everywhere, enabling them to create everyday products on their own.

2006,SLS LEADS TO MASS CUSTOMIZATION IN MANUFACTURING

The 1st SLS (selective laser sintering) machine becomes viable. This type of machine uses a laser to fuse materials into 3D products. This breakthrough opens the door to mass customization and on-demand manufacturing of industrial parts, and later, prostheses. That same year Objet, a 3D printing systems and materials provider, creates a machine capable of printing in multiple materials, including elastomers and polymers. The machine permits a single part to be made with a variety of densities and material properties.

2008, THE FIRST SELFREPLICATING PRINTER

Following its launch in 2005, RepRap Project releases Darwin, the 1st self-replicating printer that is able to print the majority of its own components, allowing users who already have one to make more printers for their friends.

2011, WORLDS FIRST 3D-PRINTED ROBOTIC AIRCRAFT

Engineers at the University of Southampton design and y the worlds 1st 3D-printed aircraft. This unmanned aircraft is built in seven days for a budget of 5,000. 3D printing allows the plane to be built with elliptical wings, a normally expensive feature that helps improve aerodynamic efficiency and minimizes induced drag.

2011, WORLDS FIRST 3D-PRINTED CAR

Kor Ecologic unveils Urbee, a sleek, environmentally friendly prototype car with a complete 3D-printed body at the TEDx Winnipeg conference in Canada. Designed to be fuel efficient and inexpensive, Urbee gets 200 mpg highway and 100 mpg city. It is estimated to retail for $10,000 to $50,000 if it becomes commercially viable.

2012, 3D-PRINTED PROSTHETIC JAW IS IMPLANTED

Doctors and engineers in the Netherlands use a 3D printer made by LayerWise to print a customized three-dimensional prosthetic lower jaw, which is subsequently implanted into an 83-year old woman suffering from a chronic bone infection. This technology is currently being explored to promote the growth of new bone tissue.

3D Printing Methods

Stereolithography

Stereolithography (SL) is widely recognized as the first 3D printing process; it was certainly the first to be commercialised. SL is a laser-based process that works with photopolymer resins, that react with the laser and cure to form a solid in a very precise way to produce very accurate parts. It is a complex process, but simply put, the photopolymer resin is held in a vat with a movable platform inside. A laser beam is directed in the X-Y axes across the surface of the resin according to the 3D data supplied to the machine (the .stl file), whereby the resin hardens precisely where the laser hits the surface. Once the layer is completed, the platform within the vat drops down by a fraction (in the Z axis) and the subsequent layer is traced out by the laser. This continues until the entire object is completed and the platform can be raised out of the vat for removal.Because of the nature of the SL process, it requires support structures for some parts, specifically those with overhangs or undercuts. These structures need to be manually removed.In terms of other post processing steps, many objects 3D printed using SL need to be cleaned and cured. Curing involves subjecting the part to intense light in an oven-like machine to fully harden the resin.Stereolithography is generally accepted as being one of the most accurate 3D printing processes with excellent surface finish. However limiting factors include the post-processing steps required and the stability of the materials over time, which can become more brittle.Digital Light Processing (DLP)

DLP or digital light processing is a similar process to stereolithography in that it is a 3D printing process that works with photopolymers. The major difference is the light source. DLP uses a more conventional light source, such as an arc lamp, with a liquid crystal display panel or a deformable mirror device (DMD), which is applied to the entire surface of the vat of photopolymer resin in a single pass, generally making it faster than SL.Also like SL, DLP produces highly accurate parts with excellent resolution, but its similarities also include the same requirements for support structures and post-curing. However, one advantage of DLP over SL is that only a shallow vat of resin is required to facilitate the process, which generally results in less waste and lower running costs.Laser Sintering / Laser Melting

Laser sintering and laser melting are interchangeable terms that refer to a laser based 3D printing process that works with powdered materials. The laser is traced across a powder bed of tightly compacted powdered material, according to the 3D data fed to the machine, in the X-Y axes. As the laser interacts with the surface of the powdered material it sinters, or fuses, the particles to each other forming a solid. As each layer is completed the powder bed drops incrementally and a roller smoothes the powder over the surface of the bed prior to the next pass of the laser for the subsequent layer to be formed and fused with the previous layer.The build chamber is completely sealed as it is necessary to maintain a precise temperature during the process specific to the melting point of the powdered material of choice. Once finished, the entire powder bed is removed from the machine and the excess powder can be removed to leave the printed parts. One of the key advantages of this process is that the powder bed serves as an in-process support structure for overhangs and undercuts, and therefore complex shapes that could not be manufactured in any other way are possible with this process.However, on the downside, because of the high temperatures required for laser sintering, cooling times can be considerable. Furthermore, porosity has been an historical issue with this process, and while there have been significant improvements towards fully dense parts, some applications still necessitate infiltration with another material to improve mechanical characteristics.Laser sintering can process plastic and metal materials, although metal sintering does require a much higher powered laser and higher in-process temperatures. Parts produced with this process are much stronger than with SL or DLP, although generally the surface finish and accuracy is not as good.Extrusion / FDM / FFF

3D printing utilizing the extrusion of thermoplastic material is easily the most common and recognizable 3DP process. The most popular name for the process is Fused Deposition Modelling (FDM), due to its longevity, however this is a trade name, registered by Stratasys, the company that originally developed it. Stratasys FDM technology has been around since the early 1990s and today is an industrial grade 3D printing process. However, the proliferation of entry-level 3D printers that have emerged since 2009 largely utilize a similar process, generally referred to as Freeform Fabrication (FFF), but in a more basic form due to patents still held by Stratasys. The earliest RepRap machines and all subsequent evolutions open source and commercial employ extrusion methodology. However, following Stratasys patent infringement filing against Afiniathere is a question mark over how the entry-level end of the market will develop now, with all of the machines potentially in Stratasys firing line for patent infringements.The process works by melting plastic filament that is deposited, via a heated extruder, a layer at a time, onto a build platform according to the 3D data supplied to the printer. Each layer hardens as it is deposited and bonds to the previous layer.Stratasys has developed a range of proprietary industrial grade materials for its FDM process that are suitable for some production applications. At the entry-level end of the market, materials are more limited, but the range is growing. The most common materials for entry-level FFF 3D printers are ABS and PLA.The FDM/FFF processes require support structures for any applications with overhanging geometries. For FDM, this entails a second, water-soluble material, which allows support structures to be relatively easily washed away, once the print is complete. Alternatively, breakaway support materials are also possible, which can be removed by manually snapping them off the part. Support structures, or lack thereof, have generally been a limitation of the entry level FFF 3D printers. However, as the systems have evolved and improved to incorporate dual extrusion heads, it has become less of an issue.In terms of models produced, the FDM process from Stratasys is an accurate and reliable process that is relatively office/studio-friendly, although extensive post-processing can be required. At the entry-level, as would be expected, the FFF process produces much less accurate models, but things are constantly improving.The process can be slow for some part geometries and layer-to-layer adhesion can be a problem, resulting in parts that are not watertight. Again, post-processing using Acetone can resolve these issues.

InkjetThere are two 3D printing process that utilize a jetting technique:

Binder jetting: where the material being jetted is a binder, and is selectively sprayed into a powder bed of the part material to fuse it a layer at a time to create/print the required part. As is the case with other powder bed systems, once a layer is completed, the powder bed drops incrementally and a roller or blade smoothes the powder over the surface of the bed, prior to the next pass of the jet heads, with the binder for the subsequent layer to be formed and fused with the previous layer.Advantages of this process, like with SLS, include the fact that the need for supports is negated because the powder bed itself provides this functionality. Furthermore, a range of different materials can be used, including ceramics and food. A further distinctive advantage of the process is the ability to easily add a full colour palette which can be added to the binder.The parts resulting directly from the machine, however, are not as strong as with the sintering process and require post-processing to ensure durability.

Material jetting: a 3D printing process whereby the actual build materials (in liquid or molten state) are selectively jetted through multiple jet heads (with others simultaneously jetting support materials). However, the materials tend to be liquid photopolymers, which are cured with a pass of UV light as each layer is deposited.The nature of this product allows for the simultaneous deposition of a range of materials, which means that a single part can be produced from multiple materials with different characteristics and properties. Material jetting is a very precise 3D printing method, producing accurate parts with a very smooth finish.Selective Deposition Lamination (SDL)

SDL is a proprietary 3D printing process developed and manufactured by Mcor Technologies. There is a temptation to compare this process with the Laminated Object Manufacturing (LOM) process developed by Helisys in the 1990s due to similarities in layering and shaping paper to form the final part. However, that is where any similarity ends.The SDL 3D printing process builds parts layer by layer using standard copier paper. Each new layer is fixed to the previous layer using an adhesive, which is applied selectively according to the 3D data supplied to the machine. This means that a much higher density of adhesive is deposited in the area that will become the part, and a much lower density of adhesive is applied in the surrounding area that will serve as the support, ensuring relatively easy weeding, or support removal.After a new sheet of paper is fed into the 3D printer from the paper feed mechanism and placed on top of the selectively applied adhesive on the previous layer, the build plate is moved up to a heat plate and pressure is applied. This pressure ensures a positive bond between the two sheets of paper. The build plate then returns to the build height where an adjustable Tungsten carbide blade cuts one sheet of paper at a time, tracing the object outline to create the edges of the part. When this cutting sequence is complete, the 3D printer deposits the next layer of adhesive and so on until the part is complete.

SDL is one of the very few 3D printing processes that can produce full colour 3D printed parts, using a CYMK colour palette. And because the parts are standard paper, which require no post-processing, they are wholly safe and eco-friendly. Where the process is not able to compete favourably with other 3D printing processes is in the production of complex geometries and the build size is limited to the size of the feedstock

Electron Beam Melting (EBM)

The Electron Beam Melting 3D printing technique is a proprietary process developed by Swedish company Arcam. This metal printing method is very similar to the Direct Metal Laser Sintering (DMLS) process in terms of the formation of parts from metal powder. The key difference is the heat source, which, as the name suggests is an electron beam, rather than a laser, which necessitates that the procedure is carried out under vacuum conditions.EBM has the capability of creating fully-dense parts in a variety of metal alloys, even to medical grade, and as a result the technique has been particularly successful for a range of production applications in the medical industry, particularly for implants..Commercial 3D printers

While most people have yet to even hear the term 3D printing, the process has been in use for decades. Manufacturers have long used the printers in the design process to create prototypes for traditional manufacturing. But until the last few years, the equipment has been expensive and slow.Now, fast 3D printers can be had for tens of thousands of dollars, and end up saving the companies many times that amount in the prototyping process. For example, Nike uses 3D printers to create multi-colored prototypes of shoes. They used to spend thousands of dollars on a prototype and wait weeks for it. Now, the cost is only in the hundreds of dollars, and changes can be made instantly on the computer and the prototype reprinted on the same day.Some companies are using 3D printers for short run or custom manufacturing, where the printed objects are not prototypes, but the actual end user product. As the speeds of 3D printing go up and the prices come down, look for more and more of this. And expect more availability of personally customized products.Personal 3D PrintersSo far weve only talked about commercial 3D printers. There is a whole other world of 3D printers: personal and DIY hobbyist models. And they are getting cheap, with prices typically in the range of $300 $2,000.

The RepRap open source project really ignited this hobbyist market in the same way the Apple I microcomputer ignited the hobbyist desktop computer market in the late 1970s. For about a thousand dollars, people have been able to buy the RepRap kit and put together their own personal 3D printer, complete with any customizations they were capable of making. And whats more, these printers print most of the parts for more printers. RepRap is short for replicating rapid prototyper, so complete self-replication, including electronic circuit boards, is the goal.The interest in RepRap spawned scores of other low-cost 3D printers, both DIY and fully-assembled, and as the prices keep coming down, it puts 3D printers into more and more and more hands.But do you have to be an engineer or a 3D modeling expert to create 3D models on your own 3D printer? No, not at all. While complex and expensive CAD software like AutoCAD and Solidworks have a steep learning curve, there are a number of other programs, many free, that are very easy to learn. The free version of Google SketchUp, for example, is very popular for its ease of use; and the free Blender program is popular for its advanced features.If you dont have your very own 3D printer, not to worry, there are 3D printing service bureaus like Shapeways and Ponoko that can very inexpensively print and deliver an object from a digital file that you simply upload to their user-friendly website. Its almost as easy as ordering a custom t-shirt from Cafepress or Zazzle.ApplicationsApplications include design visualization, prototyping/CAD, metal casting, architecture, education, geospatial, healthcare and entertainment/retail.Other applications would include reconstructing fossils in paleontology, replicating ancient and priceless artifacts in archaeology, reconstructing bones and body parts in forensic pathology and reconstructing heavily damaged evidence acquired from crime scene investigations.In 2007 the use of 3D printing technology for artistic expression was suggested. Artists have been using 3D printers in various ways.As of 2010 3D printing technology was being studied by biotechnology 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. Several terms have been used to refer to this field of research like: organ printing, bio-printing, and computer-aided tissue engineering.

3D Printing Aids Heart, Spine SurgeonsAdvancements in other areas support Dr. Rybickis statement. The benefits of using 3-D printing to create a 3-D model of the heart were a major point of emphasis at the EuroEcho-Imaging 2014 annual meeting of the European Association of Cardiovascular Imaging (EACVI) last summer.Specifically, in fall 2014, a 3-D heart model helped surgeons at Morgan Stanley Childrens Hospital in New York repair a congenital heart defect in a 2-week-old baby. With the advent of 3-D imaging, now we can clearly evaluate the structure of the heart in different planes, said Patrizio Lancellotti, M.D., Ph.D., EACVI president, in a written statement. With this novel technology we will gain insights into the interactions between the valves and the ventricles, the valves and the aorta, and the valves and the left atrium.3-D printing itself depends on the advanced imaging modalities and protocols to generate source DICOM images amenable for printing. For certain applications such as cardiac congenital anomalies, advanced MR protocols have proven invaluable to generate 3-D printed models," Dr. Rybicki said. "For other applications, particularly when bony structures are printed, thin section CT images will suffice.In another breakthrough procedure in 2014, 3-D printing was used in complex spinal cord surgery. Doctors from the Peking University Third Hospital in Beijing successfully replaced a section of cancerous vertebra in a 12-year-old boys neck with a piece created on a 3-D printer.3-D printing was also successfully used in at least five other life-changing surgeries during 2014, including replacing an upper jaw, forming a new skull, spinal-fusion surgery, and heel and hip implants.

Future of 3-D Printing is Bright, but Cost Remains an ObstacleWith advanced imaging as the cornerstone, the future of 3-D printing is bursting with possibilities for all of healthcare and holds the potential to completely reshape medicine. But barriersprimarily training opportunities and costprevent the technology from becoming widely implemented in everyday practice anytime soon.Already 3-d printing is providing remarkable results in planning complex interventions in the heart, the spine and for a growing list of other procedures. At RSNA 2014, a research team led by Frank J. Rybicki, M.D., Ph.D., former director of the Applied Imaging Science Lab at Brigham and Womens Hospital (BWH) in Boston, and incoming chair and professor at the University of Ottawa, Canada, demonstrated how they utilized CT and 3-D printing to recreate life-size models of patients skulls and soft tissues to assist in face transplantation surgery.In 2011, Dr. Rybicki, working with the BWH surgical team led by Bohdan Pomahac, M.D., performed the first successful full-face transplantation in the U.S. and the team has since completed four more full-face procedures in addition to other partical face transplants. Dr. Rybicki explained that 3-D visualization was the precursor to 3-D printing and took place in 3-D labs. The underlying idea was that DICOM (Digital Imaging and Communications in Medicine) data sets contained more useful information than was being extracted via axial images alone, or even the rendering of a 3-D volume on a 2-D monitor (the essence of 3-D visualization). The availability of 3-D printing was the next logical step in technology and application to patient care, Dr. Rybicki said.There are strong parallels between 3-D printing today and early 3-D labs, Dr. Rybicki said. Even more information can be obtained in DICOM images via a printed model in your hands, and this has borne out in many fields.3-D printing impacts far more routine surgeries than face transplantation, and it is here to stay, Dr. Rybicki added.

Conclusion-3D Printing is a Game Changer

Instantly printing parts and entire products, anywhere in the world, is a game changer. But it doesnt stop there. 3D printing will affect almost every aspect of industry and our personal lives.Medicine will forever be changed as new bioprinters actually print human tissue for both pharmaceutical testing and eventually entire organs and bones.Architecture and construction are changing as well. Now, 3D-printed models of complex architectural drawings are created quickly and inexpensively, rather than the expensive and time-consuming process of handcrafting models out of cardboard. And experimental, massive 3D printers are printing concrete structures, with the goal of someday creating entire buildings with a 3D printer.Art is already forever changed. Digital artists are creating magnificent pieces that seem almost impossible to have been made by traditional methods. From sculptures to light fixtures, beautiful objects no longer need to be handcrafted, just designed on a computer.And there are developments where you least expect them: for example, archeologists can 3D scan priceless and delicate artifacts, and then print copies of them so they can handle them without fear of breakage. Replicas can be easily made and distributed to other research facilities or museums. It has been used to create a full-size reproduction of King Tutankhamuns mummy and to repair Rodins sculpture, The Thinker.References https://gigaom.com/2013/10/02/the-future-of-consumer-3d-printing-whats-real-whats-coming-and-whats-hype/ http://3dprintmygift.tumblr.com/ http://www.huffingtonpost.com/2013/02/20/scientists-create-new-ear_n_2728612.html?utm_hp_ref=technology&ir=India http://www.bbc.com/news/technology-20972018 http://computer.howstuffworks.com/3-d-printing.html http://rsna.org/NewsDetail.aspx?id=15035 http://3dprinting.com/ http://www.3dprinter.net/reference/what-is-3d-printing