Richard Wysk, North Carolina State University - Speaker at the marcus evans Manufacturing COO Summit 2012, held in Las Vegas, NV, April 16-17, 2012, delivered his presentation entitled Broad Considerations for Sustainable Engineering

1. Some broad considerations for
sustainable engineering
i bl i i
Richard A. Wysk
Dopaco Distinguished Professor
Industrial and Systems Engineering
y g g
North Carolina State University
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2. Agenda
• Sustainability ‐‐ a brief overview
• Sustainability from an engineering perspective
Sustainability from an engineering perspective
– This could be the world’s most difficult
engineering problem
g gp
• What’s new in the manufacturing world?
– Direct manufacturing (DM) and hybrid
Direct manufacturing (DM) and hybrid
manufacturing (HM)
• New directions in DM, HM and sustainability
y
• Observations and conclusions
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3. Why Engineer for Sustainability?
Why Engineer for Sustainability?
• Should be considered as part of a concurrent
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engineering team effort.
• 80% of the environmental damage of a product is
established after 20% of the design activity is
bl h d f f h d
complete.
• Business case analysis
Business case analysis
– Customers demand products with less environmental
impact,
• Governmental agencies are developing and enforcing
tighter regulations.

4. Pay me now or pay me later
Pay me now or pay me later

5. A Vision of Sustainable Engineering
Systems

6. Environmental Objectives
Environmental Objectives
• Protect the biosphere
Protect the biosphere
– Minimize the release of pollutants that endanger the
earth.
• Sustainable use of resources
– Use raw materials at a level where they can be
sustained.
• Reduction and disposal of waste
– Minimize waste wherever possible. When waste
cannot be avoided, recycling will be adopted.

7. Environmental Objectives
Environmental Objectives
• Wise use of energy
Wise use of energy
– Use environmentally safe energy and invest in
energy conservation.
energy conservation
• Risk reduction
– Minimize health risk to employees and the
Minimize health risk to employees and the
community.
• Marketing of safe products and services
Marketing of safe products and services
– Sell products that minimize environmental
impact and are safe for consumers to use.

8. Life Cycle Assessment
Life Cycle Assessment
• Common methodology
Common methodology
– Society of Toxicology and Chemistry (SETAC) has
developed a 4 step process for completing a Life
developed a 4‐step process for completing a Life
Cycle Assessment (LCA).
• Cradle to grave assessment.
• Dependent on large amounts of data.
• Steps: Goal Definition, Environmental Impact Inventory,
Impact Assessment, Interpretation.

9. What Is Life‐Cycle Assessment (LCA)?
LCA i a analytical f
is l ti l framework used t examine, id tif and
k d to i identify, d
evaluate the energy, resource, and environmental implications
of a process, product, or system across its life span from
cradle to grave.
Linear View of Products
Raw Material Acquisition and Processing
Raw Material Acquisition and Processing
Manufacturing
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Use
Disposal
Source: EPA (2006) – LCA: Principles and Practice Courtesy of Ranji Ranjithan

10. Inventory Analysis
Inventory Scope Inventory
Product Life Stages
Primary Airborne
Materials Raw Material Acquisition and Processing Emissions
Manufacturing
Secondary Waterborne
Materials
M i l Emissions
E i i
Recycling
Reuse
Use
Energy Other
End of Life Management Releases
Use a SCOR Model to determine how this works in a
Courtesy of Ranji Ranjithan PLAN,SOURCE, MAKE, DELIVER, and RETURN environment

11. Techniques to Reduce Environmental Impact
q p
Design to minimize material usage
• Material usage
– Packaging and distribution
• Programs to accept back packaging (computers)
– Production system
• Ex.: plastic body panels (Chrysler) that require no paint
( )
– Product
• Minimize “high impact” materials
Minimize high impact materials
• Increase use of materials that can be processed together
• Can different polymers be remelted together (e.g.
compatibility)?

12. Techniques to Reduce Environmental Impact
Techniques to Reduce Environmental Impact
Design for Disassembly
• Guidelines similar to DFA.
• Some key differences:
Some key differences:
– Snap‐fit design (integral fasteners) must work
during removal as well as insertion should a part
during removal as well as insertion should a part
be needed for remanufacturing.
– For recycling only “tearing apart” is of interest.
– Must consider ergonomics and time. Disassembly
time may be very different than assembly time.

13. Techniques to Reduce Environmental Impact
Techniques to Reduce Environmental Impact
Design to Recycling
• Primarily material choice. Recycling Rate (%)
• Typical materials recycled in US 1993 2006
– High density polyethylene (HDPE) 10.6 26
– Polyethylene terephthalate (PET) 18.0 24
– Low‐density polyethylene (LDPE) 1.9 1
– Polypropylene (PP) 1.5 9
– Polyvinyl chloride (PVC) 0.8 1

14. Techniques to Reduce Environmental Impact
Techniques to Reduce Environmental Impact
Design to Recycling
• Other recycling:
– Gl (
Glass (can lower heat needed to melt)
l h t d dt lt)
– Metal chips
– Paper (ask McDonald’s!)
( k ld’ !)
• New technologies
– Chips or identifiers to automatically recycle (auto
industry)

15. Styrofoam A problem?!?
Styrofoam – A problem?!?

16. Short term answers
Short‐term answers
• Compacting reduces volume
Compacting reduces volume
• Doesn’t really eliminate the
problem

17. Techniques to Reduce Environmental Impact
New Technologies
N T h l i
Polystyrene Foam
Recycling System
Employing Limonene
Sony

18. Techniques to Reduce Environmental Impact
Techniques to Reduce Environmental Impact
Design to minimize hazardous materials
• Functionally equivalent materials can have
a large impact on the environment.
a large impact on the environment.
– Ex.: switch from using polystyrene to less‐
impacting plastics such as high density
polyethylene (recycled at much higher rate)
• No impact on design performance.
• Ch i l t
Chemicals to avoid
id
• Material impact comparisons
– Must also consider cost differences.

19. Techniques to Reduce Environmental Impact
Design for energy efficiency
• Reduce energy consumption of product
– Specify best‐in‐class energy efficient components (air
conditioners, refrigerators)
– Have subsystems power down when not in use (copiers)
– Permit users to turn off systems in part or whole
Permit users to turn off systems in part or whole
– Solar‐powered electronics (calculators)
– Vibration harvesting
– Insulate heated systems
y
– Make parts whose movement is powered as light as possible
(autos, planes)
• New materials and processes give many new opportunities
• Must be qualified and accepted; designers must understand how to
Must be qualified and accepted; designers must understand how to
design with them (“design rules”); may limit suppliers
• Buy to fly (Can be 200:1)
• 100 pounds can mean 2% in MPG

20. Supportability Considers Total System
“Cost of Ownership”
“ f h ”
Mike Battaglia; https://c3.nasa.gov/dashlink/static/media/other/Design4Supportability.pdf

21. Okay, so this has been going on for a
decade or more. What’s next?
d d h ’
• Changes in reclamation
• More efficient methods
• Changes in manufacturing
• New paradigms
• Changes in design
Changes in design
• Unconventional geometries
• Changes in materials
• Composites (higher strength to weight ratio)
Composites (higher strength to weight ratio)
• Up to 2% gas reduction per 100 pounds
• Materials usage efficiency
• 200:1 buy to fly ratio

22. Something very new
Something very new

23. A New Prosthetic Arm
A New Prosthetic Arm
• Titanium for
efficiency/medical
compatibility
• Mesh structure
• Weighs about 4
pounds
• Can change the life
of a limb amputee
p

24. Impossible to build without additive
methods
h d

25. Functional using mechanical switching
Functional using mechanical switching

26. Medical/Dental/
Veterinary Applications
V i A li i
March 24 2006 (Chicago) -- The number of
24,
total knee replacements performed in the
U.S. will leap by 673% -- reaching 3.48
million -- b th year 2030, according to a
illi by the 2030 di t
new study presented at the 73rd annual
meeting of the American Academy of
Orthopaedic Surgery in Chicago.
Hip replacements will increase by 174% to
572,000 by 2030, according to the new
findings, which are based on historical
procedure rates from 1990 to 2003, and on
d t f t 2003 d
population projections from the U.S. Census
Bureau.

27. Direct Manufacturing
Direct Manufacturing
• Producing a product directly
Producing a product directly
from a descriptive model.
– In the mechanical part domain
In the mechanical part domain,
taking a CAD model and directly
manufacturing a part
g p

28. Additive Manufacturing
• Direct Manufacturing (DM)
– Direct from CAD model without tooling
Direct from CAD model without tooling
• No process engineering
– Short lead time
– I
Increased product fidelity
d d t fid lit
– Ready to use end products
• Additive processes
Additive processes Painted SLA Consumer Goods Part
– Traditional Rapid prototyping (RP) process
• 3D printer, SLA, FDM, SLS, SLM, EBM…
– No geometry limitation
– Push button manner operation
– Restricted in material, accuracy, and surface finish
, y,
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29. Electron Beam Melting (EBM)
Electron Beam Melting (EBM)
• Electron Beam Melting (EBM) is a type of rapid
Electron Beam Melting (EBM) is a type of rapid
prototyping for metal parts. The technology
manufactures parts by melting metal powder layer
per layer with an electron beam in a high vacuum.
Unlike some metal sintering techniques, the parts
are fully solid, void‐free, and extremely strong.
Electron Beam Melting is also referred to as
Electron Beam Machining.
• High speed electrons .5‐.8 times the speed of light
are bombarded on the surface of the work material
b b d d th f f th k t i l
generating enough heat to melt the surface of the
part and cause the material to locally vaporize.
EBM does require a vacuum, meaning that the
workpiece is limited in size to the vacuum used.
is limited in size to the vacuum used.
The surface finish on the part is much better than
that of other manufacturing processes. EBM can be
used on metals, non‐metals, ceramics, and
composites.

30. Current directions in Manufacturing
Current directions in Manufacturing
– Additive Manufacturing
Selective Laser
Selective Laser
Electron Beam Melting Processes
Melting (EBM) (SLM) 30

31. Some other EBM parts
Some other EBM parts
31

32. EBM and Selective Laser Melting (SLM)
EBM and Selective Laser Melting (SLM)
• Produces parts to about
casting quality directly from a
CAD model
• Does not have the geometric
limitations of casting
limitations of casting
– Draft, parting line, etc.
• Materials properties are
Materials properties are
getting close to cast quality
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33. State of the Art for AM
State of the Art for AM
• Push bottom process – no process engineering
Push bottom process no process engineering
component
• Functional metals are now being produced
Functional metals are now being produced
• Net‐shape or near net‐shape parts can be
produced
d d
• Geometrically few limits, except for precision
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34. Recent directions in Rapid
Manufacturing ‐‐ Subtractive
CNC‐RP Method: A model is machined on a 3‐Axis mill with an
CNC RP Method: A model is machined on a 3 Axis mill with an
indexer and tailstock using layer‐based toolpaths from numerous
orientations about an axis of rotation.
Small diameter flat‐end mill tool
Round stock, fixed
between chucks
b t h k
4th‐axis indexer
Tailstock
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35. CNC RP Methodology
CNC‐RP Methodology
STEPS TO CREATE A PART ( MT. Bike Suspension Component)
(Side View)
1. First orientation of part section is machined 3. Third o e a o is machined
3 d orientation s ac ed
Rotate Stock
2. Second orientation is machined 4. Fourth orientation is machined
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36. CNC‐RP Methodology
STEPS TO CREATE A PART ( MT. Bike Suspension Component)
5. Left support section is machined 7. Temporary supports are removed
8. Part is severed from stock at supports
6. Right support section is machined
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37. CNC RP Methodology
CNC RP Methodology
• Creation of complex parts using a series of thin layers
(slices) of 3‐axis toolpaths
( li ) f 3 i t l th generated at numerous
t d t
orientations rotated about an axis of the part
• Toolpath planning based on “layering” methods used by
other RP systems
• “Slice” represents visible cross‐sectional area to be
machined about (subtractive) rather than actual cross
machined about (subtractive) rather than actual cross
section to be deposited (additive)
• Slice thickness is the depth of cut for the 2½‐D toolpaths
• T l
Tool used is a flat end mill cutter with equal flute and
d i fl t d ill tt ith l fl t d
shank diameter (or shank diameter < flute diameter)
• Stock material will be cylindrical, therefore toolpath z‐zero
location will be same for all orientations
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38. Methodology (cont.)
Methodology (cont )
Flat end mill cutter
“Staircase” effect
Region not visible from
bl f
current orientation
Set of visible slices from
current orientation
Toolpath planning using this approach is done with ease in current CAM
Toolpath planning using this approach is done with ease in current CAM
software (MasterCAM rough surface pocketing)
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39. Fixture Planning
• Approach uses “sacrificial supports” to retain the prototype within the
stock material
• Round stock clamped between opposing chucks
• As prototype is rotated b/w toolpaths sacrificial supports are
incrementally created
• Supports cut away to remove finished part
• Current approach assumes model surfaces exist along axis of rotation
– Only one fixture support cylinder used on each end
– No change to visibility calculations
39

40. Some other CNC RP parts
Some other CNC‐RP parts
(e)
(f)
(a)
(d)
(b)
(g) (h)
(c)
40

41. A broad comparison
A broad comparison
Characteristic EBM Casting Machining CNC‐RP
Geometry
y Very good
yg Fair Good Good
Tolerance/SF Fair Fair Very Good Good
Energy Fair(Part specific) Very Good Very Good Good
Set up cost Very good Fair Fair (Part specific) Very good
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42. Is it possible to get the best of both additive and
subtractive manufacturing?
b i f i ?
A hybrid EBM and
CNC‐RP system
42

43. It would be nice to ..
It would be nice to ..
43

44. Zeus
• Zeus, a Siberian Husky
with a missing front paw
• First patient with front
limb amputation
• Different design needed
for the attachment

45. Combining Additive and Subtractive Processing
Combining Additive and Subtractive Processing
CAD model Part with CNC RM fixtures STL model for EBM RP process. EX:
with all sacrificial EBM
supports
CNC‐ RM Process Identify functional Part for CNC RP Part from RP
surfaces with supports process
Final part from
AIMS
45

46. EBM Methodology
EBM Methodology
46

47. And ..
And ..

48. So where is our future headed?
So where is our future headed?
• Design rules will change significantly
Design rules will change significantly
– We will not be limited to the use of solid
mechanical components for high performance
mechanical components for high performance
products
48

49. Our future …
Our future …
• Manufacturing cost and energy needs to be
Manufacturing cost and energy needs to be
viewed/justified using operational costs as
well as production cost
well as production cost
– Possibility of eliminating more than 50% of the
product weight
product weight

50. For instance
For instance
Magnus René, CEO of Arcam.
Magnus René CEO of Arcam
50

51. Non dense mesh parts
Non‐dense mesh parts
• Hi h h
Higher shear parts can
t
be obtained with less
material
t i l
• Better strength/weight
ratios can be gotten
ti b tt
• Directional mechanical
properties can be
ti b
obtained

52. Issues

53. Conclusions
• We are entering a new paradigm for engineering
– P d
Product engineering, Process engineering, production engineering
i i P i i d i i i
are changing
– We need to address these engineering functions in an integrated
manner
• We have the ability to alter the use performance
characteristics of all future mechanical products
p
– Strength to weight ratio
– Buy to use ratio
– Sustainability product responsibilities
Sustainability product responsibilities
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