Energy Efficient Lamination of Flat Glass via Radio Frequency Pressing

Shawn M. Allan*Morgana Fall, Dr. Holly S. Shulman

Ceralink Inc.

Ceralink Inc. develops advanced materials,green processes, and new products for industry.

Materials Science & Technology 2007Processing and Product Manufacturing:

Environmental Issues in the MaterialScience and Technology Industries

Green Materials and Processes

September 19, 2007 10:20 am

Roadmap

Products and marketsNeed for manufacturing alternativesApproach for low energy, green laminationBenefits and resultsConclusions

Products and MarketsLaminated flat glass, ceramics, safety plastics, composites

World laminated flat glass market is $11.7B, USA $2.7BGrowth (7-8%) driven by security and safety applications, regulations

Architectural GlassAuto Safety GlassHurricane and Seismic Protection GlassAerospace and Marine Glass and Composites

Transparent Armor and ShieldsLaminated CompositesSolar (Photovoltaic) PanelsMultilayer Ceramic Composites

Need: Manufacturing AlternativesEnergy Policy Act of 2005 (EPAct), Section 106

Reduce U.S. industry energy use 25% by 2017

Government vehicle ejection regulations (auto side windows)

Commodity pricing

Demand for low cost laminated photovoltaic (PV) panels

Growth of transparent ceramic armor markets

State of the art glass lamination

© 2007 DigiGlass Australasia Pty Ltd.

Laminators use 3 main types of interlayersPolyvinyl butyral (PVB)

Clear, printedEthylene vinyl acetate (EVA)

Clear, colored, opaqueThermoplastic Polyurethane (TPU)

Flat, curved, textured, or tempered glass

Processing requiresPre-processing rolling (de-airing)Autoclaving (PVB, TPU)Vacuum oven (EVA)

Large batches, 1 to 6 hour processes

RF Lamination TechnologyProduction method to make laminates,

faster and more efficient

1 minute cycleCuts energy up to 95%Heat interlayer directlyApply pressureReplace 3 steps with 1Prototype stage

GlassCeramicsSafety plastics Composites

RF Lamination TechnologyProduction method to make laminates,

faster and more efficient

1 minute cycleCuts energy up to 95%Heat interlayer directlyApply pressureReplace 3 steps with 1Prototype stage

GlassCeramicsSafety plasticsComposites

GlassVinylGlass

RF Lamination TechnologyProduction method to make laminates,

faster and more efficient

1 minute cycleCuts energy up to 95%Heat interlayer directlyApply pressureReplace 3 steps with 1Prototype stage

GlassCeramicsSafety plasticsComposites

Prelaminate

RF Lamination TechnologyProduction method to make laminates,

faster and more efficient

1 minute cycleCuts energy up to 95%Heat interlayer directlyApply pressureReplace 3 steps with 1Prototype stage

GlassCeramicsSafety plasticsComposites

Electrode/Platen

Electrode/Platen

RF Lamination TechnologyProduction method to make laminates,

faster and more efficient

1 minute cycleCuts energy up to 95%Heat interlayer directlyApply pressureReplace 3 steps with 1Prototype stage

GlassCeramicsSafety plasticsComposites

Electrode/Platen

Electrode/Platen

RF Energy & pressure

RF TechnologyRF field created between parallel electrodes

Electrodes double as press platens

Used widely for drying paper and wood, and sealing certain plastics

RF (1 to 300 MHz) dielectrically heats materialsat ISM allowed frequency, 27.12 MHz

Project ApproachExperimental

Vary glass and interlayer pairings to identify usesClear, tinted, metal coated glass, acrylic, polycarbonatePVB, printed PVB, EVA, and TPU interlayers

Vary RF power, time, and pressure10 – 20 Watts/cm²10 to 120 seconds10 to 100 psi

AnalysisVisual inspection for defectsDurability – boil and bake testsOptical transmissionEnergy analysis

Interlayers & Structural LayersPVB

DuPont Butacite® B5Solutia Saflex® RF41Solutia RS1220

Printed PVBDuPont SentryGlass Expressions®

EVASekisui S-LEC® EN FilmBridgestone EVASAFETM

Nanjing Kin Yong Fa coloredNanjing Kin Yong Fa opaque

TPUDeerfield Urethane Dureflex® A4700

Clear & Tinted GlassAutoWindow

Low-E Glass

Acrylic – Acrylite FF®

Polycarbonate – Lexan PC®

Feasibility ResultsVisual

InspectionOptical

TransmissionBake Test

Boil Test

Ambient Aging

Glass + Solutia PVB Yes

Edge haze

Yes

2 years

2 years

2 years

2 monthsEdge delam

2 months

2 months

2 months

5 months

Glass + DuPont SentryGlass PVB

Yes

Glass + Nanging EVA Yes Yes

5 months

Glass + Bridgestone EVA

Yes Yes Yes

Yes

Glass + DuPont PVB Yes

Glass + Sekisui EVA Yes Yes

Low-E + EVA Yes Yes

Glass + TPU Yes Yes

Polycarbonate + TPU Few bubbles

Acrylic + TPU Few bubbles

Feasibility Examples - PVB

DuPont Butacite® PVBin tinted glass

DuPont SentryGlass®

Printed PVB in clear glass

Solutia Saflex® PVB in clear and tinted glass

Feasibility Examples - EVA

Bridgestone EVASAFETM

Nanjing Kin Yong FaTransparent and Opaque EVA

Sekisui S-LEC® EN

Feasibility Examples - TPU

Polycarbonate Acrylic

Glass

Deerfield UrethaneDureflex® A4700

Low-E (metallized) glassGlass is metallized on one side2 panes laminated with EVASAFETM

Implications for use with photovoltaics and embedded sensors

RF Laminated Low-e Glass150 mm x 150 mm

Energy Efficiency

Efficiency improves as laminate area increases

Energy consumption of processIncreases linearly with area

DurabilityClear glass with Bridgestone EVASAFE and Sekisui S-LEC EVA

RF laminated glass was subjected to EU tests from EN ISO 12543-4:

•Boil, 100 °C, 2 h•Sekisui Passed•Bridgestone Edge Haze

•Bake, 130 °C, 2 h•Sekisui Passed•Bridgestone Passed

Samples were then observed for change ofclarity and defects

Optical TransmissionExample Transmission Spectra

for RF Laminated Glass

Typical average transmission of EVASAFE and glass

RF Laminated glass comparable to conventional process

Scale-up PlansRF lamination of

PhotovoltaicsLED and sensor containing filmsTransparent ceramic armor

Flat glass window size1 to 6 m2

Curved glassAutomotive sidelights & windshieldsArchitectural curved glass

Adhesion testing for comparison to autoclave/vacuum

Make RF lamination available to manufacturers

Summary of RF Glass LaminationMaterials comparable to autoclave and vacuum processed laminates

Energy saving technology1 minute semi-continuous process

1-6 hour batch process95% energy consumption reduction

Broad scope of useInterlayersStructural layersMetal coated glass

Path for further development and commercialization

Acknowledgements

This material is based upon work supported by the Department of Energy Office of Energy Efficiency and Renewable Energy

under Award Number DE-FG36-06GO16043.

Ceralink Contact InfoCeralink has applied for U.S. and international patents

for RF Press Lamination Technology

Contact: Shawn AllanSr. Materials Engineer

(518) 283-7733shawn@ceralink.com

Ceralink Inc. develops advanced materials,green processes, and new products for industry.