Halar® ECTFEFluoropolymer Coatings for Cleanroom Exhaust Duct Systems

The choice for performance and safety

To protect your critical ductwork, specify Halar® ECTFE.

This guide is intended to clarify the advantages of Halar ECTFE overETFE for fluoropolymer coated duct applications. The informationcontained here summarizes the critical performance criteria requiredfor exhaust duct applications, as outlined in the table below.

Detailed information is available upon request.

Critical PerformanceCriteria Halar ECTFE ETFEFire Safety SUPERIOR Average

Surface Smoothness SUPERIOR Average

Permeation Resistance Equal Equal

Chemical Resistance Equal Equal

Hardness SUPERIOR Average

Adhesion SUPERIOR Average

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Halar ECTFE - A History of Success.A leading choice in semiconductor fabs.

Since 1990, Halar ECTFE powder coatings have been used successfully for corrosion protection of exhaust duct systems that must meet the FM4922 fire safety standard. In fact, Halar ECTFEwas the first fluoropolymer coating to gain approval and listing underFM4922 for Fume/Smoke Exhaust Duct Systems. Today, Halar is part of hundreds of duct system installations at more than 70 fabs worldwide.

In addition, Halar plastic sheet is used to meet FM4910 andUL2360 standards for fabrication of fire-safe cleanroom tools. And, seamless Halar powder coatings have replaced PVDF sheet linings in ultrapure water (UPW) systems (i.e., filter housing, ion exchangebeds, storage tanks).

Success in chemical processing applications.For over 20 years, Halar has also achieved exceptional results

in chemical processing applications. It is used extensively as a coating and/or lining material for exhaust duct, vessels, and process equipment.

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Superior fire safety properties of Halar ECTFE.

In response to industry-wide concerns about the fire resistance of all materials and components used in cleanroom process tools, the more stringent standards of FM4910, UL2360, and FM4922were established. These standards govern materials of construction for cleanroom equipment and exhaust duct systems.

Halar ECTFE can help you meet these standards, with performanceproperties for exhaust duct that include:

• FM4922 Listing• FM4910 Listing• Superior Limiting Oxygen Index (LOI)a – 60 for

Halar vs. 32 for ETFE• UL rated to 94 V0a LOI is used to define the level of oxygen needed to support combustion, according to ASTMMethod D2863.

In addition, Halar plastic sheet is FM4910 listed and meets theUL2360 Standard for Cleanroom Wet Bench and Tool construction.ETFE plastic sheet does not meet these standards.

High ignition resistance.As the table shows, Halar ECTFE is much more difficult to ignite

in the presence of an external heat source than ETFE.

Polymer Halar ECTFE ETFEAuto-ignition Temperatureb 655ºC (1211ºF) 500ºC (932ºF)

Critical Heat Fluxc (kW/m2) 74 16

SUPERIOR Average

b The lowest temperature for a combustible material to ignite in air without spark or flame. (ASTM D1929)

c Critical heat flux is a measure of the energy needed to start ignition. The higher the value, themore flame retardant the material. (ASTM E1354)

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Outstanding resistance to fire spread.

Halar ECTFE resists firespread better than ETFE. HalarECTFE forms a char to inhibitthe flow of molten polymer. By contrast, ETFE breaks downinto low molecular weight fragments that induce flow andcause fire dripping.

Within the Uniform BuildingCode (UBC), the ASTM E-84test is used to measure surfaceburning characteristics of buildingmaterials. Halar ECTFE coatedsteel panels are rated to a value of 5d which places it within ClassI of the safest materials in theUBC. ETFE coated steel panelswere rated 10. Halar consistentlymeasures one-half the value of ETFE in flame spread testing.

Halar ECTFE ETFEDemonstrating Halar’s superior resistance to fire spread. Testing done on powder coating grades compression molded.

d Reference: concrete = 0; red oak = 100

FM 4922 Test Temperature Measurement

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Coating thickness: Fire safety unaffected.Compared with ETFE, the flammability of Halar is relatively

unaffected by coating thickness, giving fabricators more flexibility in adding extra protection against corrosion and pinholes.

In FM4922 testing, ETFE coating with a thickness of 10 mil had a temperature of 950ºFe at the exhaust duct end, marginally meetingthe requirement of 1000ºF. Halar ECTFE, with a thickness of 12mil had a temperature of 625ºF at the exhaust duct end. This resultimplies that ETFE coating with a thickness greater than 10 mil willnot pass the FM4922 requirement.

Heat release data shown in the chart to right demonstrates thesuperior resistance to ignition and fire spread of Halar ECTFE coatingsversus ETFE coatings, regardless of thickness or energy source.

e As reported in competitor’s published data.

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Heat Release Comparison of Fluoropolymer Coatings

Properties of Halar Coated Ductwork.

Exceptional surface smoothness properties.As shown in the AFM images and calculated surface roughness (Ra)

values and AFM images, Halar ECTFE powder coated duct has amuch smoother surface than ETFE coated duct.

Benefits of a smoother surface include:

• Reduces the risk of pinholes in the coating• Inhibits buildup and accumulation of particles and metallic salts

These benefits result in better corrosion protection.

Surface smoothness parameters of fluoropolymer powder coatings.

Sample Halar ECTFE ETFE T1 ETFE T2 ETFE AMeanroughness(Ra), nm 21.93 59.99 63.77 53.67

SUPERIOR Average Average Average

Note: Results on actual powder coated samples.

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AFM Images of Powder Coatings

ETFE T2

ETFE T1 ETFE A

X 10.000 um/div

Z 1000.000 nm/div

Halar® ECTFE

Wide-ranging chemical resistance.

Halar coatings are resistant to solvents and acids/bases (pH 1–14). They have been used successfully for universal corrosion protection in the chemical processing industry since 1975.

In particular, Halar provides excellent resistance against these chemistries commonly encountered in exhaust duct:

• Hydrofluoric Acid (HF) • Piranha • Ammonium Hydroxide (NH4OH)• Sulfuric Acid (H2SO4) • Hydrogen Peroxide (H2O2) • All Alkaline Chemistries• Nitric Acid (HNO3) • Ozone (O3) • All Etchants and Strippers

Superior permeation resistance.

For chemistries encounteredin semiconductor exhausttools, Halar ECTFE providesexcellent permeation resistance.Because the chlorine atom in Halar ECTFE is larger thanthe fluorine atom in ETFE,the segments of the moleculeare more restricted in rotation.This reduced mobility, coupledwith Halar’s advantages in coating thickness, furtherenhance Halar’s permeationresistance.

The chart shows simple chemistries that are components of the more complex chemistriesfound in exhaust duct systems.

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Hardness of Fluoropolymer CoatingsPolymer Halar ECTFE ETFEShore D (ASTM D2240) D75 D67

Pencil Scratch Testf (ASTM D3363) 2B 6B

Cut throughg (ASTM D3032)

lbf (Newton) 54 (240) 46 (205)

SUPERIOR Average

f Determined by the lowest hardness of pencil to scratch the coating surface.g Measures the force required to cut a 0.25 mm thick coating down to wire with a specified blade.

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Adhesion Development Comparisonof Commercial Duct Coating Systems

Adhesion test conducted using coating conditions recommended by the resin manufacturer.Halar ECTFE is processed at 275ºC; ETFE at 315ºC. Primers are applied to developmaximum adhesion. The manufacturer of ETFE A recommends use of topcoat only.

Greater hardness.As illustrated in the table,

Halar ECTFE produces hardercoatings that are less prone toscratches and mechanical damagefrom sharp objects than ETFEcoatings.

Excellent coatingadhesion.

Halar ECTFE coatings provideexcellent adhesion, as demon-strated by film rupture in a peeltest. In fact, Halar ECTFEdevelops adhesion stronger andfaster than ETFE.

Between 23 to 50°C, thethermal expansion coefficient of Halar coating (8~10 x 105

mm/mm/°C) is lower than that of ETFE (12~15 x 105

mm/mm/°C). A lower thermalexpansion reduces the risk ofstresses between the coating andthe substrate that can accumulateduring the coating process,leading to longer service life.

USASolvay Solexis, Inc.10 Leonard LaneThorofare, NJ 08086 Tel: 856 853-8119Fax: 856 384-6126

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Brazil Solvay Solexis Ltda.Rua Urussuí, 300 - 4º andarCep: 04542-903 - São Paulo - SP-BrazilTel: 55 11 3708-5023/5181Fax: 55 11 3708-5115

FranceSolvay Solexis S.A.S.12, Cours Albert 1erF-753383 Paris Cedex 08Tel: 33 1 40758000Fax: 33 1 456 38226

GermanySolvay Fluoropolymers-A division of Solvay Advanced Polymers GmbHLudwigstrasse, 12D – 47495 RheinbergPostfach 101361D – 47493 RheinbergTel.: (49-2843) 73 2137 and 3627Fax: (49-2843) 732 143

Italy Solvay Solexis S.p.A.Viale Lombardia 20,I-20021 Bollate (MI), ItalyTel: 39 02 3835 1Fax: 39 02 3835 2129

United KingdomSolvay Solexis Ltd.Erico House 93/99Upper Richmond RoadPutneyLondon SW15 2TGEnglandTel: 44 208 7804000Fax: 44 208 7802871

JapanSolvay Solexis K.K.3F-Izumi Akasaka Building22-24 Akasaka 2-chomeMinatu-Ku, TokyoJapan 107Tel: 81 3 32247226Fax: 81 3 32247218

ChinaSolvay Beijing RepresentativeOffice2515, China World Tower 1n. 1 Jian Guo Men Wai AvenueBeijing 100004, ChinaTel: 86 10 65052280Fax: 86 10 65059389

Discover all the advantages.

For full details on how Halar ECTFE can helpimprove the safety and reliability of your criticalprocesses, call (800) 323-2874 or visitwww.solvaysolexis.com. Halar ECTFE ductworksystems are available worldwide.

To our actual knowledge, the information contained herein is accurate as of the date of this document.However, neither Solvay Solexis, Inc. nor any of its affiliates makes any warranty, express or implied,or accepts any liability in connection with this information or its use. This information is for use bytechnically skilled persons at their own discretion and risk and does not relate to the use of this productin combination with any other substance or any other process. This is not a license under any patent orother proprietary right. The user alone must finally determine suitability of any information or materialfor any contemplated use, the manner of use and whether any patents are infringed. This informationgives typical properties only and is not to be used for specification purposes.

Copyright 2003, Solvay Solexis, Inc. All Rights Reserved.