Powder Coating Anticorrosion Primers for Steel

Atmospheric Corrosion on Steel

What is corrosion?Corrosion is the deterioration of a material due to chemical or electrochemical reaction resulting from exposure to severe weather, due to humidity, to chemical products or to other agents present in the environment in which the material is located. This is simply a case of a metal in the

process of naturally returning to its oxide condition.

Analysis of rustThere is no standard for visual assessment of rust. In general, laboratories

conduct a more or less subjective assessment, such as the following one:

Light rust Moderate rust Severe rust

Categories of Corrosiveness

Identifying the corrosiveness of the environment The rate of corrosion of a steel substrate exposed either indoors or outdoors will vary depending on the level of corrosiveness of its environment. The more aggressive an environment, the higher the rate at which corrosion will develop.

Standard ISO 12944-2 specifies the categories of corrosive atmosphere and environment that are used to define appropriate protection systems.

C5-M C1

C2

C3C4

C5-I

Category of corrosiveness

Outdoor Indoor

C1 Very Low Buildings that are heated by their own internal

atmosphere, for example: offices, shops, schools, hotels.

C2 Low Atmospheres with a low pollution level. Mainly rural areas.

Non-heated buildings that have a risk of condensation, for example: warehouses or sports halls.

C3 AverageUrban and industrial atmospheres, moderate pollution from sulphur dioxide. Coastal areas with low salinity.

Production shops with a high content of humidity and low air pollution, such as foodstuffs industries, laundries, breweries or dairies.

C4 High Industrial and coastal zones with moderate salinity. Chemical works, swimming pools and maritime/naval yards.

C5-I (Industry) Very high

Industrial zones with a high humidity level and an aggressive atmosphere.

Any buildings or zones with continuous condensation and high pollution.

C5-M (Marine) Very High

Coastal and maritime zones with high salinity. Any buildings or zones with continuous condensation and high pollution.

Our Solutions against Corrosion on Steel

The above information is based on our experience gained with AkzoNobel Powder Coatings, and does not incur any responsibility for AkzoNobel. Please consult us in order to gain advice appropriate to each specific requirement. And please note that a durability range is not a “guarantee period”: rather, it is an item of technical information on the basis of which it is possible to select a system and/or establish a maintenance program. Regular maintenance of treated components will maximize durability.

Guide for selection of Interpon Anticorrosion on steel, set out according to categories of atmospheric corrosiveness

Principle System Surface Treatment C1 C2 C3 C4 C5-M C5-I

Passivation Interpon APP 120 + Interpon DMechanical

Chemical

Barrier effect Interpon BPP 600 + Interpon DMechanical

Chemical

Cathodic protection(double layers)

Polyzinc 790 + Interpon D Mechanical

Cathodic protection + barrier effect

Polyzinc 790 + Interpon BPP 330 + Interpon D Mechanical

Durability <5 years Durability 6-10 years Durability 11-15 years Durability >15 years

Stage 1Raw components as received

Stage 2Components treated by shot blasting Sa ≥ 2,5

Stage 3Shot blasted components ready for powder coating

Example of pre-treatment: mechanical pre-treatment

Active Protective Primer Interpon APP 120

Protection by passivation of steelPowder coatings make it possible to delay the infiltration of corrosion underneath the coating, using corrosion-inhibiting pigments which have the capacity for passivating the steel substrate.

This technology is used to slow down the rate of reaction with the water/oxygen mix, or to neutralise the acid ions caused by humidity.

Areas of use• Components with machined edges produced by stamping, shearing, sawing

or drilling, or by thermal cutting. The expected levels of protection can be achieved only by careful compliance to levels of preparation P1/P2/P3 according to ISO 8501-3,

• Agriculture equipment,

• Metal frameworks,

• Steel artworks (please consult us),

• Guard-rails,

• Public lighting systems,

• Shutters.

Characteristics and advantages• Excellent edge coverage after surface pre-treatment with a suitable level

of preparation,

• Primer can be available in specific colors (on request),

• Can be used as a holding primer,

• Good anti-corrosion performance especially where passivation is used as a pre-treatment,

• Can be coated with Cromadex liquid paints 1K or 2K PU types, as an alternative to Interpon powder coatings.

Primer indicative color / Interpon code EL140G

Photo A 8 mm steel component, treated with oxygen laser cutting

Photo B Complete system: APP120 + RAL 2002 topcoat. Overall thickness: 150±10µ

A

B

Barrier Protective Primer Interpon BPP 600

NEW

Protection by barrier effectThe purpose of this technique is to isolate steel from its environment by protecting it with a water-proof, air-proof covering such as an enamel, a coat of paint, a plastic coating etc.

This is referred to as barrier effect protection.

Oxygen and other corrosive agents are prevented from making direct contact with the steel, and consequently no corrosion can form.

Areas of use• Fixed components that are subjected to low humidity

• Items of industrial equipment

• Garden furniture, street furniture

• Signboards

• Gas bottles and tanks

• Guard-rails

Characteristics and advantages• Excellent adhesion to steel substrate

• Excellent anti-corrosive properties

• Very wide curing range (refer technical data sheet)

• Good resistance to chemical attack

• Can be used as a holding primer for one week maximum

• Can be overcoated with Cromadex PU 1K or 2K type liquid paint as an

alternative to Interpon power coating

Primer indicative color / Interpon code AL251F

Topcoat (liquid or powder paint)

Barrier effect

Zinc Rich PrimerInterpon PZ 790

Protection of steel by Duplex systemA zinc layer or one that contains zinc, coated with a liquid or powder-form coating, is called a Duplex system.

This two-coat system combines the cathodic protection afforded by zinc with the protection that the outer coating provides. Interpon PZ 790 is intended for

protection of ferrous metals, apart from any zinc spray processed steel.

Performance of Interpon PZ 790• Photo A :

shot blasting sa ≥ 2.5 + single coat of Interpon D with no primer

• Photo B : shot blasting sa ≥ 2.5 + Polyzinc 660 primer + Interpon D topcoat

• Photo C : shot blasting sa ≥ 2.5 + Polyzinc 790 primer + Interpon D topcoat

Characteristics and advantages• Very high anti-corrosion protection, especially in conjunction

with shot blasting,

• Very high quality of finish compared with other metallic zinc based protection solutions which are usually characterised by a rough, porous surface that causes bubbling in the cladding,

• Excellent finish, combined with ease of application,

• A network of approved applicators ensuring right level of quality and performance,

• Zinc primer.

SCAB test: Results after 24 months natural, forced exposure. (at Segé, near Malmö in Sweden, 4 km from the Baltic Sea coast, Preparation by shot blasting, sa 2.5, Ra 6-7µ).

Primer indicative color / Interpon code ALZ90F

A B C

Dirickx gate protected by Duplex system (Polyzinc 790 + RAL topcoat)

Interpon powder topcoat

Polyzinc 790

Steel Zinc salts

Zinc Rich Primer Interpon PZ 790

Protection of steel with Triplex systemInterpon PZ 790 + Interpon BPP 330 + the top coat system is recommended in highly-aggressive environments. This three-coat system is made up of Interpon PZ 790 zinc rich primer, the barrier effect primer BPP 330 and a polyester topcoat for outdoor use or an epoxy/polyester topcoat for indoor.

Areas of use• Architecture,

• Guard-rails,

• Fencing,

• Steel structures,

• HGV bodies and chassis,

• Gas tanks.

Valence – Spain, Davis Chipperfield Architects Built for the Americas Cup. This seaside building is protected with a triple-coat system: Interpon PZ + BPP 330 + D 1036.

Process for application of double-layer and triple-layer system

Polyzinc 790 indicative color / Interpon code ALZ90F

BPP 330 primer guideline color / Interpon code AL113D

3rd coat : Interpon D topcoat paint

Raw steel surface

SA 2.5 shot blasted steel

1st coat : Polyzinc 790 primer

2nd coat : BPP 330 primer

2

3

4

55

1

Areas of use• All porous substrates,

• Zinc spray processed steel,

• Zamak,

• Cast steel and aluminum,

• Zinc electro-plated steel,

• Hot-dipped galvanised steel.

This polyester epoxy based primer was designed for direct application on

substrates that are susceptible to out-gassing.

Characteristics and advantages• Application of powder coatings on porous substrates (hot dip

galvanized steel, cast components, metal spraying) will very often entail an out-gassing phase before application of anti-corrosion primer (at a temperature 20°C higher than is recommended for the topcoat).

• APA 151 enables application directly on to the substrate without prior out-gassing. By virtue of its formula, which enables a delay in the cross-linking of the paint film, resulting in a reduction of unwanted bubbling.

• Does not require pre-heating prior to powder coating.

• It can be coated with any of our Interpon D topcoats.

• APA 151 also has excellent performance in covering ridges.

APA 151 on hot galvanised steel, total bake.

Primer indicative color / Interpon code FL151F

Anti-gassing primer Interpon APA 151

Out-gassing substrate

APA 151

Topcoat of Interpon D powder

Release of oxygen particles

Interpon finishes and topcoats

Interpon anti-corrosion primers can be coated with a wide range of colours and effects such as:

• Structure of the film : smooth, hammered, fine or coarse textures.

• Gloss : glossy, satin, matt.

• Color : unlimited range of shades.

• Effects : Chiné (salt & pepper), metallic, pearlescent.

Ask for a free-of-charge color chart for Anodic, Brilliance, Collection Futura and Structura ; on our website www.interpon.com or contact your local AkzoNobel representative.

Series Purpose Typical use Benefits

Interpon 700 Indoor protection and decoration.Metal furniture, storage units, shelving, indoor light fittings, electrical appliances, convector heaters, industrial equipment, automotive.

Good indoor performance over prolonged periods. Wide range of available finishes.

Interpon 610Protection and decoration of outdoor industrial items.

Street furniture.Good resistance to bad weather, good resistance to UV.

Interpon D1036

High-performance outdoor protection and decoration for architectural use. Standard Durability.

Metal fittings, frontages, verandas, doorways, metal doors & blinds, sunshades, garage doors, outdoor light fittings, fences.

Excellent durability in outdoor atmospheres.

Interpon D2525High-performance outdoor protection and decoration for architectural use. Super Durability.

Metal fittings, frontages, verandas, doorways, metal doors & blinds, sun breakers, curtain walls.

High resistance to UV.

Interpon D3000High-performance outdoor protection and decoration for architectural use. Hyper Durability.

Metal fittings, frontages, metal doors & blinds, sun breakers, curtain walls.

Outstanding resistance to UV. Excellent chemical resistance.

For any information about maintenance and repair solutions for Interpon powder coatings, use Cromadex liquid coatings solutions. Please visit our website:

www.cromadex.com

Benelux Tel: 32 (0) 2 254 77 51Czech Republic Tel: +420 553 692 275 www.interpon.czDenmark Tel: +45 44 66 44 44

EgyptTel: +20 (0) 2 38 33 1415 www.interpon.eg

Finland Tel: +358 (0) 10 8419 596

FranceDourdan (Main Office) Tel: +33 (0)1 60 81 81 81

Lille Tel: +33 (0) 32 83 36 840

Lyon Tel: +33 (0) 47 49 45 628

Marseille Tel: +33 (0) 4 91 11 61 20

Nantes Tel: +33 (0) 22 80 15 888

Paris Tel: +33 (0) 14 94 40 330

Rouen Tel: +33 (0) 23 56 41 070

Strasbourg Tel: +33 (0) 39 06 48 910

www.interpon.fr

GermanyLudwigsburg

North Tel: 0049 71 414 512 530;

South Tel: 0049 71 414 51250

www.interpon.de

Greece Tel: +30 210 8160 160 www.interpon.gr

Hungary Tel: +36 30 629 0295

India Tel. : +91 (0) 802 289 5000 www.interpon.in

Italy Tel: +39 031 345 111 www.interpon.it

Morocco Tel: +212 (0) 522 67 87 67

Poland Tel: +48 12 651 81 91Portugal Tel: +35 2121 99100

Romania Tel: + 40 21 3232 314 www.interpon.ro

Russia Tel: +7 495 411 7350 www.interpon.ru

Slovak Republic Tel: +421 415 640612

South Africa Tel: +27 (0) 11 907 8195 www.interpon.co.za

Spain Tel: +34 (9) 3 680 6900 www.interpon.es

Sweden Tel: +46 (0) 31 928 500 www.interpon.se

Tunisia Tel: +216 71 434 700 www.interpon.eg

Turkey Tel: +90 232 355 1800 www.interpon.tr

United Arab Emirates Tel: +971 4886 2181 www.interpon.ae

United KingdomBirmingham (Main Office) Tel: +44 (0) 121 558 5005

Bristol Tel: +44 (0) 117 935 4233

Bury St Edmunds Tel: +44 (0) 1359 271 072

Glasgow Tel: +44 (0) 141 427 7171

Leeds Tel: +44 (0) 113 276 0653

Manchester Tel: +44 (0) 161 848 7056

Newcastle Tel: +44 (0) 191 438 4738

Northampton Tel: +44 (0) 1604 70 66 77

Portsmouth Tel: +44 (0) 2392 201 356

Tilbury Tel: +44 (0) 1375 851 024

www.interpon.co.uk

All products supplied & technical advice given are subject to the standard terms of sale of the AkzoNobel supplying company.

Copyright ©2014 Akzo Nobel Powder Coatings Ltd. Interpon is a registered trademark of AkzoNobel.

(Issue 1 - 06/2014). Printed in the UK.

For further information, please visit our website www.interpon.com

In no case is the information given in this brochure claimed to be exhaustive. Anyone using our products for any purpose other than that recommended in this brochure without having secured our written confirmation to the effect that the product is adequate for the intended purpose does so at their own risk.

Although we take every precaution to ensure that the advice we give regarding these products (either within this brochure or elsewhere) is accurate, we have no control over the quality of substrates or their conditions, nor over the numerous factors that can affect the utilisation and application of products.

And although we do give written acceptance in the specific cases described – and exclusively in such cases – we take on no responsibility whatsoever (concerning the performance of products) for any loss or damage whatsoever that is entailed in the utilisation of such products (other than in the event of death or physical injury arising from negligence on our part).

The information comprised within this brochure may be subject to modification at any time, as new information comes to light and as our product development policy is adjusted.