fine powders: a durable coating for durable products€¦ · rilsan® fine powders is a unique...

FINE POWDERS: A DURABLE COATING FOR DURABLE PRODUCTS

The statements, technical information and recommendations contained herein are believed to be accurate as of the date hereof. Since the conditions and methods of useof the product and of the information referred to herein are beyond our control, ARKEMA expressly disclaims any and all liability as to any results obtained or arising from anyuse of the product or reliance on such information; NO WARRANTY OF FITNESS FOR ANY PARTICULAR PURPOSE, WARRANTY OF MERCHANTABILITY OR ANY OTHERWARRANTY, EXPRESS OR IMPLIED, IS MADE CONCERNING THE GOODS DESCRIBED OR THE INFORMATION PROVIDED HEREIN. The information provided herein relates onlyto the specific product designated and may not be applicable when such product is used in combination with other materials or in any process. The user should thoroughlytest any application before commercialization. Nothing contained herein constitutes a license to practice under any patent and it should not be construed as an inducementto infringe any patent and the user is advised to take appropriate steps to be sure that any proposed use of the product will not result in patent infringement.See MSDS for Health & Safety Considerations.

The information contained in this document is based on trials carried out by our Research Centres and data selected from the literature, but shall in no event be heldto constitute or imply any warranty, undertaking, express or implied commitment from our part. Our formal specifications define the limit of our commitment.No liability whatsoever can be accepted by Arkema with regard to the handling, processing or use of the product or products concerned which must in all cases be employedin accordance with all relevant laws and/or regulations in force in the country or countries concerned.

4-8, cours Michelet92800 Puteaux - FranceTel.: 33 (0)1 49 00 80 80Fax : 33 (0)1 49 00 83 96www.arkema.com DI

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FOR ASIA

Arkema PTE LTD53 Tuas Crescent638732 SINGAPORE

Glenn BridgfordTel.: +65 64199019Fax: +65 [email protected]

FOR NORTH AMERICA

Arkema Inc.2000 Market StreetPA 19103-3222 PHILADELPHIAPENNSYLVANIAUNITED STATES

Neil LehmanTel.: +1 215 4197696Fax: +1 215 [email protected]

FOR EUROPE

Arkema4-8, cours MicheletLa Défense 1092091 PARIS-LA-DÉFENSE CedexFRANCE

Jan-Emmanuel TraënsTel.: +33 (0)1 49 00 71 37 Fax: +33 (0)1 49 00 50 [email protected]

www.rilsanfinepowders.com

Contents3 Introduction

4 - 5 Applications

6 - 7 Product range and properties

Range of powders

Recommended primers

Physical properties

Chemical resistance

8 - 9 Processing

Fluidized bed dip coating process

Electrostatic spraying process

Minicoat process

Other specialized coating techniques

10 Packaging

10 Environmental issues

10 Our global commercial

& technical service

2

Rilsan® Fine Powders is a unique synthetic thermoplastic

Polyamide 11 powder product range. It was developed for the first

time over fifty years ago to protect metal parts from corrosion.

Since then, Rilsan® PA11 coatings have fulfilled the most stringent

specifications of the industry thanks to their unique range

of properties, in a growing range of applications.

O R I G I N

Rilsan® PA11 is produced from a renewable raw material of plant

origin, the Ricinus Communis (Castor Oil), which grows primarily

in tropical countries.

Rilsan® Fine Powders is hence a thermoplastic which is not directly

impacted by the variation in crude oil prices.

Rilsan® Fine Powders are environmentally sound. They do not release

any volatile organic compounds, and their composition is free

of any heavy metal based pigments, and of curing agents.

They offer a responsible coating solution that helps safeguard

our environment.

A global chemical player,

Arkema combines 3 related and

integrated business segments:

Vinyl Products, Industrial Chemicals,

and Performance Products.

Present in over 40 countries with

18,400 employees, Arkema achieves

sales of 5.7 billion euros (2005).

With its 6 research centers in France,

the United States and Japan,

and internationally recognized

brands, Arkema holds leadership

positions in its principal markets.

Introduction

3

Results in a wide variety of applications due to a unique combination of properties

AUTOMOBILE

• Exceptional abrasion resistance

• Thermal and chemical resistance, including inertness to oils

• Flexibility and machining suitability

• Low friction coefficient

• Noise and vibration dampening

Spline shaftsSliding door and seat railsSprings, brackets, clips and safety belt fasteners

WIRE ARTICLES

• Very easy processing

• Excellent resistance to alkaline and chlorinated hot water

• Long-term abrasion and wear resistance

• Impact resistance

Dishwasher basketsShopping carts Various cleaning trolleys

Providing both aesthetic and functional properties, the Rilsan® PA11 coating offers a solution for the mostdemanding applications. The Rilsan® brand has become the reference around the world for the followingindustries looking for the ultimate metal protection:

4

5

FLUID TRANSFER

• High resistance to hydrocarbons and various chemicals

• Anti-corrosion properties

• Smooth surface for optimum flow

• Compliance with the most demanding specifications for contactwith drinking water (US, Europe, Japan). List of certified grades

• Very good resistance to wear and cavitation

• Good UV resistance

Pipes and fittings (drinking and waste water treatment plants)Valves, flanges, couplingsWater/hydrocarbon transportation pipelines, injection tubing

ROLLER INDUSTRY

• Exceptional resistance to wear

• Hardness designed for uniform pressure

• Smooth surface finish and low friction

• High resistance to inks and solvents

• Machining suitability, dimensional stability

Printing rollersRollers for textile, pharmaceutical and food industries

FOOD AND HEALTHCARE INDUSTRY

• Unique warm-to-the-touch and smooth surface

• Easy to clean, resistance to chemicals and heat

• Limitation of bacterial growth (Rilsan® Active)

Hospital furniture (beds, wheelchairs, etc.)Ambulance stretchersBathroom fittingsFood processing machinery

CLOTHING, BUILDING, ELECTRICALAND ELECTRONICS INDUSTRY

• Very easy processing

• Suitability for dyeing with colorants

• Aesthetic color tones

• Electrical insulation (low conductivity)

Undergarment and electrical industry (adjustors, bra wire, clips, etc.)Construction (nails, screws)

6

Product range and properties

RANGE OF POWDERS AND RECOMMENDED PRIMERS

RILSAN® T

T grades are designed for the fluidized bed dip coating process.A desirable coating thickness in between 250 to 500 µm can be achieved.

RILSAN® ES and RILSAN® ESY

This product range is designed for the electrostatic spraying process using positive,negative or “tribo” guns. Positive polarity is recommended for ES grades. ESY powders arespecially formulated with a built-in adhesion promoter to improve adhesion on the substrate,their processing requires no primer.

RILSAN® MC

MC grades are specially designed for the coating of small items via the minicoat/maxicoatprocess, which was originally developed by our company.

RILSAN® D

These powders are used as additive components for paint formulations.Rilsan® D provides excellent scratch and abrasion resistance, and the desiredstructural effect in a large range of liquid paints.

PRIMGREEN® AND RILPRIM®

High performance primers are marketed under the Primgreen® (water-borne, low VOC)and Rilprim® (solvent-based) brands. These primers have been specially developed

to be compatible with Rilsan® Fine Powders, on a variety of metal substrates andat various processing temperatures, to provide optimum anticorrosion properties when

combined with Rilsan® PA11 coatings.

Various products are currently marketed by Arkema under the following nomenclature:

The Rilsan® Fine Powders range has been constantly developing since it was first introduced. These powdersare available in many different particle size distributions and formulations to allow applicationby the standard powder coating methods used today. They are available in a wide variety of colors bothby the dry blend and the mass coloration process, which produces a stable finish and superior UV stability.Special grades and color-matched formulations can be developed specifically to suit customer needs.

7

PHYSICAL PROPERTIES OF RILSAN® COATINGS

* measured on natural and colored products

Properties Standard Units Values

Melting temperature ISO 11357 oC 186

Specific gravity ISO 1183, at 20 oC g/cm3 1.04 to 1.25*

Water absorption at saturation at 20 oC, 65% RH % 0.9 to 1.1at 20 oC, 100% RH 1.6 to 1.9

Surface hardnessShore D, ISO 868 Shore D 75Persoz, ISO 1522 sec 200 to 300

Abrasion resistance Taber, ASTM D4060 mg 15(CS17 grind wheel, 1000 cycles, 1 kg load)

Impact resistance ASTM G14 J 2 to 3

Salt spray resistance ISO 7253, on scribed primed plates mm < 1mm corrosion(testing according to WIS 4-52-01) after 2000 h

RESISTANCE OF RILSAN®

TO MAIN CHEMICALPRODUCTS

Rilsan® PA11 features outstandingresistance to oils, hydraulic fluids and fuels,

as well as excellent resistance to acids,bases and salts. The chemical resistanceof Rilsan® PA11 coatings is reflected both

in high dimensional stability under harshconditions and in the non-degradation

of the polymer matrix, making it the idealmaterial for highly demanding applications.

G = GoodL = Limited (swelling of Rilsan®-

suitability depends on specific use and duration)

For specific information,please refer to “Rilsan® Fine Powders -

Physical and Chemical Properties”.

Performance after 18 months’ exposure

Chemical agent Concentration Performance

20oC 40oC 60oC

Acetone Pure G G L

Agricultural spray G G

Ammonia Concentrated solutions G G G

Calcium chloride G G G

Citric acid G G L

Copper sulfate G G G

Fruit juices G G

Gasoil G G G

Glucose G G G

Glycerin Pure G G L

Greases G G G

Hydrogen G G G

Lactic acid G G G

Mercury G G G

Oils G G G

Ozone 2 ppm, 10 days G G

Paraffin G G

Petrol G G G

Sea water G G G

Sodium carbonate G G L

Sodium chloride Saturated G G G

Stearine G G G

Sulfur G G

Sulfuric acid 1% G L L

8

Processingof Rilsan® Fine Powders

Rilsan® PA11 coatings may be applied to all types of metal components, providing these can be raisedto the necessary coating temperature without causing any physical change to the metal (distortion)and degradation of its structure.

Processing is quite simple, and consists of depositing a Rilsan® film onto the metal surfaceneeding protection. The type of workpiece to be coated and the final properties required determine the bestapplication technique:

• dipping in a fluidized bed (T powders range);

• electrostatic spraying (ES, ESY powders range);

• dipping in a vibrating bowl (MC powders range);

• other specialized methods, i.e. hot-spraying or flame-spraying.

Whatever the coating technology, careful surface preparationis absolutely necessary beforehand if optimum performancehas to be achieved with Rilsan® products.Following this pre-treatment, a primer may be appliedto improve the adhesion of Rilsan® onto the surface,and maximize the anticorrosion properties. The use of a primeris particularly recommended when the coated parts aredestined for outdoor use and/or severe chemical or thermalenvironment, or in any demanding applications.

Rilprim® and Primgreen® primers, marketed by Arkema, undergoa full range of quality control tests prior to shipment to ourcustomers. By carefully following our recommendations on surfacepreparation and primer application*, our customers will obtainthe most outstanding and long-lasting properties from Rilsan® coatings.

* For further information on processing characteristics and properties, please refer to our

Technical Datasheets or contact our technical support teams for assistance.

Rilsan® PA 11 coating80 µm to several mm,

depending on the processPrimer

(for optimumadhesion)

Rilsan coatingPrimerSubstrate (steel, alu...)

Rilsan® coating system

Substratechemical pre-treatmentor mechanical cleaning

PRINCIPLE OF THE FLUIDIZED BED DIP COATING PROCESS

Advantages of the process:

• External and internal coatingin one single operation

• Uniform coating thickness achieved,even on parts with complex shapes

• High flexibility in terms of part dimensions

• Simple production technology

• Very good productivity

• Easy process automation

• Very little powder wastage

Pre-treatment Primer Pre-heating Dipping Cooling

9

PRINCIPLE OF THE ELECTROSTATIC SPRAYING PROCESS


• Good control over powder deposition

• Partial coating of the article canbe achieved

• Lower temperature during shorter timeto fuse the coating in the oven compared

to the pre-heating step in the fluidizedbed coating process*

• No crosslinking risk comparedto thermoset materials

• Smaller powder stock required

• Process may be automated

* Depending on the desired coating thickness and the nature of the metal, the time and / or

temperature in the oven may vary. For further information, please refer to the Technical Datasheets

on the processing of Rilsan® Fine Powders.

PRINCIPLE OFTHE MINICOAT PROCESS

Arkema has developed a process under the name“Minicoat” for the coating of small articles, whichcan vary from less than 1 cm to approximately 15 cmin overall size. Its principle is similar to the fluidizedbed dip coating process: a small pre-heatedarticle is dropped into a Rilsan® vibrating bowl,and the powder immediately melts onto the surfacethanks to the residual heat in the article.The surface finish can subsequently be smootheddown using a post-fusion oven.


• Fully automated process

• No need for suspension points during the operation,no jig marks after coating

• Highly uniform thickness

• Easy control of the final aesthetic appearance(smooth or textured)

• Outstanding productivity,successful coating of thousands

of parts per hour

OTHER SPECIALIZEDCOATING TECHNIQUES

In addition to the conventional dipping in fluidizedbed and electrostatic spraying coating technologies,both widely used throughout the world, Arkema hasdeveloped new technologies and adapted productformulations over the last 20 years to provide efficientcoating systems for specific applications.

Rilsan® Fine Powders are aptly suited to mostother standard processes dedicated to powder coatingmaterials: hot (flock) spraying, rotomolding,pipe lining, flame spraying, etc., to name but a few.

Such processes are particularly adapted tothe coating of large or bulky parts (valves, pumps,cylinders), articles with intricate designs (heaters),or large diameter pipes designed for the transportationof highly abrasive slurries, which are too large tobe dip-coated.

Depending on the final coating properties required,both the processing conditions and the gradescompatible with such technologies should be studiedand chosen specifically. Our technical support teamwill be pleased to assist you further in this regard.

Pre-treatment Primer Spraying Fusion

10

PackagingRilsan® Fine Powders are supplied in 20 or 25 kg sealed bags or 850 kg octabins.The bags consist of a multilayer Kraft paper/PE, which ensures mechanical resistance,efficient palletization, and a high barrier to moisture.Every Rilsan® Fine Powders bag carries appropriate labels with all essential data (product name,article code, batch number) for traceability purposes.

Environmental issuesRilsan® Fine Powders offer many positive features in terms of environmental protection, in line with Arkema’sglobal initiatives on sustainable development.

Produced from Castor Oil, Rilsan® polyamide 11 Fine Powders are made of 100% renewable raw material.Through its ongoing purchase of Castor Oil on the world market, Arkema contributes to the developmentof several regions (South America, India, South-East Asia, China).

Rilsan® Fine Powders applications afford an unrivaled balance of technical and economic benefitsthroughout the industrial supply chain down to the end-consumer.The use of Rilsan® Fine Powders as a coating for dishwasher baskets, for example, combines outstandingresistance to chemicals and long-term corrosion protection, with ease of processing and quickassembly of coated parts, thereby ensuring absolute competitiveness to job-coaters using Rilsan® coatingsin the appliance industry.

Arkema’s global commercialand technical serviceMarketed by Arkema’s Technical Polymers Business Unit, Rilsan® Fine Powdersboast a global and integrated organization in terms of marketing, technicalsupport, and development network. The Technical Polymers Business Unitwill be pleased to assist you at any stage of projects involving the useof Rilsan® Fine Powders (design, industrial development, market launch).

Technical coating centers have been set up in France, Japan and the USto provide first-rate technical assistance to our existing customers.Our technical support teams specializing in high-performance polyamidematerials (choosing the right product, processing, applicationdevelopment) can help you develop high-tech solutions, while advisingon the various issues that ensure the economic viability of your project.

As a long-standing partner to high-tech industries, we can oversee complexdevelopments involving the end-user and the industrial supply chain (job-coatersand original equipment manufacturers).

FINE POWDERS: A DURABLE COATING FOR DURABLE PRODUCTS

The statements, technical information and recommendations contained herein are believed to be accurate as of the date hereof. Since the conditions and methods of useof the product and of the information referred to herein are beyond our control, ARKEMA expressly disclaims any and all liability as to any results obtained or arising from anyuse of the product or reliance on such information; NO WARRANTY OF FITNESS FOR ANY PARTICULAR PURPOSE, WARRANTY OF MERCHANTABILITY OR ANY OTHERWARRANTY, EXPRESS OR IMPLIED, IS MADE CONCERNING THE GOODS DESCRIBED OR THE INFORMATION PROVIDED HEREIN. The information provided herein relates onlyto the specific product designated and may not be applicable when such product is used in combination with other materials or in any process. The user should thoroughlytest any application before commercialization. Nothing contained herein constitutes a license to practice under any patent and it should not be construed as an inducementto infringe any patent and the user is advised to take appropriate steps to be sure that any proposed use of the product will not result in patent infringement.See MSDS for Health & Safety Considerations.

The information contained in this document is based on trials carried out by our Research Centres and data selected from the literature, but shall in no event be heldto constitute or imply any warranty, undertaking, express or implied commitment from our part. Our formal specifications define the limit of our commitment.No liability whatsoever can be accepted by Arkema with regard to the handling, processing or use of the product or products concerned which must in all cases be employedin accordance with all relevant laws and/or regulations in force in the country or countries concerned.


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FOR ASIA

Arkema PTE LTD53 Tuas Crescent638732 SINGAPORE

Glenn BridgfordTel.: +65 64199019Fax: +65 [email protected]

FOR NORTH AMERICA

Arkema Inc.2000 Market StreetPA 19103-3222 PHILADELPHIAPENNSYLVANIAUNITED STATES

Neil LehmanTel.: +1 215 4197696Fax: +1 215 [email protected]

FOR EUROPE

Arkema4-8, cours MicheletLa Défense 1092091 PARIS-LA-DÉFENSE CedexFRANCE

Jan-Emmanuel TraënsTel.: +33 (0)1 49 00 71 37 Fax: +33 (0)1 49 00 50 [email protected]


WHAT IS A SURFACE PRETREATMENT?A surface treatment includes the necessary steps that preceed theapplication of a Rilsan® powder coating on the substrate to be protected.The purpose of the pretreatment stage is twofold. First, it has to eliminateall impurities from the surface prior to coating. Second, one or moreprotective undercoats can be applied to obtain a high-quality coating andachieve optimum performance. The lifetime of the protective coating verymuch depends on the quality of the preliminary surface treatment.

The nature and shape of the metal part, as well as the conditions (thermal,chemical and atmospheric) to which the parts will be subjected, are themain factors that should guide coaters in choosing the most suitable,i.e. mechanical or chemical, surface treatment.

Two types of products are available on the market for use as undercoatsfor Rilsan® coatings: Rilprim® and Primgreen® liquid primers.

OPERATING CONDITIONS Degreasing

This essential step is designed to eliminate fatty substances that build upon the surface during the manufacturing of the metal part. It requires theuse of alkaline, neutral or acidic products (depending on the nature of thegrease to be eliminated, and the nature of the metal) that may beapplied by spraying or dipping. More universal solvent-based solutions(trichloroethylene, perchloroethylene) may also be used.

In order to eliminate grease from large steel (or ferrous alloy) parts, high-temperature pyrolysis can be utilized where the metal structure allowsit. In other cases, the coater may recommend manual cleaning if it ismore appropriate.

A visual examination will help confirm the absence of grease or pollutionon the surface of the part.

Stripping / Grit-blasting

This stage follows the degreasing step and eliminates all foreign bodies(e.g. carbon impurities or metal oxides) present on the surface of the part.Once the surface is free of oil and grease, the following process may becarried out:

• mechanical etching involves blasting the part surface with an abrasivemedium. Type G17 angular shaped iron grit or corundum is recommendedfor ferrous metals, and aluminum grit for aluminum alloys. The blastingair should be dry and free of oil. Once it has been grit-blasted, the partshould be coated without delay (generally within 8 hrs), or it may temporarilybe kept dry to prevent the formation of oxides on the surface. Should signsof surface corrosion appear, the grit-blasting stage must be repeated beforethe coating can be applied.

• chemical etching involves immersion or spraying the part with strongacidic solutions (sulfuric, hydrochloric or phosphoric acid), followed byconsecutive rinsing and drying in stable and controlled chemical baths.Other types of chemical treatment (e.g. electroplating, phosphating,chromating, etc.) may be used as long as they are compatible with theRilsan® PA11 coating and its application process.

Quality grit-blasting should produce a thoroughly clean surface (Sa 2 1/2-3)and roughness Rz (measured per standard ISO 4287-1) generally rangingfrom 40µm to 80µm when Rilsan® is applied by dip-coating, and from 20µmto 40 µm when Rilsan® is applied by electrostatic spray. The surfaceroughness may need to be adjusted to achieve the right properties requiredin certain applications, based on the nature of the metal used.

WHAT IS THE PURPOSEOF A PRIMER UNDERCOAT?A primer undercoat creates a chemical bond producing strong adhesionbetween the substrate to be protected and the Rilsan® coating. It alsoensures durable protection against corrosion should the coating bedamaged. Arkema markets a range of solvent-based (Rilprim®) and water-based (Primgreen®) liquid primers. Primgreen® has a low volatile organiccompounds (VOC) content, is particularly environmentally sound, and isvery easy to use.

Primer for Rilsan® DIP-COATING (e.g. Primgreen® LAT12035)This one-component product can be applied by spray-gun using a traditionalspraying techniques (compressed air or electrostatic). Under normaltemperature and moisture conditions, the viscosity of the product issuch that the product does not need to be diluted. Dip-coating is alsopossible: in this case, the product should be diluted with a water/butylglycol (3:1) blend to achieve a 60/40 product/diluting blend ratio by volumeprior to application.

Precautions required:

It is necessary to apply, over the entire surface, a continuous and consistentlythick film (8 to 12 µm dry film) on every part coated. Consult the primerdata sheet to ensure that the proper drying time is observed before theprimer is cured in an oven. These factors and the preheating parametersof the part, determine the quality of the primer’s curing (characterizedby a brown color after curing), and conditions the quality of the Rilsan®

coating’s final properties.

The curing conditions (time/temperature) necessary to achieve optimumadhesion properties depend on the nature and thickness of the part.These conditions should be determined by the coater for every type of partbased on the equipment available.

The chart below, as an example, indicates the optimum range of use forPrimgreen® LAT 12035 on a 6mm thick metal part. This range is a functionof the preheating and oven temperature and time parameters. Adhesionproperties exceeding or equal to 3 as per standard NFT 58-112 are foundin the area colored in blue.

Surface treatments and primersfor Rilsan® PA11 coatings

80

70

60

50

40

30

20

10

0

280 290 300 310 320 330 340 350 360 370

Temperature of the metal (oC)

Recommended rangeof use for PRIMGREEN® LAT 12035

Temperature holding time for the metal (min)

Working rangeas per Adhesion NFT 58-112 equals to 3

6 mm metal part1 min between removal from the ovenand dip coatingAmbient temperature in the workshop


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The statements, technical information and recommendations contained herein are believed to be accurate as of the date hereof. Since the conditions and methodsof use of the product and of the information referred to herein are beyond our control, ARKEMA expressly disclaims any and all liability as to any results obtainedor arising from any use of the product or reliance on such information; NO WARRANTY OF FITNESS FOR ANY PARTICULAR PURPOSE, WARRANTY OF MERCHANTABILITYOR ANY OTHER WARRANTY, EXPRESS OR IMPLIED, IS MADE CONCERNING THE GOODS DESCRIBED OR THE INFORMATION PROVIDED HEREIN. The information providedherein relates only to the specific product designated and may not be applicable when such product is used in combination with other materials or in any process.The user should thoroughly test any application before commercialization. Nothing contained herein constitutes a license to practice under any patent and it shouldnot be construed as an inducement to infringe any patent and the user is advised to take appropriate steps to be sure that any proposed use of the product willnot result in patent infringement. See MSDS for Health & Safety Considerations.

The information contained in this document is based on trials carried out by our Research Centres and data selected from the literature, but shall in no eventbe held to constitute or imply any warranty, undertaking, express or implied commitment from our part. Our formal specifications define the limit of our commitment.No liability whatsoever can be accepted by Arkema with regard to the handling, processing or use of the product or products concerned which must in all casesbe employed in accordance with all relevant laws and/or regulations in force in the country or countries concerned.


CHOOSING THE RIGHTPRIMER UNDERCOATThe choice of the right undercoat depends on the nature of the substrateto be protected (steel, cast iron, stainless steel, aluminum, etc.), the levelof performance sought, and the process selected to apply the Rilsan® PA11powder.

If you require further information, please contact our technical supportteam and they will be pleased to assist you with choosing the right product.

Undercoats other than Rilprim® and Primgreen® may be suitable and meetthe necessary specifications. Such products should be evaluated beforehand.

However, only Rilprim® and Primgreen® marketed and recommended byArkema undergo systematic performance testing, so that our customersmay be assured of a top quality product.

Primer for Rilsan® ELECTROSTATIC SPRAY(e.g. Rilprim® LES 201/104 B)

Suitable for application by traditional spraying or electrostatic spraying,this solvent-based two-component product consists of a resin (Rilprim®

LES201) and its dilutant (Rilprim® 104B) mixed in 50/50 proportions byvolume. Applied in a thin coat (5 to 8µm dry film), this primer undercoatis compatible with Rilsan® powders applied by electrostatic spray. The curingof the primer occurs during the melting phase of Rilsan® ES or ESY powders.

Rilprim® LES201 is a Cr+6 free formulation. It helps produce excellentanticorrosion properties (no loss of adhesion and no corrosion creep after2000 hrs’ exposure to a salt spray or 2000 hrs in boiling water). This productis recommended for the most demanding applications on steel.

Rilsan® PA 11 coating 80 µm to several mm,

depending on the process

Substratechemical pretreatmentor mechanical cleaning

Rilsan coatingPrimerSubstrate (steel, alu...)

Rilsan® coating system

Primer(for optimum adhesion)

Nature Range of Primers concerned Cause

Poor wetting Primgreen® • Part too greasy

• Drying time too long• Temperature of metal too low• Ambient temperature too low, or ambient

Rust on the part (“flash rust”) Primgreen®

humidity too high• Primer coating too thick• Insufficient air extraction from the booth

Uneven film Rilprim® & Primgreen® • Presence of dust on the surface

Drops and runs Rilprim® & Primgreen® • Too much primer

Bubbles Rilprim® / Primgreen® • Product not stirred properly

PRIMERS: MAIN APPLICATION DEFECTS AND THEIR POSSIBLE CAUSES

Dip coating in a fluidizedbed of Rilsan® Fine Powders

PRINCIPLE OF THE PROCESSDip-coating in a fluidized bed consists in immersing a heated part in apowder bed maintained in suspension through rising air flow. As soon asthe Rilsan® powder comes into contact with the preheated article, it meltsand forms a film on the surface of the component. This process producesa consistent thickness, even on parts with complex profiles (internal andexternal coatings in one operation). The dip-coating process is efficient(very little powder wastage) and straightforward.

The Rilsan® T range has been developed specifically for this technology.

CRITERIA FOR CHOOSINGTHIS PROCESSA desire to simplify the coating process will guide the customer towardthe dip-coating technology, combining excellent productivity withperfect thickness control. Applying Rilsan® by dip-coating can easily beautomated. The choice of this process depends on the following criteria:

Thickness of the part:

the process is particularly suitable for bulky or massive parts (metalthickness of at least 3 mm). For small diameter wire articles, a post fusionoperation may be required following the dip-coating operation.

Thickness of coating:

the process allows the application of Rilsan® coatings with a thicknessgenerally ranging from 250 to 500 µm. For very bulky parts, it is possibleto apply thicker coatings by increasing dipping time, or by carrying outseveral consecutive dipping operations.

Size of the part:

the dimensions of the part determines the size of the tank. Very heavy orvery long components (tubes) can be coated by this method, but will requirespecific handling equipment.

Nature of the support - surface treatment:

the process is suitable for any type of material that can withstand thenecessary oven preheat temperatures. Massive parts will require a preheattemperature of around 300 oC while thinner parts require preheattemperature up to 400oC.

OPERATING CONDITIONS Surface treatment - Primer

The parts to be coated should be clean, and completely free of grease or oil.It is often necessary to apply a primer undercoat specifically compatiblewith Rilsan® dip-coating grades in applications requiring the most exactingperformance, e.g. the transportation of drinking water, or in the automobilesector. The choice of primer depends on the nature of the material tobe coated.

For further information, please refer to the Technical Datasheet on “SurfaceTreatments and Primers compatible with Rilsan® PA11 coatings”.

Type of equipment

• Fluidizing tank: preferably in stainless steel, it should consist of 2 partsseparated by a porous plate made from polyester fabric. The air used forfluidization should be cold, clean and free of oil, and should be generatedby an electric compressor in the case of large tanks. The temperature ofthe Rilsan® powder during fluidization should not exceed 60oC. Specialfluid beds can be made that will keep the powder cool by circulating coldwater through jacketed walls.

• Environment and processing conditions: an air exhaust should beinstalled near the top of the tank to capture dust particles that couldcontaminate the immediate environment (oven). Personal protectiveequipment such as a dust-mask is also recommended. The safety datasheetcontains information on proper handling of the product.

• Preheating oven: a forced air circulation (6 m/s) oven is recommended.The oven should have a temperature controller and a vent with a fumeextraction device. A batch oven (with one or more doors) or a tunnel typeoven with component conveying may be used based on the type of workrequired.

Applying the coating

• Preheating conditions: to obtain a high quality Rilsan® coating overthe entire surface, the temperature of the part should be as even as possible,around 280oC - 300oC at the time of dipping. The preheating temperatureand time are determined respectively by the minimum and maximumthickness of the part to be coated. For example, the time needed to heata 3mm thick steel plate up to 300 oC is typically minimum 10 minutes.

• Dipping: the preheated part is dipped into the fluidized powder bed.Dipping time generally ranges from 3 to 5 seconds. To ensure good penetrationof the powder, it is vital to move the part around during dipping to preventthe formation of coating defects.Most parts should be allowed to air cool. However, thinner parts can becooled by quenching in water after the coating is no longer molten.

• Masking: it is possible to locally mask areas that do not require coatingby using wirewool for internal sections, and adhesive tape or a specialpaste for external sections.

• Handling and touch-up of the parts: the jig or hanger should be fastenedto the part to allow good movements (shaking) of the part, for properapplication of the coating. Where possible, it is preferable to attach thehanger to an area of the part that does not require coating. Hangermarks can be touched up with an epoxy or polyester resin.


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Nature Cause

• Inadequate preparation of the surfacePoor adhesion • Too little or too much primer

• Wrong preheating temperature and/or time

• Degassing of partBubbles • Primer coating too think

• Air inclusion due to excessively long dipping time

Cluster • Poor fluidization of the powder• Insufficient or inadequate motion during dipping

• Contaminated powderBlack spots • Presence of impurities around the tank

• Pollution in post-fusion oven

• Preheating temperature too highYellowing • Preheating time too long

• Dipping time too short

• Insufficient shaking during dippingPinholes at intersection of faces or wires • Preheating temperature too low

• Dipping time too short

• Preheating temperature too high

Poor edge coverage • Dipping time too short• Post-fusion temperature too high• Post-fusion time too long

• Preheating temperature too low• Preheating time too short

Frosting or unmelted powder • Excessive delay between preheating and dipping• Dipping time too long• Insufficient shaking after dipping

RILSAN® T: MAIN APPLICATION DEFECTS AND THEIR POSSIBLE CAUSE

Electrostatic sprayingof Rilsan® Fine Powders

PRINCIPLE OF THE PROCESSElectrostatic spray coating consists of depositing electrically chargedpowder particles on the surface of the metal to be coated at ambienttemperature. The electrostatic charge is obtained by blowing the powderthrough a spraying device (such as “corona” or “tribo” spray-guns).The charged powder particles are attracted to the grounded part to becoated. The powder coated part is then moved into an oven where the Rilsan®

powder fuses to produce a smooth and non-porous coating.

Two series of Rilsan® grades are suitable for this application process:the Rilsan® ES and Rilsan® ESY ranges, ES grades requiring the priorapplication of a suitable adhesion undercoat (primer).

CRITERIA FOR CHOOSINGTHIS PROCESSThe electrostatic coating process gives flexibility to the coater. The processcan be automated for high speed, coating thickness is easy to regulate,and masking sections of parts, so they are not coated, is no problem.The choice of this process depends on the following criteria:

Thickness of the part:

the process is perfectly suited for coating thin parts as well as parts asthick as 6 mm.

Thickness of coating:

the process allows controlled thickness ranging from 80 to 120 µm(Rilsan® ESY grades), and from 100 to 150 µm (Rilsan® ES grades).

Size of part:

there is no limit to the dimensions of the part to be coated; partial coatingis possible.

Nature of part - surface treatment:

the process is suitable for all types of conductive metal substrates capableof withstanding a temperature of 220°C without deterioration.

OPERATING CONDITIONS Surface treatment

The parts to be coated should be clean, and free of grease or oil.For further information, please refer to the Technical Datasheet on “SurfaceTreatments and Primers compatible with Rilsan® PA11 coatings”.

Primer

For Rilsan® ES grades, it is recommended to apply a primer to preventelectrostatic discharge and the powder falling off during fusion. The primerpromotes the adhesion of Rilsan® onto the surface of the metal to beprotected, and helps achieve outstanding anticorrosion performance aswell as excellent resistance to hot water.

For further information, please refer to the Technical Datasheet on “SurfaceTreatments and Primers compatible with Rilsan® PA11 coatings”.

Powder spraying

• Equipment typeRilsan® ES grades require the use of spraying equipment either of thecorona type with positive polarity (from + 30 to + 40 kV) or the tribo type.Rilsan® ESY grades should only be applied using the corona process withnegative polarity (from - 30 to - 70 kV).

It is possible to recover the fraction of Rilsan® ES powder that has notcoated the component, and to blend it with virgin powder after sieving andremoving its electrical charge. It is not advisable to recycle Rilsan® ESYpowders if optimum quality is required from the product. However,production trials may be carried out to establish recycling feasibility.

• Powder spraying environmentThe formulation of Rilsan® powders makes them insensitive to pollutioncraters. However, it is necessary to ensure that both the coating equipmentand the work environment are clean in order to minimize pollution fromdusts generated during the coating process.Ideal conditions for electrostatic spray coating using Rilsan® powdersinclude temperatures ranging from 20oC +/- 5oC and air humidity levelsclose to 50%.

When handling the product, users are advised to refer to the product’ssafety datasheet and to current regulations on the use of powder coatings.

Fusion

•Oven typeFusion should occur in a perfectly temperature-controlled oven(homogeneous temperature throughout) with good ventilation (air speedtypically below 3m/sec) in order to prevent air blowing too fast around thecoated parts. Tunnel type ovens are most suitable for continuous processing.

•Fusion temperature / timeUnlike thermoset powders, Rilsan® powders do not crosslink: surfacetemperatures of 215oC +/- 5oC allow PA11 thermoplastic to melt, and theproducts’ properties are reached as soon as the film formation is achieved.The time needed to melt the powder and cool the coating depends onthe thickness and configuration of the part. For a smooth ZES steel part, the residence time in the oven needed to melta Rilsan® coating is shown on the following graph, as an indication:

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Nature Cause

• Too much powder applied• Excessive humidity of powder or coating equipment air supply

Bubbles • Degassing of support• Too much primer applied• Oven temperature too high

• Fusion time or temperature too low

Orange peel• Distance between spray-gun and part too short• Application tension too high• Ambient temperature too low

Pinholes • Coating thickness too small (too low powder flow or insufficient spraying time)• Support not clean enough

Frosted or unmelted powder • Fusion time too short or fusion temperature too low

Yellowing • Fusion temperature too high or fusion time too long

• Inadequate preparation of the surfacePoor adhesion • Too little or too much primer

• Inadequate baking temperature and/or time

• Inadequate preparation of the surface • Too much powder

Adhesion failure • Oven ventilation too strong• Too little primer• Application tension too low

RILSAN® ES: MAIN APPLICATION DEFECTS AND THEIR POSSIBLE CAUSES

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