UV CURING IN 3D PRINTINGLance R. Pickens,MadeSolid, Inc.

August 27th 2014

Digital Model Physical Object

CONSUMER 3D PRINTINGLargely dominated by thermoplastic extrusion printers

Robotic Arm + Glue Gun = FDM 3D Printers

Pictures: http://en.wikipedia.org/wiki/Armatron

3D PRINTERS 2014

David assembling an SLA 3D Printer, ca 2013

3D PRINTING INDUSTRY METRICS

Industrial Systems• >$500 Million spent on materials• >$200 Million on Photopolymers• 21% Annual Growth

* Wohlers Associates, Inc.,* 3DPrintingIndustry News* Gartner

Consumer 3D• ~35,000-50,000 2012• ~70,000-95,000 2013• >1,000,000 2017

Consumer 3D Printer adoption is difficult to measure accurately

CONSUMER 3D PRINTERSThermoplastic Extrusion

pros• Easy Implementation• Variety of materials• mechanical performance

cons• slow• low resolution• variety of failure modes

Photopolymer Systems

pros• high resolution• low failure rate• speed

cons• expensive to implement• lack of software tools

SLA VS FDM

UV PHOTOPOLYMERIZATION

Photoinitator +Monomer+Light=Polymer

PHOTOINITIATORAbsorbs photons

Wavelength SpecificReaction specific

Wavelength Specificity Determines lamp source

Benzophenone

MONOMERS• Contain High energy bonds

• Can link up to other monomers through new chemical bond formation

• Typically Acrylate or Epoxy type functionality

WHY UV IS HERE TO STAYControlling light is getting easier, cheaper, and faster

UV IN 3D PRINTING?

• SLA: Stereolithography• DLP: Digital Light Projection• Material Jetting

3 Different kinds of UV based 3D Printers

UV IN 3D PRINTING

SLA: Stereolithography

Original 3D printing technology, invented by Charles Hull over 30 years ago as a direct result of UV cured coatings.

Light source is a laser which traces out a pattern onto a thin layer of monomer+photoinitiator combo

"Comparison CD DVD HDDVD BD" by Cmglee - Own work. Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Comparison_CD_DVD_HDDVD_BD.svg#mediaviewer/

File:Comparison_CD_DVD_HDDVD_BD.svg

WAVELENGTH IS KEY

SLA PRINTERSAdvantages:

• Larger build areas than DLP

• > power/cm2 (Lasers!)

Disadvantages:

• XY resolution

• beam path generation

• Supported overhangs

SLA PRINTERS

Build Chamber

Laser Optics Unit

IF DLP WERE CHEAP ENOUGH

Build Chamber

Laser Optics UnitProjector

DLP BASED 3D PRINTERS

Consumer Electronic Projector hardware

Superior resolution to SLA

DLP PROJECTORS

Retail Price of HD DLP

50X drop in price

WHY UV WILL DOMINATE 3D PRINTING IN THE NEXT 5 YEARS• Decreasing cost of consumer electronics

• Increasing demand for HD Entertainment

• Easier tool path creation, smaller file sizes

• Wider variety of materials and chemistry

• User experience

• Higher detail

• Moore’s Law in your sails

RESOLUTION

50um    X  50um    Y  20um    Z

ADVANCED MATERIALS?Photopolymerization enables:

• Precise control over reaction volume

• Broad feedstock selection

• Wide variety of chemistry towards new function

• Rapid Development Cycles

WHAT TO EXPECT FROM CHEMISTRY

Renewable Feedstocks

Stimuli responsive materials

Improved mechanical performance

Nanoscale structural features

…

PHOTOCHEMISTRY TECHNOLOGY IS A FOUNDATIONAL TECHNOLOGY FOR THE FUTURE OF 3D PRINTING