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

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.

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].

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.

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.

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].

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.

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.

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].

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].

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

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

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:

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

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.

[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

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

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

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

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.

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.

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].

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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