IEC 60763-3-1:2010

IEC 60763-3-1 ®
Edition 2.0 2010-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Laminated pressboard for electrical purposes –
Part 3: Specifications for individual materials – Sheet 1: Requirements for
laminated precompressed pressboard, Types LB3.1A.1 and LB3.1A.2

Cartons comprimés et contrecollés à usages électriques –
Partie 3: Spécifications pour matériaux particuliers – Feuille 1: Exigences
relatives aux cartons précomprimés contrecollés, Types LB3.1A.1 et 3.1A.2

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IEC 60763-3-1 ®
Edition 2.0 2010-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Laminated pressboard for electrical purposes –
Part 3: Specifications for individual materials – Sheet 1: Requirements for
laminated precompressed pressboard, Types LB3.1A.1 and LB3.1A.2

Cartons comprimés et contrecollés à usages électriques –
Partie 3: Spécifications pour matériaux particuliers – Feuille 1: Exigences
relatives aux cartons précomprimés contrecollés, Types LB3.1A.1 et 3.1A.2

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
E
CODE PRIX
ICS 29.035.10 ISBN 978-2-88912-144-1
– 2 – 60763-3-1 © IEC:2010
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LAMINATED PRESSBOARD FOR ELECTRICAL PURPOSES –

Part 3: Specifications for individual materials –
Sheet 1: Requirements for laminated precompressed pressboard,
Types LB3.1A.1 and LB3.1A.2
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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with the International Organization for Standardization (ISO) in accordance with conditions determined by
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60763-3-1 has been prepared by IEC technical committee 15:
Solid electrical insulating materials.
This second edition cancels and replaces the first edition published in 1992. This edition
constitutes a technical revision.
The main changes with respect to the previous edition are listed below:
– requirements for the new properties in Part 2 have been integrated;
– specifications for type LB3.3.1 and LB3.3.2 have been deleted.

60763-3-1 © IEC:2010 – 3 –
The text of this standard is based on the following documents:
CDV Report on voting
15/537/CDV 15/567/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
Future standards in this series will carry the new general title as cited above. Titles of existing
standards in this series will be updated at the time of the next edition.
A list of all the parts in the IEC 60763 series can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 4 – 60763-3-1 © IEC:2010
LAMINATED PRESSBOARD FOR ELECTRICAL PURPOSES –

Part 3: Specifications for individual materials –
Sheet 1: Requirements for laminated precompressed pressboard,
Types LB3.1A.1 and LB3.1A.2
1 Scope
This sheet of IEC 60763-3 gives the requirements for laminated precompressed boards
comprised of 100 % sulphate wood pulp.
Materials which conform to this specification meet established levels of performance.
However, the selection of a material by a user for a specific application should be based on
the actual requirements necessary for adequate performance in that application and not
based on this specification alone.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60763-1:2010, Laminated pressboard for electrical purposes – Part 1: Definitions,
classification and general requirements
IEC 60763-2:2007, Specification for laminated pressboard – Part 2: Methods of test
3 Designation
LB3.1A.1 – laminated precompressed board made from 100 % sulphate wood pulp, bonded
with a casein-type glue.
LB3.1A.2 – laminated precompressed board made from 100 % sulphate wood pulp, bonded
with a non-aqueous resin.
4 General requirements
Materials shall conform to the general requirements given in IEC 60763-1 and to the specific
requirements of the appropriate type given in Table 1 of this sheet when tested according to
the methods stipulated in IEC 60763-2.

60763-3-1 © IEC:2010                  – 5 –

Table 1 – Specific requirements with regard to the appropriate type of board
LB3.1A.1 LB3.1A.2
Bonding agent
Casein Non-aqueous
Test method
(clause or
Property Unit Max. or Min.
subclause of
IEC 60763-2)
Thickness deviation
≤ 12 mrn 5.1 % Max. 5 5
% Max. 4 4
> 12mm
Flatness 500 mm
< 20 mm 5 4
5.1.4 mm Max.
20 to 50 mm 3 2
2 1
> 50 mm
Flexural strength
6.1
MD MPa Min. 100 110
CMD MPa Min. 80 90
Compressibility :
C 7.1 % Max. 3.5 3
C % Min. 65 70
rev
Electric strength in oil
8 kV/mm
Parallel to layers Min. 8 8
Internal ply strength
Dried, tested at 23 °C MPa Min. 80 90
Dried, tested at 120 °C, retention 9 % Min. 60 60
Oil impregnated, tested at 23 °C, retention % Min. 80 80
Aged for 1 week at 120 °C in oil, tested at 23 °C retention % Min. 90 90
Apparent density 10 g/cm Range 1,15 – 1,3 1,15 – 1,35
Moisture content 11 % Max. 8 5
Shrinkage:
MD % Max. 0,5 0,4
CMD % Max. 0,7 0,6
Thickness % Max. 6 4
Oil absorption 13 % Min. 6 5
To be agreed between supplier and
Ash content 14 %
purchaser
Contamination of dielectric liquids
Neutralisation value mg KOH/g ± 0,08 0,05
Sludge content mg/l Max. 500 500
Dissipation factor 0,005 0,005
±
Conductivity of aqueous extract 16 mS/m Max. 15 10
pH of aqueous extract 17 Range 6 - 10 5 - 8
_______________
– 6 – 60763-3-1 © CEI:2010
COMMISSION ÉLECTROTECHNIQUE INTERNATIONALE
____________
CARTONS COMPRIMÉS ET CONTRECOLLÉS
À USAGES ÉLECTRIQUES –
Partie 3: Spécifications pour matériaux particuliers –
Feuille 1: Exigences relatives aux cartons précomprimés contrecollés,
Types LB3.1A.1 et 3.1A.2
AVANT-PROPOS
1) La Commission Electrotechnique Internationale (CEI) est une organisation mondiale de normalisation
composée de l'ensemble des comités électrotechniques nationaux (Comités nationaux de la CEI). La CEI a
pour objet de favoriser la coopération internationale pour toutes les questions de normalisation dans les
domaines de l'électricité et de l'électronique. A cet effet, la CEI – entre autres activités – publie des Normes
internationales, des Spécifications techniques, des Rapports techniques, des Spécification
...