Additive manufacturing, commonly referred to as 3d printing, is a manufacturing technique that rises in the 1980’s mainly focused on engineering prototyping. Current advances in the precision and cost of the techniques, as well as the widespread use of 3d designing have increased 3d printing’s scope of use from high-end engineering prototypes to a large variety of uses in manufacturing. 3d printing improve the processing time, decrease waste, and increase the level of customization of certain products by eliminating the need for the specialty tooling and dies that are traditionally used in manufacturing. In addition, the ability to physically print difficult shapes based on a computer model has given rise to new products that would otherwise be simply impossible to create. The various fields have taken advantage of this technology by printing 3d objects.

1. A
Seminar Report On
“3D PRINTING: AN EMERGING ERA OF FUTURE
PRINTING”
Submitted In Partial Fulfillment of the Requirement
For The Award of Degree of Bachelor of Engineering
In Computer Science & Engineering
North Maharashtra University, Jalgaon
Submitted By
Mr. Pravin Ahirwar
Computer Science & Engineering
Shri Sant Gadge Baba
College of Engineering and Technology, Bhusawal
North Maharashtra University, Jalgaon
2014-15

2. ABSTRACT
Additive manufacturing, commonly referred to as 3d printing, is a manufacturing
technique that rises in the 1980’s mainly focused on engineering prototyping. Current
advances in the precision and cost of the techniques, as well as the widespread use of 3d
designing have increased 3d printing’s scope of use from high-end engineering prototypes
to a large variety of uses in manufacturing. 3d printing improve the processing time,
decrease waste, and increase the level of customization of certain products by eliminating
the need for the specialty tooling and dies that are traditionally used in manufacturing. In
addition, the ability to physically print difficult shapes based on a computer model has
given rise to new products that would otherwise be simply impossible to create. The
various fields have taken advantage of this technology by printing 3d objects.

3. 1. INTRODUCTION
The process of making a three dimensional solid object from digital model or
other electronic data is called 3d printing. 3d printing is additive manufacturing
technology [1]
. In an additive process an object is created by laying down successive
layers of material under computer control until the entire object is created[5]
. Each of
these layers can be seen as a thin sliced horizontal cross-section of the eventual object.
Early AM equipment and materials were developed in the 1980s [6]
. Chuck
Hull of 3D Systems Corp [7]
, in 1984 invented a process known as stereolithography using
UV lasers to cure photopolymers. Hull also explicates the STL file format widely
accepted by 3D printing software, as well as the digital cutting and infill strategies
common today. In 1990, the plastic extrusion technology mostly associated with the term
"3D printing" was commercialized by Stratasys under the name fused deposition
modeling (FDM). In 1995, Z Corporation commercialized an MIT-developed additive
process under the trademark 3D printing (3DP), referring at that time to a proprietary
process inkjet deposition of liquid binder on powder. 3d printing has many applications
such as architecture, construction (AEC), automotive, industrial design, automotive,
military, engineering, dental and medical industries, biotech, fashion, education,
geographic information systems, food, and many fields [8]
.

4. 2. THE PRINCIPLE OF 3D PRINTING TECHNOLOGY
The 3d printing technology is used for both prototyping and specialized
manufacturing, with utilization in industrial design, automotive industry, aerospace,
architecture and medical [9]
.
STEP 1: MODELING
The first step of 3d printing is digital modeling .3d printing takes models from
computer-aided design (CAD) or animation modeling software and “slices” them into
digital cross-sections, so that the machine can use them as a general rule to print.
Depending on the machine used, binding material or a material is deposited on the
platform until the material layering is complete and the final 3d model has been printed.
Before printing a 3D model from an STL file, it must first 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 printer. Several open
source slicer programs exist, including Skeinforge, Slic3r, KISSlicer, and Cura.

5. STEP 2: PRINTING
The second step is printing. In this step, the machine reads the structure from an
STL file and lays down successive layers of liquid, powder, or other materials to make
the model from a series of cross-sections. At last, the 3D-printed object is completed
according to the design. Some of the 3D printing techniques are capable of using multiple
materials in the course of constructing parts and some may also utilize supports when
building.

6. STEP 3: FINISHING
Supports can be removed or dissolve upon completion of the print and the final
object can be obtained. Post processing may be needed for some 3d-printed objects.
Though the printer-produced resolution is sufficient for many applications, printing a
slightly oversized version of the desired object in standard resolution and then removing
material with a higher-resolution subtractive process can achieve greater precision [18][19]
.

7. How it works
It all starts with making a virtual design of the object you want to create. This
virtual design is made in a CAD (Computer Aided Design) file using a 3D modeling
program (for the creation of a totally new object) ór 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.

8. Figure 3. A flowchart of 3d printer
Figure 3. shows the flowchart for 3d printer. The model to be manufactured is
built up a layer at a time. A layer of powder is automatically deposited in the model tray.
The print head then applies resin in the shape of the model. The layer dries solid almost
immediately. The model tray then moves down the distance of a layer and another layer
of power is deposited in position, in the model tray. The print head again applies resin in
the shape of the model, binding it to the first layer. This sequence occurs one layer at a
time until the model is complete.

9. 3. METHODS AND TECHNOLOGIES
A large number of additive processes including selective laser sintering
(SLS), stereolithography (SLA), fused deposition modeling (FDM), and direct metal laser
sintering (DMLS) are available for 3d printing. They differ themselves in the materials
that can be used and in the way the layers are deposited to create parts [2]
.
3.1 STEREOLITHOGRAPHY (SLA)
The main technology in which photopolymerization is used to produce a solid
part from a liquid is SLA. This technology employs a large vessel of liquid ultraviolet
curable photopolymer resin and an ultraviolet laser to build the object’s layers one at a
time[14]
.For every layer, the laser beam traces a cross-section of the part pattern on the
surface of the liquid resin. Revelation 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 stage 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, recoating it
with new material. On this new liquid surface, the following layer model is traced, joining
the previous layer. The complete 3d objects are formed by this plan. Stereolithography
requires the utilization of supporting structures which provide to attach the part to the
elevator platform [15][16]
.

10. 3.2 SELECTIVE LASER SINTERING (SLS)
This technology uses a high power laser to fuse small mites of plastic, metal,
or glass powders into a mass that has the desired 3d shapes. The laser selectively fuses the
powdered material by scanning the layers generated by the 3d designing program on the
surface of a powder bed. When each cross-section is scanned, the powder platform is
lowered by one layer thickness. After a new layer of material is applied on top and the
process is repeated until the object is completed.
All untouched powder remains as it is and becomes a support structure for the
object. Therefore there is no need for any sustain structure which is an advantage over
SLS and SLA. All remaining powder can be used for the next printing [11][12]
.

11. 3.3 FUSED DEPOSITION MODELING (FDM)
FDM begins with a software process which processes an STL file
(stereolithography file format), mathematically slicing and orienting the model for the
build process. If required, support structures may be generated. The machine may
dispense multiple materials to achieve different goals: For example, one may use one
material to build up the model and use another as a soluble support structure, or one could
use multiple colors of the same type of thermoplastic on the same model.
The model or part is produced by extruding small beads of thermoplastic material
to form layers as the material hardens immediately after extrusion from the nozzle.
A plastic filament or metal wire is unwound from a coil and supplies material to
an extrusion nozzle which can turn the flow on and off. There is typically a worm-drive
that pushes the filament into the nozzle at a controlled rate.
The nozzle is heated to melt the material. The thermoplastics are heated past their
glass transition temperature and are then deposited by an extrusion head.
The nozzle can be moved in both horizontal and vertical directions by a
numerically controlled mechanism. The nozzle follows a tool-path controlled by a
computer-aided manufacturing (CAM) software package, and the part is built from the
bottom up, one layer at a time. Stepper motors or servo motors are typically employed to

12. move the extrusion head. The mechanism used is often an X-Y-Z rectilinear design,
although other mechanical designs such as deltabot have been employed.
Although as a printing technology FDM is very flexible, and it is capable of
dealing with small overhangs by the support from lower layers, FDM generally has some
restrictions on the slope of the overhang, and cannot produce unsupported stalactites.
Myriad materials are available, such as ABS, PLA, polycarbonate, polyamides,
polystyrene, lignin, among many others, with different trade-offs between strength and
temperature properties [13]
.
3.4 DIRECT METAL LASER SINTERING (DMLS)
The DMLS is an additive manufacturing technique that uses a laser as the
power source to sinter powdered material (typically metal), aiming the laser automatically
at points in space defined by a 3d model, binding the material together to create a solid
structure.
The DMLS process involves use of a 3d CAD model whereby a .stl file is
created and sent to the machine’s software. A technician works with this 3D design to
properly orient the geometry for part building and adds supports structure as appropriate.
Once this "build file" has been completed, it is gash into the layer thickness the machine

13. will build in and downloaded to the DMLS machine allowing the build to start. The
DMLS machine uses a high powered 200 watt Yb fiber optic laser. Inner part of the build
chamber area, there is a material allotting platform and a build platform along with a
recoated blade used to move new powder on the build platform. The technology combine
metal powder into a solid part by melting it locally using the focused laser beam. Parts are
made up additively layer by layer, usually using layers 20 micrometers thick. This
process allows for highly tangled geometries to be created directly from the 3d CAD data,
automatically, in hours and without any tooling. DMLS is a process, producing parts with
high accuracy and detail resolution and good surface quality [10]
.
3.5 Laminated object manufacturing (LOM)
Laminated object manufacturing (LOM) is a rapid prototyping system
developed by Helisys Inc. (Cubic Technologies is now the successor organization of
Helisys) In it, layers of adhesive-coated paper, plastic, or metal laminates are successively
glued together and cut to shape with a knife or laser cutter. Objects printed with this
technique be additionally modified by machining or drilling after printing. Typical layer
resolution for this process is defined by the material feedstock and usually ranges in
thickness from one to a few sheets of copy paper.[26]
The process is performed as follows:

14. 1. Sheet is adhered to a substrate with a heated roller.
2. Laser traces desired dimensions of prototype.
3. Laser cross hatches non-part area to facilitate waste removal.
4. Platform with completed layer moves down out of the way.
5. Fresh sheet of material is rolled into position.
6. Platform moves up into position to receive next layer.
7. The process is repeated.
3.6Electron beam melting
Electron beam melting (EBM) is a type of additive manufacturing (AM) for
metal parts that was developed by Arcam AB in Sweden. It is often classified as a rapid
manufacturing method. It is similar to selective laser melting (SLM), the main difference
being that EBM uses an electron beam as its power source. EBM technology
manufactures parts by melting metal powder layer by layer with an electron beam in a
high vacuum. Unlike in the sintering techniques of selective laser sintering (SLS) and
direct metal laser sintering (DMLS), parts produced by the melting techniques of EBM
and SLM are fully dense, void-free, and extremely strong.
This solid freeform fabrication method produces fully dense metal parts
directly from metal powder with characteristics of the target material. The EBM machine

15. reads data from a 3D CAD model and lays down successive layers of powdered material.
These layers are melted together utilizing a computer controlled electron beam. In this
way it builds up the parts. The process takes place under vacuum, which makes it suited
to manufacture parts in reactive materials with a high affinity for oxygen, e.g. titanium.[3]
The melted material is from a pure alloy in powder form of the final material to be
fabricated (no filler). For that reason the electron beam technology doesn't require
additional thermal treatment to obtain the full mechanical properties of the parts. That
aspect allows classification of EBM with selective laser melting (SLM) where competing
technologies like SLS and DMLS require thermal treatment after fabrication. Compared
to SLM and DMLS, EBM has a generally superior build rate because of its higher energy
density and scanning method.
4. 3D PRINTING CAPABLITIES
As estimated, this current technology has smoothed the path for numerous new
possibilities in various fields. The below details of the advantages of 3d printing in certain
fields.
[1] Product formation is presently the main use of 3d printing technology. These
machines enable designers and engineers to test out ideas for dimensional
products inexpensive before committing to expensive tooling and manufacturing
processes.
[2] In Medical Field, Surgeons are using 3d printing machines to print body parts for
complicated surgeries. Other machines are used to construct bone grafts for
patients who have suffered from injuries. Looking in the future, scientists are
working on creating replacement organs.

16. [3] Architects need to create mockups of their designs. 3d printing permits them to
come up with these mockups in a short period of time and with appropriateness.
[4] 3d printing enables artists to create objects that would be incredibly complex,
costly, or time intensive.
5. 3D PRINTING SAVES TIME AND COST
Creating complete design in a single process using 3d printing has great favor.
This innovative technology has been proven to save enterprise time, manpower and
money. Companies providing 3d printing solutions have brought to life an efficient
product.
6) CURRENT APPLICATION OF 3D PRINTING
6.1 FOOD
Food is one of primary ingredients of life which is at the base of the pyramid
of human needs. Leading the food industry to the digital age is one of the essential
applications of 3d printing. Applying this technology permit fast automated and repeated
processes, independent in design, as well as allowing large and easy variability of the
cooking process which can be customized for each region or individual. By using robotic
layer based on food printing systems which allows the recipe to be digitized and saved in
order to make very repeatable and high quality dishes without any operator error. The
shape and decoration of the recipe can be design based on the customer or the occasion
[20][21].
.
6.2 EDUCATION
The education system plays an important role in helping people to achieve
their full potential. 3d printing can improve the learning experience by helping student’s
interaction with the subject content. Affordable 3d printers in schools may be used for a
various applications which can help students in finding their field of interest easier and
faster. Presently there are different types of educational projects in order to attract
students to the various fields by giving them the opportunity to create and manufacture

17. their own designs using 3d printing technology [23]
. 3D printing is the latest technology
making inroads into the classroom 3D printing allows students to create prototypes of
items without the use of expensive tooling required in subtractive methods. Students
design and produce actual models they can hold. The classroom environment allows
students to learn and employ new applications for 3D printing.
Students discover the capabilities with 3D printing. Engineering and design
principles are explored as well as architectural planning. Students recreate duplicates of
museum items such as fossils and historical artefacts for study in the classroom without
possibly damaging sensitive collections. Other students interested in graphic designing
can construct models with complex working parts. 3D printing gives students a new
perspective with topographic maps. Science students can study cross-sections of internal
organs of the human body and other biological specimens. And chemistry students can
explore 3D models of molecules and the relationship within chemical compounds.
6.3 CREATIVITY
The ability to develop and recent ideas is one of the most important needs in
the society and human development. Regarding this 3d printing can allow the creation of
complex geometries which are very difficult, costly or impossible to be manufactured
using conventional production methods [24]
.
6.4 Mass customization
Companies have created services where consumers can customize objects
using simplified web based customization software, and order the resulting items as 3D
printed unique objects. This now allows consumers to create custom cases for their
mobile phones. Nokia has released the 3D designs for its case so that owners can
customise their own case and have it 3D printed.
6.5 Communication
Employing additive layer technology offered by 3D printing, Terahertz devices
which act as waveguides, couplers and bends have been created. The complex shape of
these devices could not be achieved using conventional fabrication techniques.
Commercially available professional grade printer EDEN 260V was used to create

18. structures with minimum feature size of 100 µm. The printed structures were later DC
sputter coated with gold (or any other metal) to create a Terahertz Plasmonic Device.
6.6 Automobiles
In early 2014, the Swedish supercar manufacturer, Koenigsegg, announced the
One:1, a supercar that utilizes many components that were 3D printed. In the limited run
of vehicles Koenigsegg produces, the One:1 has side-mirror internals, air ducts, titanium
exhaust components, and even complete turbocharger assembles that have been 3D
printed as part of the manufacturing process.6.7 Firearms
In 2012, the US-based group Defense Distributed disclosed plans to "[design] a
working plastic gun that could be downloaded and reproduced by anybody with a 3D
printer." Defense Distributed has also designed a 3D printable AR-15 type rifle lower
receiver (capable of lasting more than 650 rounds) and a 30 round M16 magazine. The
AR-15 has multiple receivers (both an upper and lower receiver), but the legally-
controlled part is the one that is serialised (the lower, in the AR-15's case). Soon after
Defense Distributed succeeded in designing the first working blueprint to produce a
plastic gun with a 3D printer in May 2013, the United States Department of State
demanded that they remove the instructions from their website. After Defense Distributed
released their plans, questions were raised regarding the effects that 3D printing and
widespread consumer-level CNC machining may have on gun control effectiveness.
6.8 Apparel
3D printing has spread into the world of clothing with fashion designers
experimenting with 3D-printed shoes, and dresses. 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). The on demand customization market for glasses is something that has been
deemed possible with rapid prototyping.
6.9 Domestic use

19. As of 2012, domestic 3D printing had mainly captivated hobbyists and
enthusiasts and had not quite gained recognition for practical household applications. A
working clock was made and gears were printed for home woodworking machines among
other purposes. 3D printing was also used for ornamental objects. Web sites associated
with home 3D printing tended to include backscratchers, coathooks, doorknobs etc.
6.10 Rapid prototyping
Industrial 3D printers have existed since the early 1980s and have been used
extensively for rapid prototyping and research purposes. These are generally larger
machines that use proprietary powdered metals, casting media (e.g. sand), plastics, paper
or cartridges, and are used for rapid prototyping by universities and commercial
companies.
6.11 Medicine
3D printing has been used to print patient specific implant and device for medical
use. Successful operations include a titanium pelvis implanted into a British patient,
titanium lower jaw transplanted to a Dutch patient, and a plastic tracheal splint for an
American infant. The hearing aid and dental industries are expected to be the biggest area
of future development using the custom 3D printing technology. In 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. Research is also being conducted on methods to bio-
print replacements for lost tissue due to arthritis and cancer.
Printed prosthetics have been used in rehabilitation of crippled animals. In 2013, a
3D printed foot let a crippled duckling walk again. In 2014 a chihuahua born without
front legs was fitted with a harness and wheels created with a 3D printer. 3D printed
hermit crab shells let hermit crabs inhabit a new style home.
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 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. The first production system for 3D
tissue printing was delivered in 2009, based on NovoGen bioprinting technology. Several
terms have been used to refer to this field of research: organ printing, bio-printing, body

20. part printing, and computer-aided tissue engineering, among others. The possibility of
using 3D tissue printing to create soft tissue architectures for reconstructive surgery is
also being explored.
In 2013, Chinese scientists began printing ears, livers and kidneys, with living
tissue. Researchers in China have been able to successfully print human organs using
specialised 3D bio printers that use living cells instead of plastic. Researchers at
Hangzhou Dianzi University actually went as far as inventing their own 3D printer for the
complex task, dubbed the "Regenovo" which is a "3D bio printer." Xu Mingen,
Regenovo's developer, said that it takes the printer under an hour to produce either a mini
liver sample or a four to five inch ear cartilage sample. Xu also predicted that fully
functional printed organs may be possible within the next ten to twenty years. In the same
year, researchers at the University of Hasselt, in Belgium had successfully printed a new
jawbone for an 83-year-old Belgian woman. The woman is now able to chew, speak and
breathe normally again after a machine printed her a new jawbone.

21. 7. ADVANTAGES
ÿ Rapid Prototyping: 3D printing gives designers the ability to quickly turn
concepts into 3D models or prototypes (rapid prototyping).
ÿ Clean process: Wastage of material is negligible.
ÿ Complex shape can be produced easily.
ÿ Easy to use : No skilled person needed.
ÿ Reduce design complexity.
ÿ Cheap: Cheaper process than any other process.
8. DISADVANTAGES
ÿ Manufacture of Dangerous Items: The ability to print dangerous objects
such as plastic guns, knives, or any other object that could be used as a weapon.
ÿ Size Limitations: 3D printers have limitations when it comes to large size
of the objects created.
ÿ Scan & Fraud: 3D printers can be used to scan and print I.D. and credit
cards, car keys, as well as a multiplicity of other private belongings.
ÿ Raw Material Limitations: 3D printing is viable for items made from a
single raw material only.

22. 9. FUTURE 3D PRINTING APPLICATIONS
3d printers have many promising areas of potential future application. For
example, be used to output spare parts for all method of products, and which could not
may be stocked as part of the inventory of even the best physical store. Hence, rather than
fling away a broken item (something unlikely to be justified a decade or two hence due
to resource depletion and enforced recycling), imperfects goods will be able to be taken to
a local facility that will call up the appropriate extra parts online and simply print them
out. NASA has already trial a 3D printer on the International Space Station, and recently
declare its requirement for a higher resolution 3D printer to produce spacecraft parts
during deep space missions. The US Army has also investigated with a truck-mounted 3D
printer capable of outputting extra tank and other vehicle components in an area of
conflict.
The 3D printer has advanced from its reliance on plastic material, as it now can
print in metals and even organic material. Printers employing various types of 3D printing
methods can now print in plastics, metals, ceramics, enzymes, and biological cells [11].
With the staggering pace at which 3D printing is advancing, it would not be surprising if
the actual 3D printing of a human organ was possible. With the capability to advance all
fields of science and technology, 3D printing is only constrained by the depth of human
creativity.
3d printers may also be used to make future structure. To this end, a team at
Loughborough University is working on a 3d concrete printing plan, that could allow
large building elements to be 3d printed on-site to any model, and with amend thermal
properties.
Another possible future of 3d printers is to create replacement organs for the
human body. This is called as bioprinting and is an area of rapid development [25]
.

23. CONCLUSION
3d Printing technology could revolutionize and change the world. 3d printing
technology can consequential change and improve the way we manufacture products and
produce goods products. A target is scanned or designed with CAD software, then sliced
up into thin layers, then printed out to form a solid 3d product. The importance of an
invention can be appraised by determining which of the human needs it fulfills. 3D
printing can have an application in almost all of the categories of human needs. It will
provide companies and individuals fast and easy manufacturing in any size or scale
limited only by their imagination. The main advantage of the industrialization revolution
was that parts could be made nearly identically which meant they could be easily replaced
without individual tailoring. 3d printing can enable fast, reliable, and repeatable means of
producing products which can still be made inexpensively due to automation of processes
and distribution of manufacturing needs. Digital 3d printing revolution could bring mass
manufacturing back a full circle - to an era of future printing.

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[10] Frick, Lindsey. Aluminum-powder DMLS-printed part finishes race first.
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[20] http://www.chocedge.com
[21] Lipton, J., et al, Multi-Material food printing whith complex internal
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