Polymer innovationday2 110313_share

© 2013

Polymer Innovation: Day 2 12th March 2013

Dr Ben Wood, WMG, University of Warwick

[email protected]

@benjaminmwood

mailto:[email protected]

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Welcome

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Housekeeping

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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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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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What are we going to talk about?

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Introductions

– Dr Alex Attridge

– Dr Greg Gibbons

– Dr Kylash Makenji

– Martin Worrall

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Physical to Digital

Scanning technologies and

creating useful data

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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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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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Colour chart and measurements showing deviation from CAD

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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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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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Internal benchmarking of an automotive switchgear mechanism, carried out as part of a “switch feel” customer clinic study

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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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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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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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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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Multiple lasers

Line Scanner Cross Scanner

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Laser scanning

Manual Measurement Arm (Faro, Nikon, Roma etc.)

Optical CMM

On-CMM laser scanning head

http://metrisusa.files.wordpress.com/2011/11/k600_cutout-copy-yellow1.gif

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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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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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Projection Image at angle 1 deg.

Projection Image at angle 2 deg.

3D object reconstruction by back-projecting the projection images - Using reconstruction software

Reconstructed 3D model visualization as stack of images - Using visualization software

STL format export

DICOM Image series export

Point cloud data export

CT Scanning of an object to get Projection Images - Using XT 320 H Machine

X-ray source

Rotary table

Object with a cylindrical hole inside

Detector

Projection Image on screen

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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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Structured light

Traditionally white light More recently blue light Projects pattern on to surface Pattern is distorted and captured

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Structured light

GOM Phase Vision

Breuckmann

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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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Photogrammetry

Digital SLR Approx 60 photographs

Cloud-based software 3D digital model

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Digital to Physical

Additive Layer Manufacturing

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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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DATA GENERATION

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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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STL files from CAD

• Use ‘export ‘or ‘save as’ function to create STL

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STL files from surface scan • Scan of iPhone 4 case:

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STL from CT/MRI scan

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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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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

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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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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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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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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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ADDITIVE MANUFACTURING– THE REAL DEAL

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Additive manufacturing– the real deal

• Materials

• Accuracy

• Resolution

• Sizes

• Time

• Costs

• ‘non added value’ activity

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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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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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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

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Accuracy Resolution

x y z x y z

SLS metal

30 30 20 100 100 20

SLS polymer

100 100 100 50 50 50

MJM 20 20 16 40 40 16

3DP 250 250 89 100 100 89

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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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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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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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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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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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Low Volume Manufacturing: Bridging the Gap

Dr Ben Wood & Dr Kylash Makenji

IIPSI

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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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CNC Machining

The Problem

Tooling Cost

Number of Parts

10,000 100,000 1 1,000,000+ 1000 100

ALM

Injection Moulding

Compression Moulding

Rotational Moulding

Low Volume Manufacturing

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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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Classification of Rapid Tooling

• Indirect

– Use of a Rapid Prototype (RP) pattern to manufacture a tool in a secondary operation

• Direct

– Directly produce the tool using a layer-additive process

ALM original Mould tool

from original Make parts

ALM tool Make parts

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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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Cast Resin Tooling

• Obtained by two primary methods: – Room temperature vulcanised silicone

– Rigid resin tooling

• Both involve the following steps:

ALM model of original

Blocking out

Pour over liquid resin

Split tool, remove original

Fill cavity with liquid

resin

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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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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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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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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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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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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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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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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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Process Comparison

Process Capital

Equipment Cost

Production Rate Tooling Cost Part Volumes

Compression Moulding

Low Slow Low 100 – 1 mill

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 Moulding

Medium Slow Medium 100 – 1 mill

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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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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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Shape Memory Polymers

• Can be ‘programmed’ to change shape when given a trigger

• High material cost = niche applications

Heat

FORCE

Mould part

Force into temporary

shape Cool

Restrain

Set temporary

shape Heat

Return to original shape

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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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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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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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• Electroluminescence (EL)

– Low energy, low heat lighting

– Simple circuit

PEDOT-PSS transparent electrode

Zinc Sulphide Phosphor

Dielectric

Reflective (silver) rear electrode

Surface

+ve

-ve

LIGHT

Plastic Electronics

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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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• 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

Hybrid 3D Printing

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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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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

https://www.youtube.com/watch?v=zG2dvxSKEGU

https://www.youtube.com/watch?v=zG2dvxSKEGU

https://www.youtube.com/watch?v=Kgw51_PtDSs

Polymer innovationday2 110313_share

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