Polymer Innovation Day held at the International Institute for Product and Service Innovation.

1. Polymer Innovation: Day 2
12th March 2013
Dr Ben Wood, WMG, University of Warwick
b.m.wood@warwick.ac.uk
@benjaminmwood
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2. Welcome
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3. Housekeeping
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4. The mythical free lunch…
• As always, not quite free!
• Paperwork is our currency
• 2 sets of forms at the end of the
day
• Please leave feedback!
– …and tell us as we go if anything is
wrong
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5. Agenda
0845-0915 Registration, tea and coffee
0915-0945 Welcome and Introductions
0945-1100 Physical to Digital – Laser scanning and producing a CAD file
1100-1115 Refreshments Break
1115-1245 Digital to Physical – 3D printing and how to deal with ‘bad’ CAD
1245-1330 Lunch
1330-1500 Low Volume Manufacturing (including intro to CAD software)
1500-1515 Refreshments Break
1515-1600 Update on latest polymer technologies
1600 on 1 to 1s with the Polymer Innovation team – individual projects
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6. What are we going to talk about?
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7. Introductions
– Dr Alex Attridge
– Dr Greg Gibbons
– Dr Kylash Makenji
– Martin Worrall
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8. Physical to Digital
Scanning technologies and
creating useful data
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9. Physical to Digital
• Contents
– Why go from physical to digital?
– Technologies for collecting data
• Laser Scanning
• X-Ray Computed Tomography (CT)
• Structured Light and Photogrammetry
– Laser scanning demo
– Case study examples
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10. Why Physical to Digital?
• There are a number of reasons:
– Measurement/CAD comparison
– Simulation/virtual testing
• CFD for fluid flow or aerodynamic modelling
• FEA for stress analysis
– Create tooling from a physical prototype
– Benchmarking competitor product
– Reverse engineer to surface model or CAD
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11. Why Physical to Digital?
Colour chart and measurements showing deviation from CAD
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12. Why Physical to Digital?
Creation of an FE mesh for a fatigue crack specimen to help
understand the effect of the crack on performance of the part
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13. Why Physical to Digital?
Creation of a digital surface model from a 1/3 scale Le Manns
Prototype class clay model, to enable a full-scale physical model
to be machine cut for use as a plug for the bodywork mouldings
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14. Why Physical to Digital?
Internal benchmarking of an automotive switchgear mechanism,
carried out as part of a “switch feel” customer clinic study
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15. Why Physical to Digital?
Reverse engineering to CAD of a suspension component from a
classic rally car to improve strength and compatibility with
modern suspension leg/damper technology
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16. Collecting data
• Different technologies for capturing 3D
surface geometry:
– Laser scanning
– X-Ray CT scanning
– Structure light scanning (white/blue)
– Photogrammetry
• Different technologies for different
applications
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17. Laser scanning
• Typically utilises Class 2 red laser light
• Move laser “stripe” over the surface to be measured
• “Stripe” is actually made up of hundreds of points
• Point cloud of data collected – x, y, z, co-ordinates
• Post-processing required but easy to create mesh
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18. Laser scanning
Point Cloud (XYZ)
Accuracy 10µm – System Accuracy approx 40µm
75 stripes/sec - 1000 points/sec data collection
Digital Calibration for every point captured
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19. Multiple lasers
Line Scanner Cross Scanner
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20. Laser scanning
Manual Measurement Arm
(Faro, Nikon, Roma etc.)
Optical CMM
On-CMM laser scanning head
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21. Laser scanning
• Good for collecting complex surface geometry
• Software can identify and characterise features
• CMM or portable systems
• Simple to use – quick results
• Data captured not perfect – line of sight issues
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22. X-Ray CT scanning
• Uses X-ray technology to create a digital 3D
model of the object scanned
• Similar concept to medical CT, but much higher
powered and much more accurate
• Limit to size and density of object to be scanned
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23. CT Scanning of an object to get Projection Images
- Using XT 320 H Machine
Object with a Projection Image
cylindrical hole on screen
inside
Detector
Projection Image at Projection Image at
angle 2 deg. angle 1 deg.
X-ray source
Rotary table
STL format export
DICOM Image series export
Point cloud data export
Reconstructed 3D model visualization as 3D object reconstruction by back-projecting the
stack of images - Using visualization software projection images - Using reconstruction software
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24. X-Ray CT scanning
• Excellent technology for internal inspection
• Typically good quality data generated
• Very large file sizes
• Struggles with big changes in density
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25. Structured light
Traditionally white light
More recently blue light
Projects pattern on to surface
Pattern is distorted and captured
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26. Structured light
GOM
Phase Vision
Breuckmann
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27. Structured light
Often used to characterise panels,
clay models, people(!) etc.
Good for large surfaces
Not so good for smaller objects
Can take a while to set up
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28. Photogrammetry
Digital SLR
Approx 60 photographs
Cloud-based software
3D digital model
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29. Digital to Physical
Additive Layer Manufacturing
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30. Digital to Physical
• Contents
– Data generation for ALM
• Data sources and examples
• Data repair
– System setup – an overview
– System set-up - practical hands-on)
– ALM – ‘the real deal’
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31. DATA GENERATION
15/03/2013 31
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32. Data Generation
• All systems use a ‘.STL’ file:
– Surface triangulated mesh file representing the
surface of a component
• STL files can be generated from
– Directly from export of 3D CAD
– Surface scan data
– Volumetric (e.g CT data)
• Data from any of these methods may require pre-
processing to be useable in ALM
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33. STL files from CAD
• Use ‘export ‘or ‘save as’ function to create STL
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34. STL files from surface scan
• Scan of iPhone 4 case:
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35. STL from CT/MRI scan
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36. Errors in STL files
• Some STL files can be very poor quality
• Particularly from scan or CT…
…but can be poor CAD:
– Missing surfaces
– Gaps
– Intersecting surfaces
– Inverted triangle
normals
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37. Errors in STL files
• Most ALM systems will not tolerate this and will
require a ‘perfect’ STL file
– One single continuous surface
– All surface normals are correct
• Software is available to fix errors relatively easily
15/03/2013
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38. System Setup – Overview
• STL file is the starting point for
any ALM system
• STL may contain colour
information (color STL)
– Currently only ZCorp systems
– Mcor about to release colour
system based on bonded paper
sheets (Iris)
• VRML colour files are also
accepted in ZCorp systems
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39. System Setup – Overview
• All system have proprietary software,
e.g:
– Insight (Stratsys – FDM)
– Objet Studio (Objet - MJM)
– Zprint (ZCorp – 3D Printing)
• Functions available:
– Operators on model
• E.g. rescale, rotate, translate, copy
– Support generation
– Selection of build parameters
• Usually defaults, but can ‘play’ on some
systems
– Obtain time, material usage information
• Useful for quoting purposes
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40. System Setup – Overview
• Some systems require a support
structure to be generated
• This is always necessary for non-powder
bed based systems
• Support acts as a surface to accept the
next layer
• The system interface software generates
this automatically
• Some control on the type of support is
allowed, usually to minimise material
usage
– Density
– Shape
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41. System Setup – Overview
• Additional functionality is available with the ‘new’ multi-
material printers, giving the ability to:
– insert an assembly and define the type of material of each part in the
assembly
– overcoat with materials
– choose glossy or matte surface finish
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42. ADDITIVE MANUFACTURING– THE
REAL DEAL
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43. Additive manufacturing– the real deal
• Materials
• Accuracy
• Resolution
• Sizes
• Time
• Costs
• ‘non added value’ activity
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44. Polymers
• Most common thermoplastics are:
– SLS (PA, PS)
– FDM (ABS, PLA, PC, PEEK)
• Most common thermosets are:
– Acrylic (MJM)
– Epoxy (SLA)
– Wax-like (for investment casting)
• The HDT of FDM materials is equal to the IM grade
• The HDT of other polymers is usually lower than 500C
• High temperature polymers are available
– PEEK (SLS)
– PPSF, ULTEM (MJM)
• Transparency is available but not for FDM and SLS
– Translucency is available for FDM (ABSi - Methyl methacrylate-acrylonitrile-butadiene-
stryrene copolymer)
• Fire retardancy is available (most systems)
• Biocompatibility is available (non-implantable) for most systems
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45. Metals
• Most metals processed using SLS
• Wide range of commercial materials
– Ti, Ti alloys, stainless steel, Inconels, CoCr, Maraging steel,
tool steel, aluminium…
• Now systems processing Ag, Au, Pt (EOS-Cookson
Metals tie-up)
• Mechanical properties usually approach or match
those of wrought materials
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46. Accuracy, Resolution
• Resolution and accuracy are not the same!
• Accuracy and resolution are complex and are highly
dependent on system and component size, and on quality of
calibration
Accuracy Resolution
x y z x y z
SLS 30 30 20 100 100 20
metal
SLS 100 100 100 50 50 50
polymer
MJM 20 20 16 40 40 16
3DP 250 250 89 100 100 89
15/03/2013
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47. Size
• Polymers
– Wide range of size capabilities (50mm-3m+)
– Small bed sizes often have higher resolution
– Large bed sizes often have faster build rates
• Metals
– Most metals systems have beds
<300x300x300mm
– Soon to be released have 500x500x300mm
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48. Time
• Time is very difficult to assess from an STL file since:
• Time is dependent upon:
– Part volume
– Part dimensions
– Part orientation
– Material used (even in the same process)
– Level of finishing required
– How much you want to pay (premium for queue jumping)
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49. Costs (using a bureau)
• Not easy to assess just from an STL file since:
• Cost is very much dependent upon:
– Volume of the component (amount of material)
– Part dimensions
– Cost of the material
– Amount of support material
– Resolution required (number of slices)
– Orientation required (taller the dearer)
– Number of parts required (often cheaper per part to have
multiples – especially for SLS)
– Level of finish required
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50. Costs (in-house)
• If you have system in-house, need to consider:
– Maintenance costs
– Material costs (including scrap, waste)
– Consumables costs
– Infrastructural costs
– Labour costs (set-up and clean-down)
• Costs can vary widely depending on the system
– System - £500-£1m+
– Maintenance – £100 – £30k PA
– Material - £1 - £600 /kg
– Infrastructural - £0 - £100k +
– Labour - £5 - £200 per part
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51. Low Cost Systems
• Recent huge rise in ultra-
low cost systems
– Makerbot, BFB, Cubify …
• Based on FDM technology
• £500 - £2,500
• Material costs ~£20/kg
• No dedicated computer
• No training
• Simple post-processing
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52. Low Volume Manufacturing:
Bridging the Gap
Dr Ben Wood & Dr Kylash Makenji
IIPSI
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53. Outline
• Identifying the problem
– How to go from prototype to production?
• Direct manufacturing methods
• Rapid Tooling
– Indirect
– Direct
• Live demo of direct tooling
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54. The Problem
Injection Moulding
Rotational
Tooling Moulding
Cost Compression
Moulding
Low Volume
CNC Machining
Manufacturing
ALM
1 100 1000 10,000 100,000 1,000,000+
Number of Parts
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55. What is Rapid Tooling?
• Early definition of Rapid Tooling:
“a process that allows a tool for injection moulding and die casting
operations to be manufactured quickly and efficiently so the
resultant part will be representative of the production material.” -
Karl Denton 1996
• With Rapid Tooling now covering a wider range of
applications, this has generalised to:
“a range of processes aimed at reducing both the cost and time for
the manufacture of tooling.”
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56. Classification of Rapid Tooling
• Indirect
– Use of a Rapid Prototype (RP) pattern to manufacture a tool
in a secondary operation
Mould tool
ALM original Make parts
from original
• Direct
– Directly produce the tool using a layer-additive process
Make
ALM tool
parts
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57. Indirect Rapid Tooling
• Cast tooling
– Cast resin tooling
– Cast metal tooling
– Cast ceramic tooling
• Metal spray tooling
– Kirksite thermal spray tooling
– Rapid Solidification Process tooling
– Sprayform tooling
• Indirect laser sintered tooling
– 3D LaserForm process
• 3D Printed tooling
– Extrude Hone Prometal
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58. Cast Resin Tooling
• Obtained by two primary methods:
– Room temperature vulcanised silicone
– Rigid resin tooling
• Both involve the following steps:
ALM Split tool, Fill cavity
Blocking Pour over
model of remove with liquid
out liquid resin
original original resin
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59. Cast Resin Tooling
Room Temperature Vulcanised (RTV) Silicon tooling
• Silicone rubber tools for vacuum casting of
(generally) polyurethane parts
• Resin parts vacuum cast or injected into tool
• Expensive materials
• Low volume (~30 parts) / extremely rapid (1-2
days)
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60. Cast Resin Tooling
Rigid resin tooling
• Aluminium filled epoxy resin tools used for
injection / blow moulding
• Difficult and slow to mould parts
– Need to protect tool, so not „real‟ settings
• Expensive materials
• Volumes up to ~500 / very rapid (3-5 days)
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61. Direct Rapid Tooling
• Direct metallic tooling
– Direct laser melted metallic tooling
• EOSint M DirectTool
• MCP Selective Laser Melting (SLM)
• Direct polymeric tooling
– 3D Printed mould inserts
• Object Connex 260
• Fortus FDM
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62. Laser Melted Metallic Tooling
Many similar processes, 2 most employed are:
• DirectTool – EOS GmbH
• Selective Laser Melting (SLM) – MCP Inc
Process involves:
• Generating CAD model of tool
• Additive manufacture of tool by selectively melting thin layers of fine
metal powder using a laser
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63. Laser Melted Metallic Tooling
DirectTool (EOS Gmbh)
• Latest system: EOSINT M270
• Materials:
• DSH20 (tool steel)
• DS20 / 50 (20mm and 50mm steel)
• DM20 / 50 (20mm and 50mm bronze)
• Very hard tooling possible (42HRc)
• Very high accuracy (~50mm) / 20mm
layers
• Conformal cooling channels
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64. Laser Melted Metallic Tooling
Selective Laser Melting (MPC Inc)
• Latest system: „Realizer‟
• Materials:
• Any metallic powders 10-30mm
• Stainless steel most common
• Very high accuracy (~50mm) / 50mm
layers
• Conformal cooling channels
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65. ALM Polymer Inserts
• Manufacture a tool insert by ALM (Connex
260)
– Accurate
– Good surface finish
– Very rapid (30 mins-2 hours)
– £10-£50 material cost
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66. ALM Polymer Inserts
• Ready for mass production
– Injection mould tooling
– Lower cost ‘pocket’ tool
– Can be used with wide range of inserts
• Easy, quick and inexpensive to make changes
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67. Workshop
INJECTION MOULDING TOOL
INSERTS
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68. Polymers
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69. Material Compatibility
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70. Process Comparison
Capital
Process Equipment Production Rate Tooling Cost Part Volumes
Cost
Compression
Low Slow Low 100 – 1 mill
Moulding
Vacuum Forming Medium Medium Medium 10,000 – 1 mill
Injection Moulding High Fast High 10,000 – 100 mill
Extrusion Medium Fast Low – Medium Med - High
Blow Moulding Medium Medium Medium 1,000 – 100 mill
Rotational
Medium Slow Medium 100 – 1 mill
Moulding
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71. Summary
• Many potential manufacturing routes for low
volume
– Right choice depends on part and material
• ALM can be used for much more than
prototyping
– Key to most rapid tooling methods
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72. Adding Functionality
IIPSI Capabilities and State of the Art
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73. Outline
• Shape memory polymers
– Active disassembly
• Printed and plastic electronics
– Conductive polymers
– Low cost applications
– Integration
• What would you like to see?
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74. Shape Memory Polymers
• Can be ‘programmed’ to change shape when
given a trigger
• High material cost = niche applications
Mould Force into Set
Return to
part temporary temporary
original shape
shape shape
Heat Cool Heat
FORCE Restrain
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75. SMP Research Focus
Medical
Aerospace/defence –
morphing wings Outer Space – Zero Gravity
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76. SMPs for SMEs!
• ‘Active’ disassembly
– Ideal for automotive, consumer electronics
• Automatically release at end of life
– Materials separation, recycling
• Low complexity
– Maximise added value
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77. PLASTIC AND PRINTED
ELECTRONICS
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78. Conductive Polymers
• Actual conductive polymers not common
– Difficult to process, not like plastics
– Normally dissolved in solvent
• Applications in PV and EL/OLED
– Useful as part of a printed or plastic electronic
component
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79. Plastic and Printed Electronics
• Growth area
– Funding opportunities
• Costs reducing
– Expensive materials vs volume production
• Key applications
– Display technology
– ‘Smart’ Packaging
– IoT
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80. Plastic Electronics
• Electroluminescence (EL)
– Low energy, low heat lighting
– Simple circuit
PEDOT-PSS transparent electrode +ve
Zinc Sulphide Phosphor
LIGHT Dielectric
-ve Reflective (silver) rear electrode
Surface
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81. EL Applications
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82. Low Cost Plastic Electronics
Airbrush Method
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83. Low Cost Plastic Electronics
Screen Printing Type Method
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84. Low Cost Plastic Electronics
Direct In-Mould Layer
Application
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85. Low Cost Plastic Electronics
Post Mould Layer Application
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86. Printed Electronics
• Inkjet printing technology
– Silver and carbon -based inks
• Simple, low voltage circuits
– Resistors
– Switches
– Conductive tracks
– LEDs
– (Low power) batteries
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87. Hybrid 3D Printing
• Bespoke system hybridising
MJM with syringe deposition
– 2 x 512, 14pl nozzle heads,
individually addressed
– High viscosity liquid dispensing
– Continuous flow for deposition of
resins with highly suspended solids
– SmartPump for deposition of higher
viscosity resins and pastes at
extremely high resolution
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88. Hybrid 3D Printing
• Integrated manufacture
– Functional components
– Electronic circuits
• Facilitates adding of functionality and
connectivity
– Eg interactive books
– Internet of Things (IoT)
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89. Summary
• Complex circuits require expensive kit and
specialist knowledge
• Market is growing, costs coming down
– Printing technology, roll-to-roll
• Simple circuits achievable with low capital
– Layer-by-layer deposition of materials
• Future is in integration
– IoT
– https://www.youtube.com/watch?v=zG2dvxSKEGU
– https://www.youtube.com/watch?v=Kgw51_PtDSs
© 2013