uv fluorescent testing or xenon - institute of …materialsfinishing.org/attach/15. the right...

UV Fluorescent Testing or Xenon

Arc Testing….

The Right Choice.

The Right Choice?

QUV Weathering Tester Q-Sun Xenon Tester

No Tester is Perfect for All

Applications.

A tool for improving

product durability,

and for reducing costs.

Weatherability Testing

Choose an accelerated test

method that matches:

• Your Materials

• Their End Use Environment

• The Type of Degradation that Occurs

The Right Choice

• Forces of Weathering

• Technology of UV Fluorescent Testing

• Technology of Xenon Testing

• Decision Criteria

Why Test?

• Meet Specifications

• Avoid Catastrophes

• Enhance Your Reputation

• Verify Supplier Claims

• Improve Product Durability

Why Test?

• Save on Material Costs

• Expand Existing Product Lines

• Enter New Markets

• Outrun the Competition

• Stay Ahead of Regulations

• Verify Customer Complaints

Forces of Weathering

• Sunlight

• Temperature

• Moisture

Spectrum

of

Sunlight

Electromagnetic Spectrum

International Society for Illumination

• CIE Publication #85 Table 4

• (Peak Natural Daylight Standard)

• 0.68 W/m2 @ 340 nm

UV is Only 5% of Sunlight, but

UV Causes Virtually All Polymer

Degradation!

Short Wavelengths

Are More Damaging

250 350 450 550 650

0.0

0.5

1.0

1.5

2.0

Wavelength (nanometers)

Irra

dian

ce

W/m

2/nm

Visible LightUV Region

UV

-A

UV

-B

UV

-C

Summer Sunlight Standard

Effect Of Window Glass

• Ordinary Glass Filters Out

• Wavelengths

• Shorter Than 310 nm

260 280 300 320 340 360 380 400

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Wavelength (nanometers)

Irra

dia

nce

W

/m2

/nm

Direct

T hroughWindow

Glass

Sun ligh t

Filtering Through

Window Glass

Wavelength Regions of UV

UV - C

100 – 280 nm

Found in outer space; Can

cause unnatural damage

UV – B

280 – 315 nm

Includes shortest wavelengths

at earth’s surface: severe

polymer damage; absorbed by

window glass

UV – A

315 – 400 nm

Causes some polymer damage

Different Materials Have

Different Wavelength Sensitivity

Spectral sensitivity, carbonyl formation vs.

wavelength of irradiation,

with dosage of 1 MJ/m2 at each wavelength.

polyamides, change in mass

vs. wavelength of irradiation,

with dosage of 1 MJ/m2 at each

wavelength.

Small Changes

in Formulation

Can Result in Large Differences

in UV Resistance

In a Laboratory Test

Small Shifts in UV Spectrum

Can Result in Large Differences

in Degradation

Short Wavelengths -

Polymer Degradation

Long Wavelengths -

Fading & Color Change

Choose A Laboratory Spectrum

Based On

• Material Sensitivity

• Type of Degradation

• Service Environment

Additional Characteristics

Affect Spectral Sensitivity

• Color

• Thickness

• Stabilization

Higher

Temperatures Often

Increase the Rate of

Degradation

Temperature

Primary

Photochemical Reactions

Are Not

Affected by Heat

Secondary Reactions

Are

Affected By Heat

Effect of Temperature

Oxidation Rate of Polyethylene

Darker Color = Higher Temperature

Fischer and Ketola, 1993

Moisture

Q-Panel’s Time of Wetness Research

Things Are Wet Outdoors Longer

Than You Think

Time of Wetness vs. Rainfall - Miami, FL

Dew, Not Rain

is the Source of

Most Outdoor Wetness

Effect of Moisture

Don’t Underestimate the Effect

of Moisture

• Changes The Rate Degradation

• Changes Mode Of Degradation

With 12 hours Per Day of

Wetness Outdoors,

How can you accelerate

wetness in the Laboratory?

With 12 hours Per Day of

Wetness Outdoors,

How can you accelerate

wetness in the Laboratory?

Increase the Temperature of Wetness.

All Weathering Testers Are

Screening Devices

No Perfect Simulation

The Right Choice?

QUV Weathering Tester Q-Sun Xenon Tester

Fluorescent UV Tester

QUV Accelerated

Weathering

Tester

model QUV/se

Fluorescent UV Lamp

Specimen Holders

0.0

0.2

0.4

0.6

0.8

1.0

1.2

270 290 310 330 350 370 390

Wavelength (nm)

Irra

dia

nc

e W

/m²/

nm

UV-B Lamps

UVA-340 Lamps

0.0

0.2

0.4

0.6

0.8

1.0

1.2

260 280 300 320 340 360 380 400

Wavelength (nm)

Irra

dia

nce

(W

/m²/

nm

)

Sunlight

QUV with UVA-340 lamps

Solar Eye™

Irradiance Control

Automatic

Irradiance

Control

5,600-hour lamps

2-hour lamps

Lamp Aging – Automatic Control

UVB-313 Lamps QUV/se

0.0

0.5

1.0

1.5

270 290 310 330 350 370 390

Wavelength (nm)

Irra

dia

nc

e (

W/m

²/n

m)

Effect of Intensity Control

Intensified 75%

Typical Intensity

Sunlight

UVA-340 Lamps QUV/se

Effect of Irradiance Level

Effect of Irradiance Level

Effect of Irradiance Level

Speed vs. Realism

Increasing the stresses

often decreases correlation

Calibration with AutoCal Radiometer

Fluorescent Lamp Advantages

• Fast results

• Very stable spectrum

• Minimal maintenance

• Simple calibration

• Low cost

QUV Moisture

• Condensing Humidity

• Water Spray

QUV

Schematic

Condensation Advantages

• Identical to natural wetness (dew)

• Elevated temperature = acceleration

• Pure water: condensation process

creates distilled water

• Easy to use

Water Spray Option

Erosion &

thermal shock

ensure parts

get wet

Arwood European Wood Coatings

Research Project

• Participants:

• 10 wood research institutes

• 4 industrial partners: Tikkurila Oy,

Gori-Dyryp, ICI Paints Inc., Cecil

• Objective:

• Quickly assess the durability of

exterior wood coatings to meet

environmental issues

• Develop accelerated test device

for small-medium size companies

Requirements

Arwood

QUV/spray: simulate effects of

sunlight, increase moisture

content of wood, produce surface

erosion & degrading of material

Cycle:

Condensation - 24h 45ºC

Light - UVA-340 2.5h 60ºC

Spray - In Darkness 48h

Duration - 2016 hours

Solution

Basis for proposed revision to

CEN test method Pr ENV 927-6

“Paints & Varnishes - Coating

Systems for Exterior Wood”

State of the Art Fluorescent UV

Tester: QUV

• Irradiance Control

• Calibration with AutoCal

Radiometer

• Self-diagnostic

• Ethernet Capabilities

Making The Right Choice

QUV Weathering Tester Q-Sun Xenon Tester

Rotating Drum Schematic

Flat Array Schematic

Uniformity

Advanced Flat Array geometry gives

uniformity comparable to Rotating Drum

testers

Xenon Lamp Cooling

• Operate at high wattage & high intensity

• Lamps generate considerable heat

• Lamps must be cooled

• There are two methods of lamp cooling

• Water-cooled

• Air-cooled

Water-Cooled Xenon Lamp and

Filters

Air Cooled Lamp

0.0

0.5

1.0

1.5

2.0

2.5

3.0

250 300 350 400 450 500 550 600 650 700 750 800

Wavelength (nm)

Irra

dia

nc

e (

W/m

²/n

m)

Q-Sun with

Daylight Filter

QUV with

UVA-340 Lamps

Sunlight

QUV, Xenon, Sunlight...

Xenon Arc Spectra Choices

• Effect of Filters

• Irradiance Control

Filter Selection Summary

• Simulate Service Environment

• Consider Material Spectral

Sensitivity

Filters Alter Xenon Spectrum

Daylight Filters

(exterior exposures)

Extended UV

(auto specs., fast results)

Window Glass

(indoor exposures, textiles, inks, etc.)

Window Glass Daylight

Q-Sun Filters

SPD's of Q-Sun and UVA-340 Lamps vs. Sunlight

0.0

0.5

1.0

1.5

2.0

2.5

3.0

250 300 350 400 450 500 550 600 650 700 750 800

Wavelength (nm)

Irra

dia

nc

e (

W/m

²/n

m)

Xenon With Daylight Filters

Sunlight

Xenon with

Daylight Filter

0.0

0.2

0.4

0.6

0.8

1.0

1.2

260 280 300 320 340 360 380 400

Wavelength (nm)

Irra

dia

nc

e (

W/m

²/n

m)

Xenon with Daylight Filters

Xenon with

Daylight Filter

Sunlight

Xenon with Extended UV Filters vs. Sunlight

0.0

0.5

1.0

1.5

2.0

2.5

3.0

200 300 400 500 600 700 800

Wavelength (nm)

Irra

dia

nc

e (

W/m

2/n

m)

Sunlight

Xenon with Extended UV Filter

0.0

0.2

0.4

0.6

0.8

1.0

1.2

260 280 300 320 340 360 380 400

Wavelength (nm)

Irra

dia

nc

e (

W/m

²/n

m)

Xenon with Extended UV Filters

Xenon with

Extended

UV Filter

Sunlight

0.0

0.5

1.0

1.5

2.0

2.5

3.0

250 300 350 400 450 500 550 600 650 700 750 800

Wavelength (nm)

Irra

dia

nc

e (

W/m

²/n

m)

Xenon with Window Glass Filters

Xenon with Window

Glass Filter

Sunlight

Through

Window Glass

Sunlight

0.0

0.2

0.4

0.6

0.8

1.0

1.2

260 280 300 320 340 360 380 400

Wavelength (nm)

Irra

dia

nc

e (

W/m

²/n

m)

Xenon with Window Glass Filters

Sunlight

Sunlight Through

Window Glass

Xenon with

Window

Glass Filter

Irradiance Control

• Control Intensity

• Select Control Points

• @ 340 nm

• @ 420 nm

• 285-400 nm (TUV)

Irradiance Intensity

• Wide Range

• Dependent on Filter Configuration

• Control Point

• Irradiance Control

• Feedback Loop Control

• Light sensor

• Control module

• Xenon arc lamp

0.0

0.5

1.0

1.5

2.0

2.5

3.0

250 300 350 400 450 500 550 600 650 700 750 800

Wavelength (nm)

Irra

dia

nce (

W/m

²/n

m)

Sunlight

Xenon with Daylight Filter

.68 @ 340 nm Control Point

340 nm Control Point

0.0

0.2

0.4

0.6

0.8

1.0

1.2

260 280 300 320 340 360 380 400

Wavelength (nm)

Irra

dia

nce (

W/m

²/n

m)

340 nm

Control Point

Xenon with Daylight Filter

Sunlight

.68 @ 340 nm Control Point

0.0

0.3

0.5

0.8

1.0

1.3

1.5

1.8

2.0

2.3

2.5

250 300 350 400 450 500 550 600 650 700 750 800

Wavelength (nm)

Irra

dia

nc

e (

W/m

2/n

m)

Xenon with

Window Glass

Filter

Sunlight

through window glass

1.10 @ 420 nm Control Point

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

260 280 300 320 340 360 380 400 420 440 460 480 500 520 540

Wavelength (nm)

Irra

dia

nc

e (

W/m

²/n

m)

Xenon with Window Glass Filter

1.10 @ 420 nm Control Point

Sunlight Through

Window Glass

Lamp Aging

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

280 300 320 340 360 380 400 420

Wavelength (nm)

Irra

dia

nce (

W/m

2/n

m)

0 hour lamp

1500 hour lamp

Sunlight

through glass

420 nm

control point

1.10 W/m2 @ 420nm with Window Glass Filter

Temperature Control with Black

Panel Temperature Sensor

Temperature & Color

Fischer and Ketola, 1993

Chamber Air

Temperature Control

• Required by certain Test Methods

• Necessary to control RH

• Requires advanced Technology to achieve

simultaneous control of Black Panel Temp

and Chamber Air Temp

Water Spray

Spray System for

Xenon Requires

Extremely Pure

Water Input

Q-Sun Spray System

• Single Water Spray

• Dual Spray

• Acid Etch Simulation

• Specialty Solutions

State of the Art Xenon Arc

Tester: Q-Sun

• Irradiance Control

• Choice of Filters

• Calibration with AutoCal

Radiometer

• Simultaneous Control of

Black Panel Temp,

Chamber Air Temp, and

Relative Humidity

QUV

• UVA-340 best simulation

of shortwave UV

• UVB-313 might be too

severe

• No visible light

• Stable spectrum

• Irradiance control

• No RH control

• More aggressive moisture

attack

• Full spectrum

• Best simulation of long

wave UV & visible light

• Spectrum changes over

time

• Irradiance control

• Relative humidity control

• Water spray options

XENON

QUV Is The Most Cost Effective

For Polymer Degradation

• Gloss loss

• Yellowing

• Chalking

• Checking

• Cracking

QUV Is More Realistic For Water

Sensitive Materials

Xenon is best for materials

damaged by visible light

• Indoor end use (furniture lacquer)

• Printing Inks

• Organic Pigments

Xenon is More Realistic For

Testing Lightfastness / Color

Degradation

Choose an accelerated test

method that fits your materials,

their end use environment,

and the type of degradation that

occurs.

A Compromise Used by Many Labs

• Use a QUV for most testing

• Use a small Xenon for color change.