EN 2434-004:2010

Aerospace series - Paints and varnishes - Two component cold curing polyurethane finish - Part 004: High flexibility

This European Standard specifies the requirements for a two component polyurethane finish to be applied over a primer mainly for exterior aerospace applications, offering high flexibility
The properties specified in this European Standard are obtained on defined aluminium alloy test pieces prepared in accordance with EN 3837 and EN 23270 and painted with primer to prEN 2435-002. The ability of the material to be used for a specific application (e.g. alternative substrate, alternative primer, specific drying conditions etc.) shall be determined by supplementary tests to confirm that the requirements of this standard are met.

Luft- und Raumfahrt - Beschichtungsstoff - Zweikomponenten- Polyurethan-Decklack, kalthärtend - Teil 004: Hohe Elastizität

Diese Europäische Norm legt die Anforderungen an eine Zweikomponenten-Polyurethan-Deckbeschichtung fest, die auf einen Primer hauptsächlich für Außenanwendungen in der Luft- und Raumfahrt aufzubringen ist, und eine hohe Elastizität aufweist.
Die in dieser Norm festgelegten Eigenschaften werden an festgelegten Probenkörpern aus Aluminium-legierung ermittelt, die nach EN 3837 sowie nach EN 23270 hergestellt und mit Primer nach EN 2435 002 beschichtet wurden. Die Eignung des Werkstoffes für eine bestimmte Anwendung (z. B. alternativer Trägerwerkstoff, alternativer Primer, bestimmte Trocknungsbedingungen usw.) ist durch zusätzliche Prüfungen zu ermitteln, um zu bestätigen, dass die Anforderungen dieser Norm erfüllt werden.

Série aérospatiale - Peintures et vernis - Peinture de finition polyuréthane, à deux composants, polymérisant à température ambiante - Partie 004: Haute flexibilité

Aeronavtika - Barve in laki - Dvokomponentni poliuretanski končni premaz, ki se suši pri sobni temperaturi - 004. del: Visoka elastičnost

Ta evropski standard določa zahteve za dvokomponentni poliuretanski končni premaz, ki se nanese čez temeljni premaz, pretežno za zunanjo uporabo v aeronavtiki, ki zagotavlja visoko elastičnost. Lastnosti, določene v tem evropskem standardu, so pridobljene na definiranih preskusnih kosih aluminijeve zlitine, pripravljenih v skladu z EN 3837 in EN 23270, in premazanih s temeljnim premazom v prEN 2435-002. Sposobnost materiala, da se uporablja za posebna področja uporabe (npr. alternativni substrat, alternativni temeljni premaz, posebni pogoji sušenja itd.), se določi z dodatnimi preskusi, s katerimi se potrdi, da so zahteve tega standarda izpolnjene.

General Information

• Status: Published
• Publication Date: 31-Aug-2010
• Withdrawal Date: 30-Mar-2011
• ICS: 49.040 - Coatings and related processes used in aerospace industry
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 5 - Non-Metallic
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 01-Sep-2010
• Completion Date: 01-Sep-2010
• Ref Project: SIST EN 2434-004:2010 - Aerospace series - Paints and varnishes - Two component cold curing polyurethane finish - Part 004: High flexibility

Overview

EN 2434-004:2010 is a European standard developed by CEN, focusing on aerospace industry coatings. It specifies the requirements for a two-component cold curing polyurethane finish designed primarily for exterior aerospace applications. This finish is characterized by its high flexibility, making it suitable for use on aluminium alloy substrates typically found in aerospace structures. The standard ensures that the coating offers reliable performance under various environmental conditions while maintaining excellent mechanical and chemical properties.

The standard outlines testing methodologies, material formulations, and application procedures to guarantee consistent quality and adherence to aerospace industry demands.

Key Topics

• Material Composition
  The finish consists of two components:

  • A base containing hydroxyl functional resin, solvents, and pigments
  • An activator solution based on polyisocyanate
    These components are mixed in defined proportions to ensure optimal curing and film properties.

• Surface Preparation and Application
  Application is intended over primers compliant with prEN 2435-002, applied on aluminium alloy test pieces prepared per EN 3837 and EN 23270 standards. The finish requires drying times and curing conditions aligned with EN 23270.

• Physical and Chemical Properties
  The finish must achieve:

  • Dry film thickness of 50 ± 5 µm
  • High gloss finish (≥ 80 units at 60°) or customizable gloss levels
  • Controlled volatile organic compound (VOC) content to meet environmental regulations
  • Stable viscosity and sedimentation ratings ensuring ease of application and consistency

• Mechanical Characteristics
  The coating offers:

  • Outstanding adhesion to aluminium alloys, with classification ≤ 1 indicating excellent bonding
  • Resistance to impact, scratches (≥ 1500 g), and slow deformation without cracking or detachment
  • High flexibility demonstrated by successful cylindrical mandrel bend tests at low temperatures (−55 ± 2 °C)

• Environmental Resistance
  The polyurethane finish withstands:

  • Heat exposure at 150 °C for 24 hours without cracking or detachment
  • Cold exposure at −40 °C for 24 hours with maintained flexibility
  • Humidity of 100% at 40 °C for 500 hours with no film defects
  • Resistance to fluids including tri-n-butyl phosphate under stringent conditions
  • Artificial weathering simulating UV exposure and humidity cycles, maintaining color and gloss stability

• Quality Assurance & Testing
  The standard mandates both batch release and qualification tests covering physical, mechanical, and environmental factors to ensure product consistency and compliance with aerospace quality levels.

Applications

EN 2434-004:2010 is tailored for the aerospace sector, specifically for exterior coatings on aircraft components where flexibility and durability are critical. Its key applications include:

• Aircraft Exteriors
  Protecting aluminium airframe surfaces from corrosion, UV degradation, and mechanical wear while accommodating structural flexing.

• Maintenance and Repair
  Suitable for use in repair coatings and refinishing of aerospace parts requiring cold curing to minimize downtime.

• Aerospace Manufacturing
  Ideal for application in aerospace production lines for durable, flexible topcoats over corrosion-resistant primers.

• Specialized Aerospace Components
  Can be considered for flexible finishes on parts exposed to variable temperature ranges and harsh environmental exposure.

Related Standards

For comprehensive aerospace coating systems, EN 2434-004:2010 references and complements several other standards:

• EN 2435-002 – Corrosion resistant chromated two-component cold curing primer with high corrosion resistance
• EN 3837 – Surface preparation methods for aluminium alloy test pieces
• EN 23270 – Conditioning and drying conditions for paints and varnishes
• EN 3840 – Technical specifications for paint and varnish test methods
• EN 4385 – General organization of aerospace non-metallic materials standardization
• EN 7000-9 – Drafting rules for paint and varnish standards in aerospace materials
• EN ISO 1513 – Sample examination and preparation for testing paints
• EN ISO 3696 – Specifications for water quality in analytical testing

Compliance with these standards ensures synergy in aerospace coating applications, promoting high performance and safety in critical aerospace components.

---

EN 2434-004:2010 is essential for manufacturers, coating formulators, aerospace maintenance providers, and quality assurance teams seeking a reliable, high-flexibility polyurethane finish. Its strict requirements ensure coatings that deliver openness to environmental extremes, mechanical stress, and chemical exposure, making it vital in aerospace paint systems.

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Luft- und Raumfahrt - Beschichtungsstoff - Zweikomponenten, Polyurethan-Decklack, Kalthärtend - Teil 004: Hohe ElastizitätSérie aérospatiale - Peintures et vernis - Peinture de finition polyuréthane, à deux composants, polymérisant à température ambiante - Partie 004: Haute flexibilitéAerospace series - Paints and varnishes - Two component cold curing polyurethane finish - Part 004: High flexibility49.040Prevleke in z njimi povezani postopki, ki se uporabljajo v letalski in vesoljski industrijiCoatings and related processes used in aerospace industryICS:Ta slovenski standard je istoveten z:EN 2434-004:2010SIST EN 2434-004:2010en,de01-december-2010SIST EN 2434-004:2010SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 2434-004
September 2010 ICS 49.040 English Version
Aerospace series - Paints and varnishes - Two component cold curing polyurethane finish - Part 004: High flexibility
Série aérospatiale - Peintures et vernis - Peinture de finition polyuréthane, à deux composants, polymérisant à température ambiante - Partie 004: Haute flexibilité
Luft- und Raumfahrt - Beschichtungsstoff - Zweikomponenten- Polyurethan-Decklack, kalthärtend - Teil 004: Hohe Elastizität This European Standard was approved by CEN on 6 February 2010.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 2434-004:2010: ESIST EN 2434-004:2010

EN 2435-002, Aerospace series — Paints and varnishes — Corrosion resistant chromated two component cold curing primer – Part 002: High corrosion resistance
EN 3837, Aerospace series — Paints and varnishes — Nature and method for surface preparation of test pieces in aluminium alloys 1) EN 3840, Aerospace series — Pieces paints and varnishes — Technical specification
EN 4385, Aerospace series — Non-metallic materials — General organisation of standardisation — Links between types of standards 1) EN 7000-9, Aerospace series — Non-metallic materials — Rules for the drafting and presentation of material standards — Part 9: Paints and varnishes 1) EN 23270, Paints, varnishes and their raw materials — Temperatures and humidities for conditioning and testing (ISO 3270:1984)
1)
Published as ASD-STAN Prestandard at the date of publication of this standard SIST EN 2434-004:2010
...