3D Printing

ABSTRACT
Three-dimensional printing, also known as additive manufacturing, is the process of using
additives to form solid 3D objects of virtually any shape from a digital model. This is
achieved using specially formulated additives, such as plastics, that are formed into
successive layers of material typically laid down on a platform in different shapes. The first
published account of a printed solid model was made by Hideo Kodama of Nagoya Municipal
Industrial Research Institute in 1982. The first working 3D printer was created in 1984 by
Charles W. Hull of 3D Systems Corp. Of course, 3D printing in the early days was very
expensive and not feasible for the general market. As we moved into the 21st century,
however, costs drastically dropped, allowing 3D printers to find their way to a more
affordable market. With the introduction of 3D printing technology, you can go for a mass
production. You can increase the production with less capital as they will be controlled by the
same controller. Medical science is also taking the help of this technique. According to these
futurists, 3-D printing will make life as we know it today barely recognizable in 50 to 75
years. "Realistically, we're going to be living to 100 -110. With bio-printed organs, living to
110 won't be anything like living to that age today," contends Jack Uldrich, a technology trend
expert. "We're already printing skin, kidneys, a replica of a beating human heart. If a person
loses a limb, we'll be able to print, layer by layer, a replacement. It's theoretically
possible."There are many companies that offer 3D services to consumers. They need to
upload their design in the website and your design will be ready within a few hours. Just
imagine you can print a solid object from a device connected to the computer. It sounds like a
world of star trek.

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1.Introduction to 3D Printing
As every designer knows, theres magic in transforming a great idea into a tangible and useful
object you can hold in your hand. It can be a consumer good on a store shelf, a critical
component of an industrial machine, or even an early physical prototype that unveils your
new idea to the world.
Physical prototypes basic and blocky or wonderfully realized in shape, texture and color
go far beyond drawings or computer models to communicate your vision in a dramatic
way. They empower the observer to investigate the product and interact with it rather than
simply guess what it might be like. Before the product is ever produced, people can touch it;
feel it; turn it left, right and upside down; and look inside. They can test it, operate it and fully
evaluate it long before the finished product is brought to market.
Until recently, a quick and affordable physical prototype has been an oxymoron. Obtaining
prototypes wasnt quick. It meant contracting with a fabricator who handcrafted them or used
a complicated stereo lithography machine. In either case, it took weeks, and it wasnt
affordable. You were billed thousands of dollars for your trouble.
And who needs just one prototype? Successful product developers revise a design repeatedly
until they approach their ideal. Physical prototypes available on demand in sample quantities
accelerate the design process, and more quickly send a better product to market.
This ideal is in fact a reality for some of the worlds most accomplished and demanding
designers and engineers. Available within a couple of hours of hitting print on a quiet, clean
and sleek machine in an everyday office setting, on-demand prototypes today help
engineering organizations:

improve communication within the product development organization;

shorten design cycles

put superior products on the market ahead of the competition

stretch R&D dollars

improve accuracy

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eliminate costly mistakes

trigger unexpected ideas

drive innovation and quality

Improve collaboration among engineering, sales, marketing and the executive team.

This paper will cover the inception and evolution of 3D printing; then explore in depth how a
3D printer produces a physical model; and finally, examine the defining attributes of a 3D
printer and the technology decisions that produced them.

1.1 What is 3D PRINTER?

3D printing or additive manufacturing (AM) is any of various processes for making a
three-dimensional object of almost any shape from a 3D model or other electronic data source
primarily through additive processes in which successive layers of material are laid down
under computer control
3D Printers are machines that produce physical 3D models from digital data by printing layer
by layer. It can make physical models of objects either designed with a CAD program or
scanned with a 3D Scanner. It is used in a variety of industries including jewelry, footwear,
industrial design, architecture, engineering and construction, automotive, aerospace, dental
and medical industries, education and consumer products.

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2. History of 3d Printing
The technology for printing physical 3D objects from digital data was first developed by
Charles Hull in 1984. He named the technique as Stereo lithography and obtained a patent for
the technique in 1986.
While Stereo lithography systems had become popular by the end of 1980s, other similar
technologies such as Fused Deposition Modeling (FDM) and Selective
Laser Sintering (SLS) were introduced.
In 1993, Massachusetts Institute of Technology (MIT) patented another technology, named "3
Dimensional Printing techniques", which is similar to the inkjet technology used in 2D
Printers.
In 1996, three major products, "Genisys" from Stratasys, "Actua 2100" from 3D
Systems and "Z402" from Z Corporation were introduced. In 2005, Z Corp. launched a
breakthrough product, named Spectrum Z510, which was the first high definition color 3D
Printer in the market.
Another breakthrough in 3D Printing occurred in 2006 with the initiation of an open source
project, named Reprap, which was aimed at developing a self-replicating 3D printer.

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3. Current 3D Printing Technologies

3.1 Stereo lithography
Stereo lithographic 3D printers (known as SLAs or stereo lithography apparatus) position a
perforated platform just below the surface of a vat of liquid photo curable polymer. A UV
laser beam then traces the first slice of an object on the surface of this liquid, causing a very
thin layer of photopolymer to harden. The perforated platform is then lowered very slightly
and another slice is traced out and hardened by the laser. Another slice is then created, and
then another, until a complete object has been printed and can be removed from the vat of
photopolymer, drained of excess liquid, and cured.
Fused deposition modeling - Here a hot thermoplastic is extruded from a temperaturecontrolled print head to produce fairly robust objects to a high degree of accuracy.

3.2 Selective laser sintering (SLS)

This builds objects by using a laser to selectively fuse together successive layers of a cocktail
of powdered wax, ceramic, metal, nylon or one of a range of other materials.

3.3 Multi-jet modeling (MJM)

This again builds up objects from successive layers of powder, with an inkjet-like print head
used to spray on a binder solution that glues only the required granules together. The V-Flash
printer, manufactured by Canon, is low-cost 3D printer. Its known to build layers with a
light-curable film. Unlike other printers, the VFlash builds its parts from the top down.
Desktop Factory is a startup launched by the Idea lab incubator in Pasadena, California.

3.4 Fab@home
It is an experimental project based at Cornell University, uses a syringe to deposit material in
a manner similar to FDM. The Inexpensive syringe makes it easy to experiment with different
materials from glues to cake frosting.

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3.5 Inkjet 3D printing

It creates the model one layer at a time by spreading a layer of powder (plaster, or resins) and
inkjet printing binder in the cross-section of the part. It is the most widely used 3-D Printing
technology these days and the reasons beyond that are stated below.
This technology is the only one that

Allows for the printing of full color prototypes.

Unlike stereo lithography, inkjet 3D printing is optimized for speed, low cost, and easeof-use.

No toxic chemicals like those used in stereo lithography are required.

Minimal post printing finish work is needed; one needs only to use the printer itself to
blow off surrounding powder after the printing process.

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4. MANUFACTURING A MODEL WITH THE 3D

PRINTER
To set up this new process, two steps are necessary: the amount of the printed material must
be reduced to a minimum, and the dosed material mustnt be a part of the desired object.
This will be achieved by separation of the process in information transfer and material
deposition. The minimum information to create the cross section of an object is the boundary
line. This outline will be printed by means of a droplet generator. Thus a thin shell of the
model will be formed. For example, the shell material could be a release wax with a high
melting point. In the next step the layer is filled with building material by a rapid application.
This material could be also wax with a lower melting point or a fast curing resin etc.

Figure shows the new printing method for making a three-dimensional body:

Figure 4: 3D Printing Process

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The repeated steps are:

1) Lowering the platform according to the layer thickness.
2) Applying a release wax in its liquid state onto selected areas of a building platform by
a multi-jet printhead, using a pattern according to the cross-section of a thin-walled
shell around the three-dimensional body, and a grid pattern (not shown in Figure 1)
across the remaining area of the building platform.
3) After finishing of the pattern of the current layer, the areas enclosed by the release wax
are filled with the building wax.
4) Smoothing and planing of the layer in order to expose the upper surface of the release
wax.
5) Ready for the next layer. Repetition of the steps 1) to 4) with patterns according to the
current cross-section of the three-dimensional body, thereby making the body itself.
6) Removing the structures not belonging to the body by dissolving the release wax.

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5. WORK FLOW OF 3D PRINTING

The workflow can be easily understood with the help of the flowchart given below.
A 3-D prototype of a desired object is created in three basic steps and these steps are:

Pre-Process

3-D Printing

Post-Process

FIGURE 5.1 Process of 3D Printing

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5.1 CAD Preparation (Pre-Process):

Computer-aided design (CAD), also known as computer-aided design and drafting
(CADD), is used to prepare a 3-D or 2-D model of the desired object. Modern CAD
packages can also frequently allow rotations in three dimensions, allowing viewing of a
designed object from any desired angle.
Most 3D printers require a special file (typically .stl format) to print. Additionally, we need
to modify the design to make up for limitations of the printer and build material.

FIGURE 5.1 Pre-Process of 3D Printing

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5.2 3D Printing:
The 3D printer runs automatically, depositing materials at layers ~.003 thick. This is
roughly the thickness of a human hair or sheet of paper. The time it takes to print a given
object depends primarily on the height of the design, but most designs take a minimum of
several hours. The average cost for printing a full color prototype is somewhere between
50 - 100$.

FIGURE 5.2 Printing an Object

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5.3 Cleaning 3D Printouts (Post-Process):

Every 3D printer uses some sort of material to support parts of the design that have an
overhang. Some printers use a loose powder which can be blown off and reused in future
models.

FIGURE 5.3 Post-Process of 3D Printing

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5.3.1 Powder Removal:

This is the sculpture with most of the support dust removed and it is then dipped in special
glue that makes them stronger and more colorful.

FIGURE 5.3.1 Powder Removal

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5.3.2 Heating
The models are heated to set the glue. It is funny to see the oven in this picture is a
standard consumer grade.

FIGURE 5.3.2 Heating

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5.3.3 Finishing Touches

The output of all existing 3D printers is rough. The textures vary from pronounced wood
grain to merely sandy, With a little elbow grease you can get stunning results.

FIGURE 5.3.3 Final Touch up

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6. Benefits of 3D Printing

The most successful companies have adopted 3D printing as a critical part of the iterative
design process to:
Increase Innovation
Print prototypes in hours, obtain feedback, refine designs and repeat the cycle until
designs are perfect.
Improve Communication

Hold a full color, realistic 3D model in your hands to impart infinitely more
information than a computer image.

Create physical 3D models quickly, easily and affordably for a wide variety of
applications.

Speed Time to Market

Compress design cycles by 3D printing multiple prototypes on demand, right in

your office.

Reduce Development Costs

Cut traditional prototyping and tooling costs.

Identify design errors earlier.

Reduce travel to production facilities.

Win Business

Bring realistic 3D models to prospective accounts, sponsors and focus groups

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7. Applications

7.1 Design Prototypes:

3-Dimensional Printing concept model, functional prototypes and presentation

models for evaluating and refining design, including Finite Element Analysis
(FEA) results and packaging.

Size: 3.5 x 2 x 0.7 inches

(9 x 5 x 2 cm)

Printing Time: 0.5 hours

Now, here we have

Nokia mobile phone for
demonstration:

created a dummy of a
further study and

FIGURE 7.1 Demo Model

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7.2 Education:

Engage students by bringing digital concepts into the real world, turning their ideas
into real-life 3D color models that they can actually hold in their hands.

Here an electronic device circuit has come to life with the help of a 3-D Printer:

Size: 8 x 5 x 2.5 inches

(20 x 13 x 6 cm)

Printing Time: 3 hours

FIGURE 7.2 an electronic device circuit Created by 3D Printer

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7.3 Healthcare:

Rapidly produce 3D models to reduce operating time, enhance patient and

physician communications, and improve patient outcomes.

A 3-D Prototype of the horizontal crossection of a human skull has been prepared to allow
its better study:

Size: 9.8 x 7.9 x 3.9 inches

(25 x 20 x 10 cm)

Printing Time: 5.5 hours

FIGURE 7.2 3-D Prototype of a human skull

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8. Conclusion
Nothing communicates ideas faster than a three-dimensional part or model. With a 3D
printer you can bring CAD files and design ideas to life right from your desktop. Test
form, fit and function and as many design variations as you like with functional parts. In
an age in which the news, books, music, video and even our communities are all the
subjects of digital dematerialization, the development and application of 3D printing
reminds us that human beings have both a physical and a psychological need to keep at
least one foot in the real world. 3D printing has a bright future, not least in rapid
prototyping, but also in medicine the arts, and outer space. Desktop 3D printers for the
home are already a reality if you are prepared to pay for one and/or build one yourself. 3D
printers capable of outputting in color and multiple materials also exist and will continue
to improve to a point where functional products will be able to be output. As devices that
will provide a solid bridge between cyberspace and the physical world, and as an
important manifestation of the Second Digital Revolution, 3D printing is therefore likely
to play some part in all of our futures.

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9.REFRENCES
[1]en.wikipedia.org/wiki/3D_printing.
[2]http://www.newscientist.com/article/mg21128236.100-3d-printing-the-technologythat-changes-everything.html
[3] http://www.stratasys.com/3d-printers/design-series/dimension-1200es
[4] http://replicatorinc.com/blog/2008/12/a-major-advance-in-3d-printing

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