SIST EN 3656:2023

Aerospace series - Polycarbonate, self-extinguishing, low smoke emission - Characteristics

This document specifies the characteristics of self-extinguishing and low smoke emission semi-finished polycarbonate sheets with and without UV radiation protection requirement, as used for aircraft equipment, such as internal panelling, simple internal glazing, sound-proofing panels, light covers, etc.

Luft- und Raumfahrt - Polycarbonat, flammgeschützt, raucharm - Eigenschaften

Dieses Dokument legt die Eigenschaften von selbstverlöschendem Polycarbonat-Halbzeug in Form von Tafeln
mit niedriger Rauchemission, mit und ohne UV-Strahlenschutzforderung fest, wie sie für die Ausrüstung von
Luftfahrzeugen, wie Innenverkleidungen, einfache Innenverglasungen, Schallisolierungsplatten, Leuchtenabdeckungen
usw., verwendet werden.

Série aérospatiale - Polycarbonate auto-extinguible, à faible émission de fumée - Caractéristiques

Le présent document spécifie les caractéristiques des tôles semi-finies en polycarbonate auto-extinguibles et à faible émission de fumée, avec ou sans exigence de protection contre le rayonnement UV, utilisées pour les équipements aéronautiques tels que les panneaux intérieurs, les vitrages intérieurs simples, les panneaux d'insonorisation, les protège-lampe, etc.

Aeronavtika - Polikarbonat, samougasljiv, majhne emisije dima - Značilnosti

Ta dokument določa značilnosti samougasljivih polizdelanih polikarbonatnih plošč z majhnimi emisijami dima, z zahtevo za zaščito pred UV sevanjem ali brez nje, ki se uporabljajo za letalsko opremo, kot so notranji opaži, preprosta notranja zasteklitev, zvočno izolacijske plošče, prekrivala za svetila itd.

General Information

• Status: Published
• Publication Date: 22-Jan-2023
• ICS: 49.025.40 - Rubber and plastics
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 04-Jan-2023
• Due Date: 11-Mar-2023
• Completion Date: 23-Jan-2023
• Ref Project: EN 3656:2022 - Aerospace series - Polycarbonate, self-extinguishing, low smoke emission - Characteristics

Overview

EN 3656:2022 - "Aerospace series - Polycarbonate, self‑extinguishing, low smoke emission - Characteristics" is a CEN standard that specifies the required characteristics for semi‑finished polycarbonate sheets used in aircraft equipment. It covers self‑extinguishing, low smoke emission polycarbonate sheets with or without UV protection for uses such as internal panelling, simple internal glazing, sound‑proofing panels and light covers. The standard defines material condition, surface finish, physical, optical, mechanical, thermal and flammability requirements and references related technical specifications.

Key topics and requirements

• Scope and field of application
  • Semi‑finished extruded sheet for aerospace components not subject to specific heat‑emission fire regulations.
  • Surface finish: smooth or textured.
  • Reprocessed content limits: up to 20% for colourless/transparent, up to 50% for coloured opaque.
• Reference documents
  • EN 2719 (polycarbonate sheet technical specification), EN 3779 (dimensions) and ISO 554 (conditioning).
• Physical / mechanical
  • Density: 1.18–1.24 g/cm³.
  • Tensile stress at yield: ≥ 50 MPa.
  • Tensile strain at yield: ≥ 55%.
  • Modulus of elasticity: ≥ 2 000 MPa (for thickness ≥ 4 mm noted).
  • Water absorption: ≤ 30 mg.
• Thermal
  • Temperature of deflection under load: 128 °C.
  • Vicat softening temperature: 140 °C.
  • Linear thermal expansion coefficient and other thermal properties specified.
• Optical
  • Refractive index: ~1.59 D.
  • Visible light transmission: e.g. 73% at 2 mm, 72% at 3–6 mm, 69% at 12 mm (colourless types).
  • Optical defects, deviation and distortion criteria to be agreed between customer and manufacturer.
• Flammability and smoke
  • Smoke density limits with flame exposure: 100 (within 1.5 min) and 200 (within 4 min).
  • Fume gas component maximum concentrations (ppm) after 4 min: HCl 150, HF 100, HCN 150, SO2/H2S 100, NO+NO2 100, CO 3 500.
• Testing and conformity
  • Qualification testing: full set of characteristics demonstrated on three production batches.
  • Acceptance testing: specified subset of tests (per standard footnotes) performed on production batches.
  • Conditioning per ISO 554 prior to testing.

Applications and users

• Typical users: aerospace manufacturers, material suppliers, procurement teams, design and qualification engineers, quality assurance and certification bodies involved in aircraft interiors and non‑structural equipment.
• Typical applications: internal panelling, simple internal glazing, light covers, acoustic panels and other interior components where low smoke and self‑extinguishing behavior is required.

Related standards

• EN 2719 - Aerospace series - Polycarbonate sheet - Technical specification (detailed material/process requirements)
• EN 3779 - Aerospace series - Polycarbonate sheet - Dimensions (designation and sizing)
• ISO 554 - Standard atmospheres for conditioning and/or testing

EN 3656:2022 provides a clear, testable set of characteristics for specifying and verifying semi‑finished aerospace polycarbonate sheets where fire performance (low smoke, self‑extinguishing) and optical/mechanical properties are critical.

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2023
Aeronavtika - Polikarbonat, samougasljiv, majhne emisije dima - Značilnosti
Aerospace series - Polycarbonate, self-extinguishing, low smoke emission -
Characteristics
Luft- und Raumfahrt - Polycarbonat, flammgeschützt, raucharm - Eigenschaften
Série aérospatiale - Polycarbonate auto-extinguible, à faible émission de fumée -
Caractéristiques
Ta slovenski standard je istoveten z: EN 3656:2022
ICS:
49.025.40 Guma in polimerni materiali Rubber and plastics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 3656
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2022
EUROPÄISCHE NORM
ICS 49.025.40
English Version
Aerospace series - Polycarbonate, self-extinguishing, low
smoke emission - Characteristics
Série aérospatiale - Polycarbonate auto-extinguible, à Luft- und Raumfahrt - Polycarbonat, flammgeschützt,
faible émission de fumée - Caractéristiques raucharm - Eigenschaften
This European Standard was approved by CEN on 24 July 2022.

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-CENELEC 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-CENELEC 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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3656:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Field of application . 4
4.1 Typical application . 4
4.2 Material condition . 4
4.3 Surface finish . 4
5 Required characteristics . 4
6 Designation . 5
7 Technical specification . 5

European foreword
This document (EN 3656:2022) has been prepared by the Aerospace and Defence Industries
Association of Europe — Standardization (ASD-STAN).
After enquiries and votes carried out in accordance with the rules of this Association, this document has
received the approval of the National Associations and the Official Services of the member countries of
ASD-STAN, prior to its presentation to CEN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by June 2023, and conflicting national standards shall be
withdrawn at the latest by June 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not
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