Technology of additive manufacturing, 3-D printing and rapid prototyping

1. KRISHNA INSTITUTE OF ENGINEERING AND
TECHNOLOGY, GHAZIABAD
Seminar on
“ADDITIVE MANUFACTURING”
Submitted by: Submitted to:
Harsh Kumar Mr. Arunesh Chandra
Roll No.- 1202940074 ME Dept.
Sec. A , ME(3rd
year)

2. CONTENTS
1. History
2. Introduction
3. Additive manufacturing techniques
4. Advantages
5. Disadvantages
6. Applications
7. Scope of additive manufacturing
8. References

3. HISTORY
The technology for printing physical 3D objects from digital data was first
developed by Charles Hull in 1984. He named the technique stereolithography
and obtained a patent for the technique in 1986. The same year, he founded 3D
Systems and developed the first commercial 3D Printing machine.
AM processes for metal sintering or melting (such as selective laser
sintering, direct metal laser sintering, and selective laser melting) usually went
by their own individual names in the 1980s and 1990s. Nearly all metalworking
production at the time was by casting, fabrication, stamping, and machining; even
though plenty of automation was applied to those technologies (such as by robot
welding and CNC), the idea of a tool or head moving through a 3D work envelope
transforming a mass of raw material into a desired shape layer by layer was
associated by most people only with processes that removed metal (rather than
adding it), such as CNC milling, CNC EDM, and many others.
Charles Hull

4. INTRODUCTION
The process of joining materials to make objects from 3D model data,
usually layer upon layer, as opposed to subtractive manufacturing methodologies
is known as Additive Manufacturing.
Synonyms: additive fabrication, additive processes, additive techniques,
additive layer manufacturing, layer manufacturing and freeform fabrication.
As an Enabling Technology AM is used in a broad spectrum of manufacturing.
Illustration of this process

5. Steps For Additive Manufacturing
1. Generate a 3D model
Draw a 3D model of product on any software such as CAD,
Solid Works etc.
2. Generation of STL(Stereolithography) file
The STL (stereo lithography) file format is supported by many
other software packages; it is widely used for rapid prototyping and computer-
aided manufacturing (CAM). STL files describe only the surface geometry of
a three dimensional object without any representation of color, texture or other
common CAD model attributes.
*An STL file describes a raw unstructured triangulated surface by the unit
normal and vertices (ordered by the right-hand rule) of the triangles using a
three-dimensional Cartesian coordinate system.
Fig. STL File

6. 3. Software slices the 3D model into thin slices
Fig. Slicing of 3D model
Now computer scans this area and give instructions to printer or
machine to procced for further operations.
4. Machine builds it layer by layer
5. Cleanup and post curing
6. Surface finishing

7. Additive Manufacturing technologies and their base materials :
1. 3D Printing (3DP): Various materials, including resins
2. 3D Ceramic Printing: Various clay and ceramic materials
3. Selective laser sintering (SLS): Thermoplastics, metals, sand and glass
4. Fused Deposition Modeling (FDM): Thermoplastics
5. Stereolithography (SL): Photopolymer
6. Laminated object manufacturing(LOM): Laminate sheets, often paper, and
glue
7. Electron Beam Melting (EBM): Titanium alloys
Machine Cost Response Time Material Application
Fused Deposition
Modeler 1600 (FDM)
$10/hr 2 weeks ABS or Casting
Wax
Strong Parts
Casting Patterns
Laminated Object
Manufacturing
(LOM)
$18/hr 1 week Paper (wood-
like)
Larger Parts
Concept Models
Sanders Model
Maker 2 (Jet)
$3.30/hr 5 weeks Wax Casting Pattern

8. Selective Laser
Sintering 2000 (SLS)
$44/hr 1 week Polycarbonate
TrueForm
SandForm
light: 100%; margin:
0">Casting Patterns
Concept Models
Stereolithography
250 (SLA)
$33/hr 2 weeks Epoxy Resin
(Translucent)
Thin walls
Durable Models
Z402 3-D Modeller
(Jet)
$27.50/hr 1 week Starch/Wax Concept Models
1. Selective laser sintering (SLS)
This is an additive manufacturing technique that uses a high power laser
to fuse small particles of plastic, metal, ceramic or glass powder into the
desired 3-D shape.
The laser selectively fuses the material by scanning cross sections
generated from a 3-D digital description of the part, for example a CAD file.
It can be used for both thermoplastics and metal. Powder is fed into a
continuous layer. Laser is used to fuse/sinter powder particles layer-by-layer.
Produces functional parts. Layer thickness 0.004” or less.

9. Fig. SLS Manufacturing Technique
SLS Samples:
A Basket A complex model

10. 2. Electronic beam melting (EBM)
This solid freeform fabrication method produces fully dense meta, parts
directly from metal powder. The EMB machine reads data from a 3-D CAD
model and lays down successive layers of powdered material. The layers are
melted together with the help of a computer controlled electron beam. This
way it builds up the parts. The process takes place under a vacuum, which
makes it suited to manufacture parts made out of reactive materials
• Dispensed metal powder in layers
• Cross-section molten in a high vacuum with a focused electron beam
• Process repeated until part is completed
• Stainless steel, Titanium, Tungsten parts
• Ideal for medical implants and injection molds
• Still very expensive process
Fig. EBM manufacturing technique

11. EBM samples:

12. 3. 3D Printing(3DP)
Fig. 3D Printing technology
• Layer of powder is first spread across build area
• Inkjet-like printing of binder over the part cross-section
• Repetition of the process with the next layer
• Can produce multi-colored parts
• Useful only for presentation media
• Lowest resolution of all techniques
• Market Leader: Z-Corp

13. 3D Printing samples:
Piston with cam-follower Morongo Casino, Palm Springs, Model
4. Fused deposition modelling (FDM)
FDM works on an "additive" principle by laying down material in
layers. A plastic filament or metal wire is unwound from a coil and supplies
material to an extrusion nozzle. The nozzle is heated to melt the material
and can be moved horizontally and vertically. The part, or model, is
produced by extruding mall beads of thermoplastic material to form layers
and the material hardens immediately after extrusion from the nozzle.
• Extruder on a cartesian robot
• Extrudes thermoplast polymers “spaghetti”
• Moderately fast and inexpensive
• Stratasys is the market leader
• Functional parts, ABS and nylon
• Best choice for mechanical engineers and product developers
• Can be used for direct digital manufacturing

14. • Systems starting from $14,000
Fig. FDM manufacturing technique
FDM samples
Internal gear
A Model

15. 5. Laminated Object Modeling (LOM)
In some printers, paper can be used as the build material, resulting in a
lower cost to print. During the 1990s some companies marketed printers that cut
cross sections out of special adhesive coated paper using a carbon dioxide laser
and then laminated them together. In 2005 Mcor Technologies Ltd developed a
different process using ordinary sheets of office paper, a tungsten carbide blade
to cut the shape, and selective deposition of adhesive and pressure to bond the
prototype. There are also a number of companies selling printers that print
laminated objects using thin plastic and metal sheets.
• Object made by deposition and cutting of layers of tapes
• Introduced in 1991 by Helisys Inc of Torrance.
• Cubic and Helisys offer this technology
• Slow, sharp edges
• Research on composites prepregnated moldless manufacturing
• Inexpensive depending on accuracy, large scale models possible
• Slow and inaccurate (knives vs lasers)

16. Fig. LOM manufacturing technique
LOM samples
Fig. 1- parts made up of plastics
2-model made up of paper
3-model made up of paper

17. 6. Stereolithography (SLA)
Stereolithography is a process for creating three-dimensional objects
using a computer-controlled laser to build the required structure, layer by layer.
It does this by using a resin known as liquid photopolymer that hardens when in
contact with the air.
• Patented in 1986
• 3D System is the market leader
• Highest resolution and smoothness
• UV Laser beam cure cross-sections of parts in a liquid batch of
photoreactive resin
• Subvariants: DLP entire layer projection
Fig. SLA manufacturing technique

18. SLA samples
An aeroplane model Nokia Lumia 820 Case
ADVANTAGES OF ADDITIVE MANUFACTURING
 Adopted 3D printing as a way to increase innovation.
 Mechanical properties of products are more as compared to that which are
made by conventional process.
 Reduce costs and speed up the process.
 3D models of buildings can be easily created and edited as plans develop
something that used to take a significant amount of time to make.
 Freedom of creation of more complex geometries.
 More Complex Geometries
 Internal Features & Structures
 Parts Consolidation

19.  Enables business models used for 2D printing, such as for photographs, to
be applied to physical components
Fig. 2D Printing
 The unattainable triangle of speed, price and quality.
 Eliminates drivers to concentrate production
 “Design Anywhere / Manufacture Anywhere” is now possible
 Manufacture at the point of need rather than at lowest labor
location
 Changing “Just-in-Time Delivery” to “Manufactured-on-
Location Just-in-Time”
DISADVANTAGES OF ADDITIVE MANUFACTURING
 Construction of large parts is not possible but research are going to make
large machines.
 Machine cost is high
 The current slow print speed of 3D printers limits their use for mass
production.

20. APPLICATIONS OF ADDITIVE MANUFACTURING
 Medical procedures
 Advances in research
 Product prototyping
 Historic Preservation
 Architectural Engineering Construction
 Advanced Manufacturing
 Food Industries
 Automotive
 Accessories

21. 1. Architectural Engineering Construction
Morongo Casino, Palm Springs, Model
Morongo Casino, Palm Springs
2. Automotive
Fig. Engine model Fig. Tyre rim

22. 3. Medical procedures
Bespoke Entire titanium jaw
SCOPE OF ADDITIVE MANUFACTURING

23.  First ever 3-D printed car.
 Urbee is the first prototype car ever to have its entire body 3D printed with
an additive process. All exterior components, including the glass panel
prototypes, were created using Dimension 3D Printers and Fortus 3D
Production Systems at Stratasys' digital manufacturing service.
Fig. URBEE- First 3D printed car
 3-D printed Buildings?
 Architect Enrico Dini is planning to build the first ever 3-D printed
building with the help of fellow architects.

24. REFERENCES
 Professor John Hart(ajhart@mit.edu), Massachusetts Institute Of
Technology(MIT)
 Wright, Paul K. (2001). 21st Century manufacturing. New Jersey:
Prentice-Hall Inc.
 Lipson, Hod, Francis C. Moon, Jimmy Hai, and Carlo Paventi. (2007)
"3D-Printing the History of Mechanisms." Journal of Science.